/ Home & Energy

Is it worth paying for boiler cover?

Our annual boilers survey has revealed a surprising nugget: those who pay for boiler cover could be better off forgoing their contract and paying for repairs on an ad-hoc basis. Do you pay for boiler cover?

Almost half of gas and oil boilers will develop at least one fault that needs a repair within the first six years of its life. Of course, getting yourself a Which? Best Buy boiler is a good idea, and drops this to fewer than two in five.

Despite the likelihood that your boiler will eventually develop some faults, we’ve found most people who own a boiler would be £50+ a year better off without boiler cover.

We compared the cheapest servicing contract (£183 per year), which includes an annual service, against the experiences of 5,322 Which? members who don’t have cover. Instead, these members paid for repairs on an ad-hoc basis as well as a yearly boiler check-up. The great majority (93%) are still better off without boiler cover to the tune of £50 or more.

My boiler servicing story

I’ve owned my combi gas boiler for just over three years now, having inherited it when I got the keys to my two-bed flat. I’ve never paid for boiler cover, but I have incurred some costly repairs. Here’s my story (violins).

About two years ago I woke up on a bank holiday weekend with water leaking from somewhere within the casing of the boiler. Being a bank holiday it was difficult to get hold of a plumber, but eventually I found one who was willing to interrupt his weekend to come out and take a look. He diagnosed the problem as a couple of corroded washers and came back the following day to replace them. The cost of the parts that needed replacing – £15. Total cost of call-out and repair on a bank holiday – £261. Ouch.

As a result of that rude introduction to boiler maintenance, I now pay £85 for a service each year to keep my boiler in good working order.

So in the three years I have owned my boiler, I calculate that it has cost me £431 to maintain it. This is the first time I’ve added it up and that seems like a lot for three years – I keep my fingers crossed that I won’t need any more costly repairs going forward!

My experience tallies pretty well with the results of our survey – even though I had a pretty costly repair to shell out for in one year, one of the unlucky few; I would have had to pay at least £549 over the last three years for even the cheapest boiler cover contract, so I am now more than £100 up.

I’ll continue to pay for an annual service and then any repairs as they come up as, despite my bad experience, I don’t see much value in a servicing contract at the moment. I might get scalded again with costly repairs, but for now it feels like an acceptable risk.

Your boiler servicing stories

So, how about you? I would love to hear about how much your boiler has cost you. Are you, like me, in the 93% who are better off without insurance? Or one of the unlucky 7% who have incurred very costly repairs?

Further, are we giving boiler cover too much of a hard time? It would be great to hear from those of you who have had great value from one of these contracts.


Wavechange: The replacement thermocouple is still operational over 12 months later. What I would like to know is why the original thermocouple was replaced when it was working perfectly and replaced with an inferior one. “Normal practice” does not assuage my enquiring mind and questions remain whether they get swopped around between different customers boilers until they eventually fail and some unsuspecting person ends up like I did with an enormous bill just to cover call out fees and labour. This I know will probably be vehemently denied by our engineer friends and participants but it is a practice that has definitely occurred in the past under the guise of ‘reconditioned parts.’

I have been lucky with thermocouples. The current one is about 14 years old and I bought it for £2 in a closing down sale, several years before it was needed. On the other hand, the thermocouple on my parents’ boiler needed replacement every few years.

There is no doubt that faulty thermocouples are a common cause of boiler failure. If you were left without heating over a cold Christmas, you could argue that the service engineer should have replaced the thermocouple during the annual service, particularly if they had no idea how old it was.

In his introduction, Matt wrote: “About two years ago I woke up on a bank holiday weekend with water leaking from somewhere within the casing of the boiler. Being a bank holiday it was difficult to get hold of a plumber, but eventually I found one who was willing to interrupt his weekend to come out and take a look. He diagnosed the problem as a couple of corroded washers and came back the following day to replace them. The cost of the parts that needed replacing – £15. Total cost of call-out and repair on a bank holiday – £261. Ouch.”

If you request a repair, it is reasonable to expect the service engineer to come equipped with parts that they are likely to need to carry out the repair of that make and model, especially if it a current or recently manufactured appliance. It is possible that the ‘corroded washers’ were in fact a specialist part for that model of boiler. If they were commonly used sealing washers, it would be fair to ask the company why their engineer did not carry a stock. I do hope that the £15 charge for parts covered more than replacement of simple washers.

To help ensure that repairs are carried out at the first visit it is important to give as much relevant information as possible (e.g. make, model, serial number and age) and an accurate description of the fault.

I think when the last service engineer called he very politely, whilst suggesting I get a new boiler, mentioned that they stopped making spares for my boiler back in 1998.

The which report cites 49% of boilers develope a fault with in 6 years, a truly shocking statistic in my professional opinion, I don’t know why the public put up with it. However the perception that boilers are problematic and accepted by the public gives the manufactures no motivation to change the way they train and support installers, so the good nature of the pubic just gets exploited.

Condensing boilers are designed for constant flow and variable flow temperatures and “challenged” by TRVs said and ficed, high temperatures. As I have previously said, chemicals are best avoided, and permanent filters used instead.

If I were Which I would be talking with consumers associations in Germany to share experiences…

Alec – How do you propose that we control the temperatures of individual rooms if we don’t have TRVs on the radiators or more sophisticated systems such as zone control?

Without corrosion inhibitors, the radiators will be damaged by oxidative and electrolytic corrosion. What is wrong with these products, which have been used successfully for decades?

I’m not sure what you mean by filters, perhaps because I have little knowledge of modern systems. Can you explain what these do, please?

I very much support consumers’ organisations exchanging information.

Alec, while I’m not an installer I find it difficult to understand a presumption against adding an inhibitor. Or to put it another way, not adding an inhibitor is likely to be a worse decision.

Hi Alec, I am also a little puzzled by your aversion to chemicals, specifically corrosion inhibitors which are a slightly alkaline & if you feel the diluted solution [say on a radiator drain down] it is slightly “soapy”. Just for information I always collect as much of the drain down water & recycle it back to the open vented system head tank, having isolated the fresh water feed to it before starting any draining operations. Now I appreciate that this is only possible on older systems – and this why I like them!
I have no experience of using magnetic or other filters but I have read about them & noticed that they are really quite expensive. With my engineer’s/common sense/practical hat on I have some reservations about them. I am sure that they are very good at trapping suspended solids in the water flowing through them BUT if they are introduced into an older system which has not been chemically treated it most likely that there will deposits of sludge/corrosion products that are not suspended and which have settled in low flow velocity areas of the system – classically at the bottom of radiators below the water entry/exit centreline. This type of accumulation in fact accelerates corrosion and ultimately leads to leaking radiators.
So I would venture the opinion that neither power flushing or fancy filters will give as good a result as a rigorously performed chemical clean. Even with new copper systems these are recommended to flush out plumbers flux & any other debris. I appreciate that with modern push fit plastic pipework this is not relevant but steel radiators are still the major component outside the boiler.

My boiler is only 9 years old and I have had a British Gas maintenance contract since moving in 8 years ago. At the last annual visit I was informed that British Gas are reducing the stocking of spares for my boiler. So does this mean I can pay for an expensive service only to have them say they can’t carry out any repairs that may be needed? Are boilers expected to thrown away after less than 10 years?

On other Conversations I have been suggesting that household appliances should come with a ten year warranty. Paying for an extended warranty can be expensive and Which? has frequently told us these are often poor value for money.

Having now read the article about boilers in the October issue of Which? I am pleased to see that some come with manufacturers warranties of five or ten years. A fifteen year warranty is available with Glow-worm boilers, but the catch is that to qualify it is necessary to use a specified installer, which might be an expensive option.

There are still some boilers that have only a one year manufacturer’s warranty, but in general the industry seems to be moving in the right direction. If a manufacturer provides a long warranty, they are responsible for the costs of repairs, so it would not make sense to make boilers that use substandard and unreliable components. That helps the customer because they are better protected from unforeseen expense and the danger of being left without heating.

One of the issues the industry has is that almost all boilers in the UK work to a set temperature, where as they all have to incorporate and accept controls that vary the temperature of the boiłer in relation to the deviation of actual room temperature and programmed temperature. All imstallers and the public need to do is to select a comoensation controller as opposed to an on off controller, and set it up correctly. Ring the boiłer manufacturers technical help line for information.

Pumps do run longer, but almost universally people have heating to be comfortable, and a lomger running pump at a variable temperature provides stable room temperarures. A new EU regulation is driving down the energy consumption of pumps, and nowadays these can be as low as 7w for a whole house..

with respect to inhibitors, they are rarely used in Germany. I don’t use inhibitors, instead I use a filter which catches particles.The installs that I did treat with inhibitors all seem to have developed. Of course flux etc should be flushed out.

The heating industry is one where perception dominates not hard facts… prevention (a filter) is always better than cure (inhibitors)

Alec – You say that “prevention (a filter) is always better than cure (inhibitors)”. But it is the corrosion inhibitors that prevent steel radiators from corroding.

Regarding use of chemicals, I agree that using strong acids for cleaning heating systems is undesirable, both on safety grounds and because they will cause some damage. There are much safer products for cleaning new systems and those that have not been protected from corrosion.

I don’t know why the industry has used the term ‘filter’ for devices that use magnets to collect circulating particles. As a scientist I object to misuse of hitherto well understood terms. 🙁

I was once informed by a heating engineer that corrosion is more common in soft water areas. Having read all the posts leaves me little confused so I have carried out my own research on this topic and discovered that corrosion inhibitors are only necessary in homes with water softeners due to the salt content coming into contact with heat exchangers although water softener manufacturers will obviously deny this. As natural soft water would not contain the same amount of salt, was I misled by the heating engineer? As water softeners are more likely to be used in hard water areas where I live, some enlightenment would be appreciated please.

Hi Beryl,
My thoughts on this is that high water hardness will give rise to scale or lime like deposits – you will know if you have hard water just look at your kettle element. If it’s encrusted with white/grey/light brown material you have hard water. If it’s not, or has only light scaling [< 0.2 mm thick after 6 months use] then this would indicate relatively soft water. For modern sealed & pressurised systems in hard water areas it certainly sounds sensible to make sure they are filled with softened water to avoid scale deposits within the system.
Now whilst corrosion under or adjacent to scale build ups may well be possible it is not the same problem as is caused [albeit in older open vented systems] where dissolved oxygen will attack unprotected steel surfaces. So here are two distinct potential problems here, scale AND corrosion.
From my experience I would not agree with your research finding that inhibitors are only needed where water softeners are in use.

As far as I am aware, domestic water softeners are based on ion exchangers that remove calcium and magnesium ions with other ions such as sodium. That prevents limescale formation but since water softened in this way remains electrically conductive, it will not prevent electrolytic corrosion. It would not cost much to fill up a heating system with purified water that is superior even to distilled water. In a modern system that lacks a header tank, there should be no need to add more water unless there is a leak.

Though the cost of proper purified water is not great, the equipment needed to make it is expensive and it would be inconvenient to transport it. I live in a hard water area and had thought about filling my system with purified water but found that corrosion inhibitor on its own was very effective.

Just to avoid any confusion between the different words/terminology used by scientists & engineers.
Black sludge found in older central heating systems, which is largely iron oxide, is the result of “electrolytic corrosion” & “corrosion caused by dissolved oxygen”. No doubt someone will tell me that they are different, but to all intents & purposes, & for the readership of these posts, they are the same thing. Either way inhibitors prevent this kind attack on steel radiators.

as does sealing a system. In sealed systems once the dissolved oxygen has reacted with the steel the water becomes inert.

Today I was working on a well designed openvented system installed in 1953, made of barrel steel.It hgas 84 radiators and Some radiators had been changed to aluminium, the water was so clean you could drink it, if so inclined.

I am no expert but I would expect the aluminium radiators to act as sacrificial anodes, gradually dissolving but protecting the steel.

In a sealed system, there is a limited amount of dissolved oxygen, the solubility being only 10mg per litre at room temperature, so that corrosion caused by dissolved oxygen is unimportant compared with electrolytic corrosion.

I expect that our moderators are wondering why we are off topic, but there is no doubt that radiator corrosion has an adverse effect of the reliability and life of central heating systems.

This is what I find so annoying about the UK is that with establishments like the BRE and univeersities galore there appears to be no science in the various suggestions here and on some boiler manufacturers sites.

I do not expect definite cures but it would be interesting to see how long a system runs without problems with corroded metal. If it is 5 – 10 -20 years it would be helpful. I am fully aware that these results would need to consider water qualities also but there does seem to be a lack of base line figures.

This is interesting:
” Many cast iron radiators last 100 years or more, and when they do break they can be fixed by replacing just the damaged section. A typical life expectancy for a steel panel radiator is just 25 years, and a broken steel radiator often needs to be completely replaced. So comparing the initial carbon footprints of steel and cast iron radiators is only part of the story. During the 100 year life span of a cast iron radiator, an equivalent steel radiator could have been replaced four times.
Although cast iron radiators have a bigger up front impact in terms of their carbon footprint, they are the clear winner over modern steel panel radiators due to their long life spans. It should come as no surprise that investing in good quality products, that last, makes environmental sense.”

As far as I am aware, steel radiators are reasonably durable provided that corrosion inhibitors are used in the system. Mine are well over 30 years old and I have had no problems whatsoever. Where neighbours and friends have replaced their radiators has been for decorative purposes or to install higher output double units, rather than because of failure.

I am keen on product durability and conserving natural resources, but I believe it would be better to focus on improving the life expectancy of boilers, some of which are scrapped after just a few years.

It’s not quite true to say that there’s no science here. Prompted by your comment, DieselTaylor, I found a paper on “The testing of corrosion inhibitors for central heating systems” by P Munn of Fernox in Corrosion Science, 1993.

Forgive me for changing the subject slightly but I wonder whether we might shift from the circulating water to the electronics. There are reports here of “the electronics” being replaced on relatively recent boilers due to early failure. I wonder how much the electronics is the cause of failure in general in boilers. There’s another thread on white goods and certainly the electronics on those products tend to fail more than they should. The automotive manufacturers seem to have generally managed to construct reliable electronics for harsh environments. What’s the problem in domestic appliances and boilers? Is it purely a cost thing?

We know that domestic goods are going to get more and more of their functionality delivered by electronics. What can be done to ensure that this does not come at the price of poor reliability? And which manufacturers have managed to crack this problem?

There is absolutely no reason why boiler control electronics should not outlast the boiler in the vast majority of cases. Having designed and built electronic equipment I can be sure of this. The electronic components have to be adequately rated and protected from heat, moisture and voltage spikes, but this is not difficult. As you say, car manufacturers have largely overcome these problems. I would expect a spark igniter to be the weakest point, but that should be an inexpensive and easily replaceable module. If manufacturers try to save a few pennies then reliability could be compromised. If ten year warranties become standard then manufacturers would be foolhardy to risk having to fund free repairs, so long warranties are likely to result in improved reliability.

Earlier, I mentioned a case where a chap servicing an oil-fired boiler had replaced the main circuit board in the hope of fixing an intermittent fault. If I had not asked him to put the old board back after replacement failed to sort the problem, I expect that this would have been wrongly recorded as a failure of a circuit board. I expect that perfectly good components are replaced on a regular basis when trying to track down faults. When service engineers’ time has to be paid for, there is some merit in changing parts in case they are faulty. This may make boilers look less reliable than they are.

Jak – Thanks for the details of the paper by Munn. Apart from an unfortunate error where they refer to their ‘new toxic inhibitor’ 🙂 it looks to be good work and is published in a peer reviewed journal.

Like many people, I tend to disregard papers by people working in industry, which may be why the only citation of this paper in other articles is by the author himself. I believe it is far better if research is published by those working in universities or other independent organisations. Any respectable journal will require the authors to declare any interest, such as industrial funding.

What we could do with is an authoritative article written by an expert at a level that can be understood by those installing heating systems and hopefully the members of the general public that are interested in the subject.

I don’t think long warranty’s will do anything for any one to be honest… the small print will let the manufacturers off the hook, and installers will once again be blamed…no doubt when the inhibitor has caused the issue..

Britain’s heating industry isn’t known as a Cash Machine for foreign manufacturers for nothing…

Alec – Can you give us any links to disadvantages of inhibitors or cases in which boiler manufacturers have rejected warranty claims as a result of their use? I cannot claim any great knowledge, but my impression is that these products are highly regarded in the UK.

I have just looked at the manual for a Worcester Bosch ‘Greenstar’ condensing boiler. The instructions refer to the use of an inhibitor:

“INHIBITOR (Central Heating):
Check drain c***s are closed and all radiator valves are open before adding a suitable inhibitor (or combined inhibitor/ anti-freeze if the system is exposed to freezing conditions) to the heating system water in accordance with the manufacturers instructions.”

Contact details for Fernox and Sentinel are provided.

I do know installers who have fallen out with manufacturers on this subject, but installers don’t have means of expression or time to dedicate to righting the wrongs of the industry, so you won’t find many negative views on the net..

Manufacturers know that once a boiler is mended its history, by that I mean the installer gets the blame for water quality, the boiler get repaired by the client who pays and that’s the end of the matter. the installers reputation trashed..the boiler manufacturs reputation intact..but the clients heating working, and promptly looses interest in the boiler, heating and installer…

viessmann don’t really recomend the use of inhibitors on sealed systems, you could ring their technical department to see what they say..

Inhibitors are a big industry, why would any one doubt their effectiveness?

I found the following online in a German/English manual for a Viessmann VITODENS 100 condensing gas boiler:
“Additives from the approved list below may be used. The use of non approved additives will invalidate the warranty on this product.
& Anti-scaling: Sentinel X200
& Anti-bacterial:
– – System Cleaner (Fernox) – – Sentinel X300…
& Anti-freeze:
– – Glycol (30% max.)
– – Antifreeze (Fernox) – – Sentinel X500…
& Anti-corrosion:
– – Inhibitor (Fernox)
– – Sentinel X100…
& Cleaner:
– – Cleanser (Fernox) – – Sentinel X300…”

Viessmann may have rejected inhibitors, but they were happy with them in 2006, when these installation and servicing instructions were published.

The book says “may be used”, not “must be used”.

This is an industry where perception counts over experience, and objectivity goes out the window, because of huge interests, and low expectations from the consumer.

Getting back on topic, in Germany boilers are servicd according to hours of usage, relayed accross the Internet, and billed as “low maintenance” and “reliable”, which they can be.

The well respect chimney sweep who wears a top hat dies annual inspections of the flue, hence the chimney sweep mode on German boilers.

Exporters generally won’t interfere with “other” markets and local management is given free reign over the product in return for high sales volumes. Hence the “part changing” that goes on. Whether a boiler in the UK is reliable or not is of no consequence to the manufacturers, all that matters that the brand is bought again… that’s why Bosch sponsor the weather, and don’t educate installers for higher standards…

Alec – I hope you will accept that corrosion of radiators is a common problem in the UK, and it is common practice to use corrosion inhibitors in central heating and water heating systems.

I have no knowledge about practices in Germany or other countries, but I assume that corrosion of steel radiators and the problems that this can cause are no different. If not, why not?

In the UK, all gas appliances in rented properties must be inspected annually by a Gas Safe registered person and the general recommendation is that boilers should be serviced annually.

no it’s not a common problem, and I am an installer. It is common practice to use inhibitors, but I doubt the wisdom of this, and actually see that over time they cause another set of issues, in dissolved metals baking on heat exchangers surfaces, the bits breaking off an causing failures.

By contrast a system flushed with mains water, and fitted with a filter can give a decent reliable service.

As an installer it’s my job to prtoect my clients from sharp practices in the industry, and install boilers and heating systems to be reliable and efficient. I make it my job to get things right, which calls for a degree of scepticism…especially given the way the industry in the UK has evolved,

Once again, can I ask you provide us with links to support what you have said about the disadvantages of corrosion inhibitors. Their use is well established in the UK and having seen how my own system has been protected over many years, I believe they work. My interest is mainly because I’ve spent my working life as a scientist and have been fascinated by chemistry since I was a school kid.

I like the look of the Intergas approach which has , by design, fewer parts to go wrong. Certainly seems to be very popular on the continent. Surely the massed ranks of the Consumer Associations can run some tests covering boilers, water heaters, solid fuel based systems, and the ground and air pumps.

Now that Which? is no longer spending £3m a year in India establishing a magazine that money would go a fair way towards any long term testing.

Intergas boliers don’t feature in the recent Which? report, so I assume that they are uncommon in the UK or perhaps sold under another name. I’m not sure whether to be impressed that the heat exchangers have a ten year warranty or disappointed that the rest of the components are covered for only five years.

Boiler manufacturers have responded well to the demands for more efficient products, so now it is time to push for more reliability. If manufacturers have to pay for repairs they may want competent people doing the installation and I discovered that to have a 15 year warranty on a Glow-worm boiler, it has to be installed by an approved company.

Until I read the Which? report I did not realise that boiler manufacturers are following the car industry in offering longer manufacturers’ warranty. I hope we can look forward to longer manufacturers’ warranties becoming available on a much wider range of goods. Having a boiler replaced is a fairly major exercise and I believe that they should be designed to last 20 years.

“The success of the Combi Compact ECO RF’s design has been acknowledged by the Dutch consumer association, the Consumentenbond and has been awarded the “Best Tested” accolade for two years running.”
The Dutch consumer organisation has a membership of just under 0.5m in a population of 16.5m.

but you can have reliable boilers if you follow working practices around which the boilers are designed..that is low running temperatures created by compensation controls, and no cocktail of chemicals that appear to have un intended consequences further down the line, and install a permanent quality filter.

wavelength, there is no internet information about the unintended consequences of inhibitors, But if you are in London you are welcome to join me on a site visit to resole these…

Alec – I have had a look at a recent manual for a Vaillant boiler. The following products are approved:
“Additives intended to remain permanently in the system
– Fernox F1
– Fernox F2
– Jenaqua 100
– Jenaqua 110
– Sentinel X 100
– Sentinel X 200”

It warns of the dangers of alkaline system water to aluminium heat exchangers, and that mixing products could be harmful, and that products must be used according to the manufacturer’s instructions. That’s good advice.

I suspect that the problems you refer to (‘cocktail of chemicals’) are due to use of inappropriate inhibitors (the choice is affected by the type of boiler heat exchanger, for example) or mixing products that are not compatible. To avoid problems it is probably best to stick to one brand of products for cleaning and protecting the system, and to check that they are compatible with the boiler and other components. If the products sold to protect systems were causing damage for any reason other than misuse, I think we would know about it.

Thanks for the invitation, but I’ve recently been on holiday in London and I am not planning to go back soon.

My 19 year old boiler is a Glow Worm Hideaway 40 and came with a ‘First Year Comprehensive Guarantee.’ If they are now offering a 15 year guarantee then I would certainly opt for this when my existing one dies [that is if I am able to locate a recommended installer.] Their new models come with the following recommendations:

“In the case of an existing installation it is ESSENTIAL that prior to installing the new boiler the system is thoroughly flushed. For optimum performance after installation of a new system the boiler and it’s associated CH System should also be flushed. Flushing should be carried out in accordance with BS7593 : 1992 using a cleanser such as Sentinel X300 or X400, Fernox restorer or Salamander corrosion guard cleaner.

For long term corrosion protection, after flushing, an inhibitor suitable for stainless steel exchangers should be used, refer to the current issue of BS5449 and BS7593 on the use of inhibitors in CH Systems. Examples are Sentinel x 100, Fernox protector or Salamander corrosion guard inhibitor.”

However, for a more independent overview you may be interested in the following: Are magnetic filters for central heating a good idea? @ http://www.telegraph.co.uk > Property > Renovating & DIY.

Thank you Beryl for pointing us to the various British Standards that support & actively recommend the use of reputable brands of cleaning, neutralising, & inhibiting chemicals.
Whilst we few contributors to this thread may have differing views, the unseen army of readers of these posts will have drawn their own conclusions by now.

From the article mentioned by Beryl: “Ideally, your centralheating system should not contain any sludge anyway, because it should be dosed with corrosion inhibitor. This is easy to do, but some heating engineers do not routinely install inhibitor or even check for its presence, preferring to sell magnetic filters to their customers instead.
This is worrying, because I have heard that some boiler manufacturers, when called out on warranty claims, are first testing the system water for inhibitor, and saying that if the inhibitor concentration is not adequate, then this invalidates the warranty.”

As I see it, doing what Andy says is the top priority. A magnetic trap should last indefinitely, but if it collects any significant amount of material the corrosion inhibitor isn’t doing its job.

I hope your boiler lasts as long as mine, Beryl. Mine is a Glow-worm Space Saver 50. Unfortunately is much larger than modern boilers.

so what happens if a radiator is changed and the system partially refilled diluting the inhibitor….

no doubt the installer of the boiler will get the blame…even though the builder who changed the radiator failed to top it up.

I don’t use inhibitor (I am an installer of 50- 100 boilers a year) and have every reason to think over time they give issues. I don’t have guarantee claims either…

In fact to be precise systems where I find inhibitors have been installed give more issues than those that have no inhibitor and use a permanent filter (not necessarily magnetic, but not a strainer either!).

I can think of one boiler manufacturer who stopped using sound deadening rubber hoses because they reacted with inhibitors, and a valve manufacturer where the ball/shoe expanded with inhibitors.

I can think of my installs where there are problems where I did put in inhibitors some years ago , and can recall many installs that are ramping up the years with no inhibitor, but have a strainer..

They don’t use inhibitor in Germany, but they do use particle filters (not strainers) as they do in Holland.

This industry knows how fearful the public are and come up with all sorts of half baked schemes to reassure people…

People in Holland and Germany don’t like unreliable heating systems any more than UK consumers…so in the end it has to be working practices that are causing issues not the boilers themselves…

I defer to your extensive experience but I respectfully advise you that a recommendation by The British Standards Institute [sometimes known popularly for it’s “Kitemark” brand] is not to be taken lightly. These people test to rigorous scientific & engineering standards & have many shared/equivalent standards with other European Standards Aurthorities such as the German DIN & pan European EN standards. To compare the authority & veracity of “Which” testing to BS testing would be a grave mistake.
I think I have said enough on this post now & will say no more.

Alec – Thanks for giving us a couple of examples of how inhibitors can cause problems. My view is that the compatibility of these inhibitors with system components should have been checked prior to use. I had to install no less than four motorised valves into my own system to allow proper control of the heating and hot water thanks to a very strange installation retaining a separate back boiler unit for hot water, at the previous owner’s request. I remember struggling to establish that these valves were compatible with Fernox, which was already present in the system when I bought the house.

Perhaps we should get the Conversation back on track and discuss the costs of service contracts compared with repairs when needed. Thankfully I cannot contribute to that. 😉

Is everything alright here?

No problem I can see.

The discursive discussions I find more interewsting than one limited simply to service contracts. Rather like discussing only houses from the viewpoint of the service charges, it would seem strange.

BTW why do Which? not look at what other European consumer organisations recommend if that particular brand is actually now available in the UK.

Patrick – I think it would be very useful if Which? looked into ‘power flushing’, which is an expensive process and can be very messy. My view is that proper commissioning of heating systems and correct use of corrosion inhibitors should the need for flushing.

A lot of what we have been discussing may not seem relevant to the topic we have been given but does relate to the costs of keeping our homes warm.

Perhaps Which? could also find out how common it is for people to ignore the general advice to have gas appliances checked annually. It is a legal requirement for landlords to have this done, thank goodness, but home owners are under no obligation. I have been asking around and found one person who had a condensing boiler fitted fifteen years ago and it has never been serviced or inspected.

…………Which reminds me it is due for its annual service.

Thanks for the comments guys. It is through these debates that I learn from the experts about topics that under normal circumstances it would never occur to me to investigate. If it helps people reading them to make their own choices, it is worth the time and effort. As the saying goes, “forewarned is forearmed.”

I really think one has to understand the industry I work in to make any sense of it…to most it is a warren of confusion and competing interests for a fear based sale…

I know and understand the risk I run, my business is solvent, and I understand what my clients want.

organisations like “Which” have the resources to get to the bottom of this, but I can’t see a european consumers association forming any time soon, meanwhile manufacturers push for their own interests before any one else’s, making hay while the sun shines…

Reverting back to topic, I have managed to locate the original Instructions for Use [19 years old] for my Glow Worm Hideaway boiler. Maintenance Instructions run as follows:

“To ensure the continued efficient and safe operation of the boiler it is recommended that it is checked and serviced at regular intervals. The frequency of servicing will depend upon the particular installation conditions and usage, but in general once a year should be enough.

It is the law that servicing is carried out by a competent person.

If this appliance is installed in a rented property there is a duty of care imposed on the owner of the property by the current issue of the Gas Safety [Installation and Use] Regulation, Section 35.”

The fact that the boiler continues to operate without regular servicing is surely no guarantee that it is safe.

As always with specialised debates of this kind it is interesting to hear the other side and the contrasting opinions of the professionals, which may result in veering off topic but nevertheless can often prove very enlightening.