What should Which? test this Christmas?

Crusader — I agree it would be a good idea for Which? to test exterior floodlights, but there are so many on the market it might be an enormous exercise. They also come and go in short succession as brands and designs change within the multitude of suppliers. This is a problem with so many small electrical appliances these days.

B&Q are responsible for the safety of the products they sell and if only the purchaser had returned it to the retailer it might have led to the product being withdrawn but, unfortunately, there is no guarantee they would have done so or would even have examined the floodlight. It is only because you took the fitting apart that it was possible to see that it was not earthed. There is the possibility that the unit bought by your friend was an individual defective example and good practice would have ensured other samples were examined.

I would recommend anyone installing an exterior floodlight to employ a Part P-qualified electrician. Hopefully that would ensure the correct form of circuit protection was in place for the fitting.

I put up two bright rechargeable solar floodlights with PIR movement sensors for a friend a couple of years ago and they are still working fine. They seem well made, unlike some of the cheap products available and have the advantage of needing no mains supply. The drawback is that they need to be mounted where the solar panel has reasonable exposure to sunlight.

Having seen videos showing mains-powered floodlights with poor or non-existent earth connections I would be very wary.

B&Q provide a list of product recalls and safety notices on the homepage of their website – something other companies could emulate.

In the past, Which? have reported finding unsafe examples of products during testing, so I hope that they do routinely check the safety of products they test.

Water ingress into exterior lighting is not necessarily due to a defect in the product and may be caused by poor installation. It’s worth inspecting exterior lights for condensation because this could identify a forthcoming problem.

My son bought some electric panel heaters from Screwfix (Kingfisher) with no earth and marked Class 2. The housing was painted steel, the incoming terminal block was close to the housing and single insulated wires. Were a wire to come adrift it could have contacted the casing. I see no way they could be Class 2. They were exchanged for another make that was earthed.

This was reported to Kingfisher. I have just been reminded by Em’s post that my son never had the promised response from Kingfisher. I must ask him to follow it up and, if necessary, involve Trading Standards; he did photograph the electrical arrangement.

Keeping an exterior light free from water requires careful design. If, for example, water can lie on the seal of a part removed for wiring, or on the cable gland seal ( that may not be correctly assembled after wiring) it can be drawn into the light simply by the slight difference in pressure between inside and outside caused when it cools after switching off by the heat from the light source, or cooling after a sunny day.

We used to demonstrate the partial vacuum created by chilling, with cold water, a sealed light after it had reached operating temperature then switched off. The clear cover on the underside could simply not be opened, and even a modest pressure difference could allow a 50kg weight to be hung from the cover. Any slight pinhole gap in the gasket would allow any lying water to be sucked in.

I have seen some horrors such as two cables through a gland and light fixtures upside down, with the cable entry at the top rather than the bottom. Thankfully rain water is not very conductive.

It’s amazing how much water can ingress by capillary action through a narrow gap if the seal has deteriorated or been damaged. Some of the modern floodlight designs do not look very robust even when brand new. I have noticed that many installations also have the luminaire set at an unsatisfactory angle. Apart from causing nuisance light spread this can compromise the watertight properties of the fitting.