Downlight above shower

1 Nov 2006
Reaction score
United Kingdom
I'm in a relatively newly built flat (less than a year old) and I've had quite a few lightbulbs blow in that time. I actually started a thread about it a few months ago which led me to getting Scottish Power to fix an over-supply problem (I was measuring the incoming supply using my UPS and it was averaging anything between 245v and 260v). Scottish Power eventually, after a lot of complaining on my part, got it down to between 240v and 250v which, although is still what I would call high, is now 'within tolerance' so nothing more will be done in the immediate future (apparently, to get the voltage down to nearer 230v would require a new local transformer to replace the currently over-subscribed one that I'm on, which they've estimated won't happen for at least 3 years!).

So, anyway, now that the voltage has been 'within tolerance' for a couple of months, I'm going round making a shopping list of all the bulbs that need replaced before I go out and replace them (the theory being that there was no point replacing them whilst I still had over-supply problems in case they blew again).

So, I knew the halogen downlighters in the flat (of which there are over a dozen in various rooms) were low voltage type, so they'd also have transformers. One such light is above the shower unit in the en-suite. I tried swapping a bulb from a working downlighter into it but it didn't work, so I had to remove the whole unit from the ceiling to take out the transformer too. I'm slightly concerned by what I found... see this link: downlight

My knowledge of electrics stretches to knowing not to do anything without flicking the switch at the fusebox, but that's about it. So, having seen the state of the light fitting and transformer, it makes me wonder:

1) It's a 35W rating on the black casing, but a 50W bulb installed. How 'bad' is this? A simple faux pas by the builder, or a serious fire risk? I've got loads of these lights throughout the flat, and they all look the same brightness to me so I'm guessing they're all 50W bulbs... potentially they're all in these 35W rated casings.

2) I didn't think you could use halogen downlights near loft style insulation but it seems that's what the yellow material stuck to the wires is. Assuming it wasn't like this when it was fitted, it means there was indeed loft insulation in close proximity. Should I be worried? Presumably a 50W bulb produces more heat than a 35W one that the black casing states, so if it's heat that's caused the insulation to stick to the wires/terminal block this is even more serious, yes? Could it also explain the warped transformer casing?

3) Any ideas what all that brown, brittle gunk is inside the terminal block? The light is above a shower unit so the first thing I thought was rust, although it's not really rust-like, it's more brown than orange. It's not like the shower fires water onto the ceiling, but it does get steamy even with the extractor fan on so I guess moisture could make it's way in there? Even so, the black casing has IP65 on it which I understand means it's safe for installation above a shower (which, in my simple mind, means that it shouldn't be prone to moisture problems).

This whole thing has got me thinking about whether or not I should be replacing it with another halogen bulb/transformer or looking at some other technology. I'm aware there's also LED and CFL lighting in pretty much similar physical dimensions these days (so I can use the hole already in the ceiling, which is sort of important). Both seem to have their pros (use less energy and don't run hot), but also their downsides (poorer light from LEDs or slow start up time for CFLs). My requirements are probably similar to most people: should provide decent light (something similar to a 50W halogen bulb), not take 5 minutes to get to full brightness, be safe for use above a shower and, if possible, not use loads of energy. As an end user, I couldn't care whether they're 12v or 240v unless there's a good argument to go one way or the other. Am I asking too much? What are being installed in houses these days? Any pointers to products I could buy online would be a bonus.

Thanks in advance,
Sponsored Links
1. 50W instead of the maximum 35W will cause the fitting to overheat.
2. Halogen downlights covered with insulation will overheat, even if the correct lamp is fitted.
3. The brown substance is rust. Evidently the terminals are not sealed against moisture, either due to a loose cover or poor design. Although the fitting is IP65 rated, the terminal box might not be.

The transformer is rated to 60W, however covering it in insulation could cause overheating and melting of the case as in the picture.

As you have other fittings, check all of them. Overheating can cause a fire, and even if it doesn't, the lamps and fittings won't last long.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links