DIY Doctor UK DIY Forums

Hi - believe it or not I've used my immersion heater for the first time today after moving into my new built home 7 years ago. It tripped the electrics as soon as I switched it on.

Being inquisaive I took a look at the wiring. Live, neutral and earth all run from the on / off switch. Live and neutral are connected to the thermostat (one each side - effectively creating a circuit within the thermostat). The earth is connected to the neutral terminal of the heater. The soldered connecting link (live) from the other terminal of the heater is left unconnected.

Even to me, as a non-spark, this looks completely wrong.

Two questions: 1. Should I have strong words with the builder re incompetence? 2. If I try to re-wire the thing myself, I guess it goes as follows:

Live to one side of the thermostat; connecting link from other side of thermostat to live terminal of heater; neutral to neutral terminal of heater; earth to earth terminal of the heater.

Would appreciate comments on either of my two questions. Thanks.

After 7 years you have very little come back on the builder likely the plumber wired it anyway very common where electricians have finished a house before plumbers have finished for the plumber to wire it him self.
As to immersion heater I think it may need renewing anyway! There was a problem with the older models where they had a single thermostat and if the contacts became welded on it could boil the water and soften the plastic tank in a loft to such an extent that it can collapse some young child got killed when this happened so new ones have a button reset-able over temp so if the thermostat fails the second one will switch it off.
With this in mind maybe you would want to consider changing it? The less it is used the more likely contacts are to stick and with a direct short on thermostat even more reason to check it.
See http://www.tsdr.co.uk/
Eric

Sounds like good advice. Thanks Eric.

Hi, new here but need to speak up. Please get this checked by a proper spark and take advice from him/her. It's just not worth risk of getting wrong especially if you do have kids (or the next owners of the house do!), should be more than £100 all in. Peace of mind is worth that surely?

I have noted that you can get replacement thermostats with the new protection built in. Not done any houses with immersion heaters lately except for one with steel header tank so have not needed to replace any. Not used with combi boilers.
Eric