Removing Old Thermostat

Section62

NSG666 said:

Fair points Section and probably best left alone but what else do you think it could be for? (Genuine question not trying to be clever with you)

No idea in this case. But I've seen wall stats used to control anti-frost heaters in the loft.  Ditto under suspended (ground) floors. Although there are more appropriate devices for those jobs, the proud (often DIY) installers usually have a plausible reason why they did it that way ("I only want the heater to work if the central heating fails" was one of the great ideas that had been had, there's some logic there I guess)

Old/defunct underfloor heating another possibility? Heating element in a towel rail or radiator somewhere/sometime?

There is a good chance it is related to the CH. But no way of knowing for sure without doing the right tests, which with no disrespect to the OP is beyond most DIYers, not least due to lack of the right equipment (i.e. more than a multimeter or probe).

NSG666 said:

I've seen loads of these left in situ when the CH system controls have been changed probably because the old stat is less ugly to look at than the 'gap' in the decorating if removed or they just couldn't be bothered. I guess there must be lots of incompetent installers out there.

Very common, for exactly that reason.

Once the boiler job is done and the paperwork completed it will be someone else's problem to sort out.

Jeepers_Creepers

Ben, where was the old hot cylinder? Could you have a look in there for an old wiring box, the now-empty space where an old wiring box existed, or the end of that cable...

Is the new combi in the same place the old boiler was? If so, look for ditto around there. If not, go to the old boiler location and ditto.

Section62

Ben1989 said:

All fair points. The thermostat has ZERO effect on the heating. However, I couldn't even hazard a guess where the end of this stat could be. The tanks were in the loft if that's a possible old use.

Ben, for your own safety please either get a professional in to sort this out or just leave the thermostat alone.

You'll no doubt get some well meaning advice on how you can DIY this yourself, but without the right test equipment and techniques, or lifting floorboards, there is no sure way to prove the thermostat can be safely removed. Even if you do find another end of a wire which looks the same, that doesn't discount the possibility the thermostat isn't energised from elsewhere.

Having paid out for testing for asbestos in the artex it would be more than tragic if you or a loved one now got electrocuted as a result of DIYing the thermostat.

Be safe.

FreeBear

Ben1989 said: The thermostat has ZERO effect on the heating. However, I couldn't even hazard a guess where the end of this stat could be. The tanks were in the loft if that's a possible old use.

The other end of the cable from the thermostat would have gone to a wiring box probably near the old boiler. But as with all these things, it might have been wired in elsewhere. Without an expert eye and some test equipment, there is no way of knowing for certain.

Unless you have intimate knowledge of how your house is wired up and have the experience & expertise to deal with mains voltage, leave it well alone.

NSG666

Ben1989 said:

All fair points. The thermostat has ZERO effect on the heating. However, I couldn't even hazard a guess where the end of this stat could be. The tanks were in the loft if that's a possible old use.

Ben. Apologies and ignore everything I suggested. I got a bit giddy as it's one of those jobs that I would find quite straightforward were it in my house or were I on site but I've missed out some other checks and procedures that would need to be carried out and I shouldn't be encouraging others.

Section62 - I should have known better esp as I've also come across (DIY?) wiring and thought 'why the flip did they do that'

fenwick458

It's probably dead, but to be safe test it wit a 2 pole voltage detector
if it's dead and you can find both ends and confirm that, just cut them off and thats the end of it.
if it's dead and you can't find both ends, terminate the cable safely (e.g put each core in a terminal strip and cover with insulation tape)at floor level, if it's floorboards below then push under the floor, if it's a solid floor then it'll just have to be at skirting board level