Central heating thermostat
Author
Discussion

Ray Singh

Original Poster:

3,056 posts

246 months

Saturday 24th October 2009
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My central heating room thermostat looks to have given up.
Im not technical so bear with me.

Ive got one of these:



When i turn it, it seems like the rotary part is not connected to anything. It now doesnt click to turn on/off the boiler.

Ive found a suitable replacment from Plumbworld, but noticed that the current 'stat' is mains.

Now taking this as a chance to upgrade - can i replace it with anything else?

Plumbworld has the following:




or



jeebus

445 posts

200 months

Saturday 24th October 2009
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You can use the second one with no problem not too sure about the first as it looks more like a programmer to me.

Smiler.

11,752 posts

246 months

Saturday 24th October 2009
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The plastic dial on mine (same model) had cracked. I glued the crack, but the split opened when I pushed the dial onto the metal spline (which is the bit that turns to make the contact).

I glued the crack again & added some small plastic strips on the inside. I applied a rubber band around the outside t apply pressure.

Worked a treat.

The dial types are usually 2-wire (+ earth), I think digital ones might need a neutral.



Deva Link

26,934 posts

261 months

Saturday 24th October 2009
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Smiler. said:
The dial types are usually 2-wire (+ earth), I think digital ones might need a neutral.
The digital ones DON'T need a neutral - as they're generally battery operated.

The contacts inside are voltage free - so you wire the live and switched live across them. It could be they're the only two wires (perhaps plus earth) in the old stat anyway - the neutral is just there to provide a return for the accelerator heater, and it's not unusual to find the heater isn't wired in anyway.

Ferg

15,242 posts

273 months

Saturday 24th October 2009
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Smiler. said:
The dial types are usually 2-wire (+ earth), I think digital ones might need a neutral.
Most dial type stats will have an anticipator circuit and therefore a neutral. Digital stats are very unlikely to.
If an aneroid (dial type) stat has no neutral it's because the sparky was too lazy or only put enough cores in for the switch wires.. smile

Ray Singh

Original Poster:

3,056 posts

246 months

Sunday 25th October 2009
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Update - for those of you that responded.

The original thermostat gave up completly this morning. I the rotating dial wasnt making contact with anything at all behind and hence the heating was stuck at full blast or nothing at all.

Screwfix came up trumps with a replacement exaclty the same as the original for £19.99. I remembered to swith the boiler and mains electricity off and took the old unit of. Sure enough, the plastic spindle was in pieces.

Took some pictures of the wiring and took the old unit off completly. New unit wired up and installed within 1 hour.

Thanks for your responses. I appreciate it.