Why is my heating on when timed to be off!?

[iphonedyou]

Hi everybody.

I have a flat with a Danfoss TP9000 thermostat that's set to heat to 22 degrees for 40 mins in the morning and 40 at night. However it just completely ignores this and stays on all the time! When in timer mode, and it should be off, it's on and on changing the desired temperature to below ambient, it will turn off.

Otherwise it's just on and off, timer be damned. The hot water timing works perfectly.

Does anybody have any ideas please?

[Mandat]

iphonedyou said:

Hi everybody.

I have a flat with a Danfoss TP9000 thermostat that's set to heat to 22 degrees for 40 mins in the morning and 40 at night. However it just completely ignores this and stays on all the time! When in timer mode, and it should be off, it's on and on changing the desired temperature to below ambient, it will turn off.

Otherwise it's just on and off, timer be damned. The hot water timing works perfectly.

Does anybody have any ideas please?

Is your boiler set to constant or timer?

[iphonedyou]

Mandat said:

Is your boiler set to constant or timer?

Well that's a good question...

I have the 'heat exchanger' switch on but the cylinder switch turned off. It's a combi boiler. When I turn the heating off altogether on the thermostat it is definitely off.

This is my first place away from the parents so I'm a bit useless.

[Hoofy]

I have one of those. Replaced the original one (older model). It cocked up and wouldn't stay on. In other words, they do fail and require replacing. If you have the newest one with the round buttons, you might be able to just swap the old one out. Might!! (Note: I paid my plumber to replace mine because I'm a halfwit.)

[iphonedyou]

Hoofy said:

I have one of those. Replaced the original one (older model). It cocked up and wouldn't stay on. In other words, they do fail and require replacing. If you have the newest one with the round buttons, you might be able to just swap the old one out. Might!! (Note: I paid my plumber to replace mine because I'm a halfwit.)

Thanks Hoofy. I have the newer one, but the flat is only 18 months old so I'd be surprised if it was a failure (though you never know).

It just seems that if the temperature falls below what I want it to be when the timer is on, the heating will come on even if its timed to be off.

[elanfan]

Though you have 'times' set are there overiding settings like 'constant' on the timer - that may be your problem.

If not ebay the model number of your timer buy it and swap it over. it is really simple. Usually there is no wiring to be done as this is all in a back plate. You just unscrew the body (at the bottom) and it unclips and new one pops on to replace it. Really easy (but do isolate the power first!!

[iphonedyou]

elanfan said:

Though you have 'times' set are there overiding settings like 'constant' on the timer - that may be your problem.

If not ebay the model number of your timer buy it and swap it over. it is really simple. Usually there is no wiring to be done as this is all in a back plate. You just unscrew the body (at the bottom) and it unclips and new one pops on to replace it. Really easy (but do isolate the power first!!

Hi, thanks! I rent the place so I guess it'd be the agency would sort it but good to know its an easy fix. There is a constant option, which has the same problem - now that I say that, it seems it very well could be the unit.

Ugh.