Thermostat keeps switching on/off

[Deleted User]

Hello,

I've got a thermostat downstairs in the hallway and upstairs in master bedroom and once they get to the desired temperature you can hear an audible click, then boiler switches off. But then they drop 0.5c then come on, and it does this quite often. Silly question but it's forever clicking off / on and boiler off then firing up - is this by design, can I do anything to stop the frequent on / off nature?

Cheers

TELLIT01

0.5 degrees seems a slim margin, but in answer to the question yes it's normal for the stat to switch on and off. The fact that it is doing it a lot suggests the properly is poorly insulated and temperature is dropping quickly.

What I do find strange is that you have 2 stats as they will be constantly fighting each other. Normal setup is a single stat with thermostatic valves on other radiators.

phill99

As above. Why have you got two thermostats?

[Deleted User]

New build property came with one downstairs in hallway, for downstairs rads, and one upstairs in master bedroom, for upstairs rads.

EssexExile

I wish mine would do that! My house goes from too hot to too cold before the flippin' heating comes back on.

keith969

phill99 wrote: »

As above. Why have you got two thermostats?

Two separate circuits?

[Deleted User]

keith969 wrote: »

Two separate circuits?

Not sure how to check, I've looked at the consumer unit but couldn't see references to it. Is there a way to check?

southcoastrgi

Yes it will be two zones, what stats are they ?
Does it have ka watts written on the boiler ?

[Deleted User]

Danfoss 40704 stats. Boiler is a Potterton Promax Ultra Combi 33 ErP

[Deleted User]

As I understand it the clicking noise is the relay in the thermostat (+ paper thin internal wall = easy to hear), how would smart thermostats compare? If say I bought a Nest and put it on the wall in the hallway, would it be able to control both upstairs and downstairs (currently on 2 separate stats) or would wiring mean I'd need to buy two? I assume I'd need an electrician to make safe the wiring behind each stat too?

bob_a_builder

If you've got zoned heating with 2 stats, you would need 2 smart stats
But guess what they use a relay too - so still going to click !
although somewhat quieter than my previous Hortsmann 7 day stat ( with relay)

The Nest E is designed to directly replace an existing thermostat so wiring is very simple, pretty much a direct swap

Sounds like an expensive fix (if its even a fix)

Some stats (not Nest) do offer a switchable threshold - either 1/2 or 1 deg