Thermostat keeps switching on/off

[Deleted User]

Cheers. I used to have a Hive where I lived previously and I've honestly never heard it once. It was a detachable unit from the wall which I guess linked to something connected to the boiler / router. As far as I can recall this replaced an old style stat too. I've since bought a new build home so feel smart heating would be a nice addition (and maybe quieter too), it's just I'm not sure what's the best to go for.

coffeehound

Assuming the 'stats are TP4000 series, it should be possible to switch between chrono-proportional, and simple on-off control.

Perhaps it is the chrono-proportioal mode that is causing the frequent switching, and they would calm down if changed to simple on-off mode?

RelievedSheff

I'm surprised that the themostats are clicking in that often.

We are also in a new build with dual zone controls and neither themostat (Danfoss) click in and out often. Once the zone is up to temperature it is usually a fair while before it clicks back in again to call for heat. In fact our master bedroom zone rarely asks for heat at all yet!

Does your house take a long time to reach the desired temperature?

[Deleted User]

coffeehound wrote: »

Assuming the 'stats are TP4000 series, it should be possible to switch between chrono-proportional, and simple on-off control.

Perhaps it is the chrono-proportioal mode that is causing the frequent switching, and they would calm down if changed to simple on-off mode?

Sounds promosing. I've read over the manual though and can't spot this setting, any ideas how I could switch between the two modes?

http://www.free-instruction-manuals.com/pdf/pa_458253.pdf

RelievedSheff wrote: »

I'm surprised that the themostats are clicking in that often.

We are also in a new build with dual zone controls and neither themostat (Danfoss) click in and out often. Once the zone is up to temperature it is usually a fair while before it clicks back in again to call for heat. In fact our master bedroom zone rarely asks for heat at all yet!

Does your house take a long time to reach the desired temperature?

I'm not sure to be honest, would need to watch it tonight, see how long it takes. I suppose the stat is in the hallway where there's a very small window with a closed trickle vent, maybe the influx of air outside is cooling this area more than yours I guess.

[Deleted User]

coffeehound wrote: »

Assuming the 'stats are TP4000 series, it should be possible to switch between chrono-proportional, and simple on-off control.

Perhaps it is the chrono-proportioal mode that is causing the frequent switching, and they would calm down if changed to simple on-off mode?

Really appreciate this reply. I didn't realise this was an option, never heard of it. I've phoned Danfoss and he agreed and explained that chrono-proportional keeps the temperature in and around the desired number and keeps the temp steady by switching on / off. Switching to on-off mode means it'll aim for 1c above the desired temp, then turn off, then come on again when it drops to 1c below the desired temp.

Danfoss engineer walked me through changing modes and if anyone comes across this in the future then the steps are:

Hold down prog and down arrow for 5
Hold down prog and up and down arrows for 5
Press + until smaller 30 says 34
Bigger number will say 6
Press down arrow until bigger number goes to 0
Hold prog for 5 to save

Pressing the reset button is a 'soft' reset so wouldn't reverse the above. You'd need to do the above again and put the number back to 6.

The above is explained in more detail on page 9 here: https://assets.danfoss.com/documents/DOC041186407154/DOC041186407154.pdf
"Entering Installer Advanced Programming Mode"

Certainly a cheaper option than 2 new smart thermostats

coffeehound

Ah that's good. Be interesting to see how you find the 2 degree deadband. If it proves to be too big, then number 3 in Option 34 would be another one to try. That apparently limits each thermostat to three cycles per hour in Chrono-Proportional mode, where before you had six per hour as the default setting.

.

shortcrust

EssexExile wrote: »

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

Oh I’d love separate thermostats for upstairs and downstairs!

I have Hive heating and they’ve recently changed the way the thermostat works. You get much shorter but more frequent bursts of heating which means you don’t get as much temperature overshoot and the room temp stays much closer to the target temperature. It sounds to me like your heating works in the same way whereas others who have long gaps between the boiler firing up probably have much greater temperature swings. Obviously when looking at different homes other factors like boiler temperature, radiator size and insulation would also affect the interval between heating. Anyway, the reason I mention that is to point out that neither method is right or wrong. Just different.

RelievedSheff

shortcrust wrote: »

Oh I’d love separate thermostats for upstairs and downstairs!

It isn't all it is cracked up to be. Ours is set up so that the master bedroom and en suite are on one circuit and the remaining two bedrooms are on the same circuit as downstairs.

Whilst it is nice to be able to keep the master bedroom cooler than the rest of the house it does also mean that it is a bit chilly when we get out of the shower in the en suite.

We just control the temperature in the other two bedrooms with the TRV's.