Wireless thermostat (Honeywell THR872CUK) losing connection to boiler

boots_babe

Hi,

We moved into a new house 2 weeks ago, the heating was all working just fine. But in the last few days the wireless thermostat (Honeywell THR872CUK) keeps losing connection to the boiler When it does this, the heating stays permanently on. We've following the instructions in the manual to resync the thermostat via the relay button, to the boiler. Sometimes this works, often it doesn't though.

We have tried leaving the wireless thermostat right next to the relay, which itself is only a couple of feet away from the boiler.

But each time we eventually do get it to work, it will lose connectivity again after no more than a day. I've looked online but cannot find anyone else with this exact model and problem. Are there any experts out there who can advise what else we can try - over and above the resync process that is in the manual?

Many thanks.

frogglet

Have you tried changing the battery?
We also managed to change the settings, fiddling around with it.

Jeepers_Creepers

If you haven't already tried this, worth doing:

"In case of difficulty (re-binding procedure) If you must replace a wireless thermostat or relay box, the system may not work properly afterward. Follow the steps below to re-establish wireless communication.

1 Hold thermostat about 1 or 2 metres from the relay box, then press and hold the relay box button for 15 seconds. Note: After 5 seconds the red light flashing pattern will change, but you must hold down the button for at least 15 seconds.

2 Release the relay box button, then press and hold it again for 5 seconds, until the red light flashes evenly (“binding” mode).

3 Release the relay box button, then press the thermostat OFFbutton.

4 Press and hold the thermostat p, q and < buttons until CONTROL BINDING appears on the display screen.

5 Press the thermostat OK button to signal the relay box. The red light on the relay box should turn off. If not, wait a few seconds, then press OK again.

6 Relocate and test the thermostat, as shown on page 24 of manual.

https://manualsbrain.com/en/manuals/1092736/download/

daveyjp

Agree with a battery change as IIRC there is no low battery warning.

The readout can work long after the battery can send a strong signal.

boots_babe

Jeepers_Creepers said:

If you haven't already tried this, worth doing:

"In case of difficulty (re-binding procedure) If you must replace a wireless thermostat or relay box, the system may not work properly afterward. Follow the steps below to re-establish wireless communication.

1 Hold thermostat about 1 or 2 metres from the relay box, then press and hold the relay box button for 15 seconds. Note: After 5 seconds the red light flashing pattern will change, but you must hold down the button for at least 15 seconds.

2 Release the relay box button, then press and hold it again for 5 seconds, until the red light flashes evenly (“binding” mode).

3 Release the relay box button, then press the thermostat OFFbutton.

4 Press and hold the thermostat p, q and < buttons until CONTROL BINDING appears on the display screen.

5 Press the thermostat OK button to signal the relay box. The red light on the relay box should turn off. If not, wait a few seconds, then press OK again.

6 Relocate and test the thermostat, as shown on page 24 of manual.

https://manualsbrain.com/en/manuals/1092736/download/

Thanks for looking this up, but that's the resync process we've already been trying unfortunately. 

boots_babe

Sorry should have said, we have already tried changing the batteries in case that was the issue. 

Jeepers_Creepers

In that case, try emailing/phoning Honeywell - these companies are usually surprisingly good at giving helpful answers. If you email, outline what you've already tried.

I wonder if a neighb has installed a similar system, and you are getting interference?! That used to be the case with early-generation wireless stats, but I suspect they've nailed that problem since.

Please come back with the result :-)

boots_babe

Thanks, that's a good suggestion which I wouldn't have thought of to be honest. I will give Honeywell a try. Definitely no neighbour interference, we just have fields all around us, no houses within sight.

I will let you know if we have any joy with calling them.

getmore4less

What new wireless kit have you set up since moving in?

boots_babe

Just to report back, we did call Honeywell, but everything they suggested we checked/tried, we had already done. In the end they said we'll need to get an engineer out. We're just waiting until next week when we're post Christmas/New Year and then will find someone to come out to it.

getmore4less - the only wireless type kit we have installed is our wifi. We set this up on the day we moved in, and the boiler was working fine at that point. It worked ok for over a week before it started having issues, can't think of anything that changed around the time of the fault starting.

missile

I would invest in new thermostat. I use hive, they are cheap as chips and easy to install and operate.  :-)