Honeywell CM921 Randomly Stops Communicating With Boiler

[boiler10]

Hi everyone, just need a bit of help please. I have an ideal logic boiler with a Honeywell CM921 room stat and I seem to be having a few problems.
I will try to explain exactly what happened today. Has happened quite a few times before.
Turned the boiler on using the Room Stat with target temp at 19 C.
House started to get really hot. Checked temperature on stat and it was well above the target temp.
Checked the boiler and the Central Heating was still running with a "C" in the display.
Took the stat upstairs, turned it on and off several times, wouldn't work. Bolier still kept on running, despite trying to turn it off using the stat.
Then, had to turn the boiler off manually using the controls on the boiler.
When the boiler was turned back on, the Room Stat & Boiler were communicating again.
Any ideas plse?

Thanks 🙂

 

[armourer]

Batterys could be on their way out?
Poor signal strength due to position of transmitter or receiver?
Or may be getting interference from other electrical equipment? (or neighbors stat lol)

Tbh I have fitted 100's of these and never had a problem with them failing easily the best on the market imo.

By the way dont forget you always have the manual override on the receiver and the green light gives you a good indication if it is receiving the signal or not.

You can get the installation guide here

http://www.honeywelluk.com/products/Systems/Wireless/CM921/

This will explain operation and reprogramming if required.

 

[SimonJohns]

Battery's

 

[armourer]

Battery's

Oh come on at least try ffs you are are supposed to be the super plumber lol. 😀

 

[boiler10]

Hi many thanks for your replies so far. Will try changing the batteries and see if thing improve. Cheers :yesnod:

 

[dontknowitall]

Pump overrun switching/thermostat failed on the boiler? Or working properly and trying to lose the excessive heat through the radiators?

 

[boiler10]

Hi, just to give you an update 2.5 years on. Initially the above fault was happening on and off. However this year, the communication loss has been occurring everyday. I have now lost count how many times the room stat/relay box has been re binded. Spoke to Honeywell customer service last week and they were very helpful. After explaining what the fault was and clarifying that I knew how to operate the room stat correctly, I have been sent a replacement CM921. As soon as the electrician has been, will send back the faulty room stat/relay box. Now that's what I call excellent customer service ! 🙂

 

[diamondgas]

That's interesting to know boiler10 ... may suggest the course of action as an alternative for the customer before I suggest replacement 🙂

 

[boiler10]

Hi, glad to be of some help. I'm pleased to say that the new replacement stat is working spot on and the heating is turning on and off as it should 🙂