Is my Honeywell CMT921 thermostat broken??

[gatt4950]

Hi All,

My honeywell CMT921 has been showing Room Temperature as 38 degrees since the weekend. Its very odd, just suddenly happened on Saturday at some point. I went to check why the heating wasn't on and saw the room temperature showing as 40 degrees! Its definitely not 40 degrees, and clearly the room temperature will never reach 41 to actually trigger the heating to come on as its about 8 degrees outside!

Has anyone else come across this?

I have tried taking the batteries out and leaving it overnight. It still showed 38 degrees when I switched it back on. I have also tried testing the honeywell with the relay to check its working. The relay and boiler are working fine as we have hot water and can manually switch on the heating with the relay but this is not ideal.

Any help would be much appreciated as it is cold outside!

Why do these things always happen just before Christmas...

 

[Gas2Air]

Where have you kept it? Definitely duff.

 

[gatt4950]

its just been on our side table - not near a radiator nor direct heat.

So I suppose I just buy a new one and install it. Does anyone know if I'll need to reinstall the relay box?

 

[Gas2Air]

You will need to link it to the receiver, instructions will come with the new one, fairly straight forward, but long winded to type.

 

[gatt4950]

ok...thank you....great, an unexpected £180 down the drain....

Cheers

 

[gatt4950]

actually my last try before I give up and part with £180 for a new one.... is there a reset button on these gadgets?? I can't find on anywhere and not one behind the batteries either...

If anyone knows please let me know!

Thanks for your help.

 

[gatt4950]

Ok I have had some progress (I think) - on the digital screen, it is now showing 'INTERNAL ERROR' with a picture of a spanner flashing.

Any ideas??

 

[engineerman]

£180?
it is what it is
try getting an engineer to do it as it might be cheaper, i only pay around £100 for a cm 921
he will also rebind it correctly

 

[ALEC1]

Why is it money down the drain to have a working thermostat, do you object to being comfortable?

 

[gatt4950]

thanks for your helpful response engineerman

I will speak to my local guy!

Cheers!

 

[D_Hailsham]

I would also Contact Honeywell. They have a good reputation for replacing faulty items free of charge, even when out of warranty.

 

[gas112]

http://www.screwfix.com/p/honeywell-cmt921-wireless-room-thermostat/87377


£118