Honeywell CM927 losing signal

[jem16]

I had this unit fitted last April.

However twice in the last few weeks I noticed the heating wasn't on. When I checked the relay box the red led was lit indicating a communication loss.

The Room thermostat has not been moved and batteries are fine. Communication test indicates the signal is being received in the position thermostat is located.

Any suggestions as to what might be wrong?

 

[Agile]

Firstly, are the batteries Duracell and how do you know they are fine?

I do have to say the reliability in service of wireless stats seems so poor that I try to avoid using them unless its the only option.

Tony

 

[jem16]

Firstly, are the batteries Duracell and how do you know they are fine?

Yes they are and I checked them using a battery tester. There is also no flashing battery symbol on display to indicate batteries need changing.

I do have to say the reliability in service of wireless stats seems so poor that I try to avoid using them unless its the only option.

Tony

I would have avoided it too but location of boiler in garage makes it very difficult.

 

[Agile]

I usually find the batteries get too low to provide a reliable transmission BEFORE the low battery symbol comes on.

Its related to the internal resistance of the battery.

Tony

 

[jem16]

I usually find the batteries get too low to provide a reliable transmission BEFORE the low battery symbol comes on.

Its related to the internal resistance of the battery.

Tony

Ok fair enough.

However as batteries tested ok I am assuming it's not that. So any other possibility?

 

[twgas]

I would put new batteries in, never assume they are good.

 

[jem16]

I would put new batteries in, never assume they are good.

I didn't just assume they were good. I tested them with a battery tester and they read the same as a brand new set of batteries.

 

[MJN]

I would put new batteries in, never assume they are good.

I didn't just assume they were good. I tested them with a battery tester and they read the same as a brand new set of batteries.

Testing a battery (by measuring its voltage) is virtually meaningless unless the battery is under load.

Try a new set. You could be right in that the batteries are fine, however a basic battery tester could well be giving misleading results.

Mathew

 

[jem16]

OK I have replaced the batteries and will monitor the situation.

I just don't want it getting past April and then thinking the relay box may have acquired a fault.