wireless room thermostat

[collygirl]

Help please

My daughter has a Honeywell wireless room thermostat cm921 and the unit seems to be showing the wrong temperature. This is making the central heating come on even when the control is set to off.

She has just moved into the house and this is the first winter she has used it. We have looked at the instruction book but it doesn't say anything about what to do if the unit is showing the wrong temp. There is a 'frost stat' set at 5 but the room temp digital reading keeps showing 5.5 or 6 and we know it is at least 18 in the room.
Has anyone any ideas before we call in the professionals??
Thanks a lot

 

[Dan Robinson]

Are you sure it is the room temp being displayed and not he target temperature?

Unusual for these to fail like that but not impossible. By yourself a replacement and follow the instructions in the box for how to get the new remote unit to talk to the receiver box.

easy peasy.

 

[collygirl]

Thanks Dan for your reply, it is definately showing room temperature wording. Is there no alternative to buying a new one?

 

[Dan Robinson]

No, these are sealed units, but like I said, it is easy to do - just follow the instructions for binding/rebinding.

 

[mikely]

Have you tried removing then replacing the batteries?

 

[D_Hailsham]

Do you have the Installation Instructions? If not, they are Here.

First, change the batteries - use good quality ones, e g Duracell.

If that doesn't cure the problem, reset the CM921 to Factory defaults by changing parameter 19:FS to 1.

If you still get the same result, the CM921 is faulty.

It the problem goes away, you will have to re-program all the times and temperatures.

 

[collygirl]

Thanks to all of the above . I'll try the suggestions when I next go over to her place.