The Efficient Home Forum

Hello,

We have a multi-zone evohome set up which has been working fine for the past couple of years. Until this weekend, when I noticed that zone controlling radiators (other zones are UFCH zones) was on despite the evohome controller showing the temperature on the Y87RF room stats was greater than the target temperature. The evohome controller seems to be recording the correct temperature wirelessly from the various Y87RF room stats, but despite the room stat temperature exceeding the target temperature for that zone, the green light is showing on the BDR91 and the boiler is firing non-stop.

If anyone has any suggestions on how to get the BDR91 to follow the programmed temperatures that information would be much appreciated.

How much above set temp are we talking?

The 'control bandwidth' which is used to accurately control the air temperature in the room factory set at 1.5 degrees C either side of setpoint for TPI control (BDR91 wireless relay box) and 1 degrees C for OpenTherm control (R8810 OpenTherm Bridge).

So for a BDR91 controlled system, the thermostat temp could be 1.5 degrees over the setpoint before the relay will be 100% off. Remember the system isn't trying to get the room up to temp and then shut off, it is trying to maintain your setpoint.

If you are fully aware of the information I have given and this is something new or odd, try turning the BDR91 off from the main power supply for a few minutes and then back on... This may cure your problem.

Thanks for your reply. A good 3 or 4'c. We had our boiler serviced today and I mentioned it to the engineer - I think he wiped & rebound the wireless stat to the relay and it seems to have reverted to normal now. Not sure what that happened but at least it's fixed now.

Thanks again for your help.