Evohome BDR ON when Heating is OFF

[yiangosliv]

Hi,

I have an Evohome controller with HR92s. Today in the Morning I have switched the heating completely off (via the quick actions) but from time to time I see the BDR relay to go on and off for a couple of minutes. Any idea why this happens?

[DBMandrake]

Do you have the new wifi controller or the older (first) colour model ?

Have you been around to all HR92's manually and checked their setpoints are 5 degrees ? (which is what the OFF action sets them to) On the older model controllers the HR92 local override is not reported back to the controller, so it is possible for someone to turn up an HR92 manually thus bringing on the boiler whilst the controller still says "OFF" for all zones. That is the most likely cause.

Even on the newer controller where local overrides are reported it is possible in very specific circumstances for the same problem to occur. (but much less likely)

The "OFF" action is not a true hard and unequivocal off, it is simply a request sent to all HR92's to lower their set points to 5 degrees, and the normal scheduled set point changes are suspended. If an HR92 is locally overridden it can still call for heat from the boiler even in "OFF" mode, and this will not be indicated on the main controller when the OFF quick action is active.

Also as the set points are only being lowered to 5 degrees, frost protection is still active in all rooms - if any room nears or goes below 5 degrees the boiler will come on and that individual radiator will warm the room back up to 5 degrees to avoid burst pipes. Do you have any unused rooms that are nearing 5 degrees ?

[yiangosliv]

Hi DBMandrake

Thanks for the Reply.

I do have an HR92 in a room which is set permanently to off but the room reports a temp of 16-17 degrees.

Regarding my equipment:

I do have the oldest Wifi controller (embedded wifi) which I bought Nov 2015. My HR92s are actually HR92WE ( for horizontal installation), which i bought in Jan 2016 so I assume its new. The Version of the firmware once I switched on the HR92s was 1.01 I am not sure if that helps. So If i get it right, if i set all zones to 24C and I go on an HR92 and manually turn it to 21C (if I have the latest Honeywell components) should 21C be updated on the controller to reflect the manual changes?

[DBMandrake]

As far as I know all HR92's have firmware version 1.01 - mine all do.

The latest firmware on the wifi model is Application Software Version 01.00.02.01 and Wifi Software version 01.00.02.00.

You can check the version by going into settings then holding your finger on Device Settings for about 20 seconds. (Hidden screen)

If you have this firmware version then a manual override made at an HR92 should be reflected on the main controller screen. (Try it to see!)

It will show up as a timed override which lasts until the next set point.

Did you check all your HR92's to see if any were turned up manually ?

[yiangosliv]

I checked my Evohome firmware and its the versions you have provided above. I have set a program via quick actions for the zones and then manually changed the target temperature on the HR92s. The evohome wifi controller did not update the screen with this change in temp. Am I doing something wrong? By the way I have noticed that any temperature set as target one on the HR92s which is different than 20C, shows a circular arrow (set point) on the HR92 screen. Any idea why is that?

[Fursty Ferret]

Delete the system devices from the controller (boiler relay or hot water setup), clear the BDR91(s) by pushing and holding the button until the light blinks slowly, then repair.