Heating Relay switches on when controller in Off Mode and Hot Water switched on

[killa47]

I have twice spotted today that, having selected the Heating Quick Action - Off Mode, when the Hot Water timer triggers the DHW relay on, the CH relay also turned on.

This suggests to me that the controller software is not functioning correctly. If CH heating is in Off Mode, surely any command from the controller to DHW relay should only trigger the DHW relay.

This setting on the controller is not a normal setting I use - hence having just noticed this anomaly.

Has anyone else seen this situation? If not, I am wondering if there is a wiring issue. Both BDR91s are wired into the Honeywell Wiring Centre so maybe a live is feeding back from the DHW BDR91 to the CH BDR91. This I will check but if others have observed the same issue, the software needs a fix.

[DBMandrake]

Does the Green LED actually turn on for the CH BDR91 when it shouldn't ?

Are you sure you didn't accidentally bind the "CH relay" as a boiler relay on the Evotouch ?

If you have an S/Y-Plan system with only two BDR91's you should NOT have any "boiler control relay" bound.

PS I have an S-Plan system (albeit with 3x BDR91) and I don't see this problem.

[killa47]

Does the Green LED actually turn on for the CH BDR91 when it shouldn't ?

Yes, green light was on when DHW relay on. I thought I must have dreamt turning Off Mode on so checked on controller - Off mode still set.

Are you sure you didn't accidentally bind the "CH relay" as a boiler relay on the Evotouch ?

I recall that the installer set it for Heating Relay and I have checked this a few times since installed (Nov 2015) but will re-check

If you have an S/Y-Plan system with only two BDR91's you should NOT have any "boiler control relay" bound.

Correct. This is how my system is set - but will confirm this

PS I have an S-Plan system (albeit with 3x BDR91) and I don't see this problem.

Good to know. As I have not spotted this when in garage (often frequent when DIY-ing etc), I think it might have only occurred a couple of times as it would be unusual for me to set Off mode (spring-time going into summer) before switching heating sepoints to summer settings. I will check my notes but I suspect either a wiring discrepancy or software bug.

Thanks DBMandrake for quick input.

[paulockenden]

Sounds like your CH BDR91 is double bound. Did you clear the 'out of the box' binding before setting it up?

P.

[killa47]

Sounds like your CH BDR91 is double bound. Did you clear the 'out of the box' binding before setting it up?

When I ordered the kit from EvohomeShop, Richard marked the BDR91 as "Htg Relay" but I have just checked in settings and the recommended installer has set it up as Boiler Control. I did not do the device bindings, as Richard set these up for me.

So also as DBMandrake asked:

Are you sure you didn't accidentally bind the "CH relay" as a boiler relay on the Evotouch ?

It looks like I need to change it to Heating Relay as originally indicated by Richard.

Will now investigate further.

Thanks Paul.

[bruce_miranda]

Best to clear all the BDR bindings first before you bind everything back as required.

[killa47]

Best to clear all the BDR bindings first before you bind everything back as required.

Thanks for the recommendation. I have cleared the Boiler relay and selected "None" for the boiler control but I could not get the relay to stop flashing the usual variety of timed red lights.
I concluded I might have to reset the Guided Zone Configuration to switch the heating configuration and so, to avoid a Sunday conflict with SWMBO, I have temporarily re-selected the relay as Boiler Control until I figure out how to minimally reconfigure. This because the guided configuration will clear zone settings.

Does anybody agree I would have to go back through the Zone Configuration or is there a short-cut to allow the BDR91 to be a) unbound and stop flashing the binding light without b) preventing the relay to function as Heating relay.

[DBMandrake]

Don't use the guided configuration.

Just use manual configuration to remove the boiler control relay then go into stored hot water, set it to none then go back into stored hot water to rebind both relays. At worst you'll only need to redo your hot water schedule and temperature. You won't have to redo your heating zones.

[killa47]

Don't use the guided configuration.

Just use manual configuration to remove the boiler control relay then go into stored hot water, set it to none then go back into stored hot water to rebind both relays. At worst you'll only need to redo your hot water schedule and temperature. You won't have to redo your heating zones.

Ah cheers DBMandrake. That looks like a life saver. I had visions of a reset for all 12 zones plus system.

[killa47]

As DBMandrake said, removed Boiler Control, then cancelled Stored Hot Water, then re-input and bound Stored Hot Water (first the CS92 Sensor, then DHW Relay, then Heating Relay).

Took a couple of goes because un-binding and re-binding always seems a bit hit-and-miss getting the flashing red/green lights and timing correct. Otherwise, you finish up in no-man's land!.

But all done. Thanks everybody, as always - appreciated.