Wiring an Evohome BDR91 to Hallway Thermostat - Which wires go where?

[Stewart Birrell]

Hello there,

I am installing my Honeywell EvoHome in our new house and it should be easy. All I need to do is replace the Hallway Thermostat (Honeywell T6360B) with the Wireless Relay box (BDR91). However, I am not sure which wires from the old thermostat go into which places in the BDR91. As shown in the photo the hallway thermostat has four wires (inc the earth) and these go into locations 1, 2 and 4. I can work out which ones go to N and L in the BDR91, but do I need a 'switching live' (i.e. a separate wire from L to A), or where does the third wire from the hallway thermostat go into?

We have an Ideal Logic Heat 30 boiler, not a combie as we have a separate hot water tank.

Any help will be super appreciated.

Cheers, Stewart

 

[stem]

these go into locations 1, 2 and 4.

Looking at your photo they go to 1, 2 & 3, which is where they should be. There isn't a wire in 4.

The terminals at the Honeywell are identified for you on the inside of the cover

So in your case:

Terminal 1 Live (Red wire)
Terminal 2 Neutral (Blue wire)
Terminal 3 Switched live (Yellow wire)

The BDR has the following connections:

You can see that they are marked N / L(1) / L(2) / A / B / C. Ignore the wiring in the photo above, it's a different system. In your case:

Red wire to L(1)
Blue wire to N
Yellow wire to B

Add a link wire between terminals L(2) and A

The BDR is double insulated so does not need an earth connection. Put the earth wire in a separate insulated connector and tuck it safely out of the way.

There are no hot water control wires at the Honeywell room thermostat, so the hot water control will remain elsewhere as it is now.

If you have an existing programmer for the central heating, that would now need to be set to be permanently 'on' 24/7 to keep the BDR91 powered.

 

[Stewart Birrell]

Great thanks for the reply, really helpful & clear.

However ... I wired it in as suggested & the BDR91 does not turn on (i.e. no lights, even when I press & hold for more than 5 secs). My multimeter says that there is 9.6 V going from N to L.

Do I assume I need more than 10 V to run the BDR91? If so what can I do to get it working.

Thanks again, Stewart

 

[stem]

I wired it in as suggested & the BDR91 does turn on (i.e. no lights, even when I press & hold for more than 5 secs).

I assume that is a typo and should say "does not turn on"?

Anyway, yes you require 230V for the BRD91

The same as the original thermostat. Although the original thermostat would work in a fashion on a lower voltage, but it's not the correct thermostat for a low voltage application. As it clearly shows a 230V L and N supply to terminals 1 & 2, and the accelerator device that improves accuracy shown connected between terminals 2 and 3 wouldn't work on a low voltage.

Did you make sure that:

If you have an existing programmer for the central heating, that would now need to be set to be permanently 'on' 24/7 to keep the BDR91 powered.

 

[Stewart Birrell]

Simple answer - no I didn't turn it to permanently on (as clearly told to). As expected it now works.

Thanks for the reminder, great help, cheers.

I'd feel even more silly if this wasn't a DIYnot forum!

Now I just need to bind & set the system up.

Thanks again.

 

[MeldrewsMate]

Now I just need to bind & set the system up.

...and put up with the regular opening and closing of the zone valves as is the way with Honeywell's crazy 'TPI' system.
Just in case, don't throw that old mechanical 'stat away just yet!

 

[stem]

As you are based in Canada, I suspect what you have written is based on the heating systems installed in North America. It doesn't really relate to heating systems in the UK. Here thermostats cannot be used as relays and 'hot wires' doesn't mean anything.... Unless you are into stealing vehicles.