Replacing Danfoss RX-1 with Honeywell BDR91 to Worcester Bosch Greenstar

[dee-aye-why]

Hi folks,

Thanks for taking a look here.

We have a Worcester Bosch Greenstar 30CDi Combi boiler, and a Danfoss RX-1 unit as relay to it.

Existing Wiring:

From what I can work out from the wiring guides for the Honeywell BDR91 and the Greenstar, I need to do the following:

I believe I've got that right, however unsure what to do with the earth wire(s) - these are currently connected to a terminal in the corner of the RX-1's mounting plate, do I:

a) Connect them each to their own separate terminal block to terminate;

b) Connect them to the same terminal block, joining them;

c) Fit a back box for the BDR-91 that has a terminal connection for earth, and connect them to that;

d) None of the above (please advise!)

Any glaring errors? I'd be really glad of your help.


Docs:

RX-1 Wiring Diagram - http://assistyou.danfoss.co.uk/PCMPDF/RX1.pdf

Greenstar Wiring Diagram to controller is page 49 of https://www.worcester-bosch.co.uk/files/troubleshoot/gas_wiring-guide_smaller_3.pdf

BDR91 Wiring Diagram is page 4 of http://www.honeywelluk.com/Documents/Installation-Guide/pdf/bdr91-instal-50034510-uk07r1009.pdf

Thanks!

 

[Dan Robinson]

It's fine.

 

[dee-aye-why]

It's fine.

Thanks - any thoughts on the earth wires?

 

[Dan Robinson]

All cables need to be earthed even if the appliance at the end is double insulated.

 

[dee-aye-why]

All cables need to be earthed even if the appliance at the end is double insulated.

Sure. Call me thick, but which of the options in my post should I be using to do that? Connect the earths together, or to a back box, or?

 

[Dan Robinson]

Tricky from your drawing, but assuming the bdr is betwixt boiler and fcu, the just join the earth's with a butt connector in the bdr.

 

[dee-aye-why]

Tricky from your drawing, but assuming the bdr is betwixt boiler and fcu, the just join the earth's with a butt connector in the bdr.

Thanks, appreciate it. I'll choc block them together in the back box.

 

[Dan Robinson]

Do not use a metal back box.

 

[dee-aye-why]

Do not use a metal back box.

Roger that. Plastic all the way. Gonna use a faceplate for a neater mount like this geezer too.

 

[Dan Robinson]

Hhhmmmm. Some at Honeywell have had many giggles over that person's video.

A text book example of how not to install honeywell products.

I am confident his last comment is a direct result of Honeywell contacting him.

 

[dee-aye-why]

Hhhmmmm. Some at Honeywell have had many giggles over that person's video.

A text book example of how not to install honeywell products.

I am confident his last comment is a direct result of Honeywell contacting him.

Heh. You reckon it would fit reasonably flush to the existing pattress then?

 

[Dan Robinson]

Should be OK, although, tbf using those cover plates does help if you do have an annoying gap.

 

[Tony Sand]

Hi,

Did you get Honeywell evohome up and working with your Worcester Bosch Greenstar boiler? I am looking at doing something similar but I am reading that they might not be compatible and that Opentherm wouldn't work.

Any guidance is much appreciated!

Cheers,
Tony