need to replace thermostat help

baza455 said:

Hi, cm921 honeywell thermostat is old and need a new one so i ordered a new replacement (picture below). This new one i bought which is coming tomorrow has a receiver not sure if I have to wire it up but I assume i have to, its hannicks brand but ill see if it can pair with honeywell maybe it does idk, so I was thinking if I won't be needing the wired honeywell receiver at the boiler I can just make sure theres no voltage running through it by turning off cb and testing with my fluke pen (i know I will be buying a 2 pole voltage and cont' tester soon) and replace it with the new one?


also if I had to isolate the honeywell receiver, Do i need to trail the wires back into the boiler and disconnect them? or just tape off the ends

I will drop some pictures below

[Valiant boiler]

View attachment 118347View attachment 118348View attachment 118346

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PS Electrics said:

If that is a R6660D relay box in the picture (it looks like one) then the product description says it works with that and you will only need to pair it.

Video on the product page explains how to do this.

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baza455 said:

so i got the kit, haven't installed yet but I assume I will have to make a hole in the wall for the wires to come through the backbox? the previous honeywell above has them coming from underneath. or can i make a hole at the bottom of this backbox(I don't think it's ideal on this?)

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PS Electrics said:

I didn't think you was going to replace the relay box? You shouldn't need to as the unit you purchased will work with that relay box providing as I said above the relay box you have is one that is listed on the product page as compatible, unless of course that is faulty?

I would consult the installation instructions that came with the product, that should show cable entry points to use as well as a wiring diagram.

If you are going to replace the relay box then please follow safe isolation procedures and a fluke pen is not considered adequate for safe isolation purposes. Wait until you have the correct equipment which ideally should be a voltage tester with a proving unit.

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