Salus RT500 issue please help

[annachy]

thanks mcmoby69 and alan 999, I'm not the OP and apologies I mistakenly thought it said 'BC' in the title. I'm trying to work out why I don't get any LED light at all on the boiler control unit either when the boiler fires or when I try to sync. Any advice you have would be much appreciated

Details of everything I've done are in this thread //www.diynot.com/diy/threads/salus-rt500bc-thermostat-installation.468248/

 

[annachy]

did you push the little button with a ballpoint pen on the receiver?

Yes, I've tried pushing the control unit sync button first and then the thermostat's reset button (as advised in the manual) and I've tried both at the same time

 

[mcmoby69]

You should have 4 wires into the receiver. Live and neutral supply the power, then the 2 switch wires from the boiler.

I know the external salus receivers can need a bit of care when inserting cables.
Double check them.

 

[annachy]

Yes I did notice on one of the occasions I wired the unit up (I've done it and re-done it several times) that the connections weren't sitting completely home so I've been very careful since to ensure they all are

So I have a red wire which was connected into slot 1 on the old timer which I presume is neutral so this has gone into slot 1 on the new control unit
Then two black cables that are linked together by another short black cable that were sitting in slots 2 and 3 (and why I have assumed the red cable is neutral, not live) so these have gone into the same slots on the new unit
Then a grey cable which was in slot 5 (NC) on the old timer which has gone into slot 4 (NO) on the new unit

I have tried switching the red and black cables in slots 1 and 2 just in case I got live and neutral mixed up (the wiring diagram I found for the old timer isn't helpful and doesn't state with terminal is live and which neatural although I would have assumed the new unit would mirror the unit it's replacing) but to no avail

I'm really stumped

 

[mcmoby69]

You can't assume or presume anything.
You need to start over. Identify live and neutral to power the receiver. To test the receiver is working you could wire it up with a plug.
Once you've ruled out a faulty receiver. Then you can sort the switch wires, polarity doesn't normally make a difference.

Personally I think it's pilot error. (You)
But, I'm not in front of the boiler.

 

[annachy]

I'm perfectly happy to accept it's likely my error which is why I'm here looking for help and advice. OK thank you, that's helped further my understanding of some of the basics. I'm still utterly perplexed because when I wire the unit up to a plug as suggested I get a light and when I wire up the old timer to the boiler it works as expected but when I wire up the new unit to the boiler, no matter which of the possible pairs of wires I connect to the live and neutral terminals and no matter how tight I clamp the connections closed, I get no light