Wiring a thermostat to a combi boiler

[trev77]

Hi All,

I have a Vaillant TurboMax Plus combi boiler to which I intend to connect a Salus RT310RF thermostat, hopefully without frying the PCB.

Just looking for confirmation that this is the way to do it..

1. Switch off power supply to boiler.

2. Wire up thermostat with 3-core-and-earth 1mm cable where brown=Live, grey=Neutral, and black=Switch Live to L, N and NO respectively.

3. Take the red loop wire currently connecting 4 and 5 on the boiler and use it to link L and COM on the thermostat.

4. Wire up the 3-core-and-earth to the boiler with brown to 3, black (sleeved brown) to 4, and grey (sleeved blue) to 5. Cut back the earth.

Does that sound about right?

 

[Deleted member 267285]

I don’t follow what you‘ve said exactly, leave the boiler LNE connected, the loop is between 3 and 4, so yes remove this, use 3 to L on Salus, 4 to NO, 5 to N on Salus, and link L to Com. Careful though, as opening up some boilers require critical safety checks afterwards.

 

[Londoner2]

Get this instead; Salus RT310i so u can control from anywhere.

 

[ianmcd]

you are massively over complicating things L&N to L&N on the Salus
remove link and one terminal to NO and the other to Com either way round it doesnt matter

 

[ianmcd]

use 3 to L on Salus

If he does that mate when the boiler is selected to off or HW only the salus wont get power, the Salus needs a permanent live

 

[ianmcd]

Get this instead; Salus RT310i so u can control from anywhere.

Or better still get anything other than a Salus

 

[Deleted member 267285]

If he does that mate when the boiler is selected to off or HW only the salus wont get power, the Salus needs a permanent live

Ahh, gotcha. Thanks mate, was thinking it was similar to EcoTEC pro, which you can’t select hot water only. 3 on them is permanent live, unless you turn the boiler off at front switch.

 

[trev77]

Thanks for the replies, and to clarify, Ian, are you saying I need a 4-core-and-earth cable, doubling up the existing boiler Live and Neutral terminals with the L and N from this new cable, and using whatever 2 wires that are left to replace the loop currently connecting 3 and 4 on the boiler?

So 5 on the boiler would be unused, and I wouldn't need to loop L to COM on the Salus?

Thanks

Trev

 

[ianmcd]

Thanks for the replies, and to clarify, Ian, are you saying I need a 4-core-and-earth cable, doubling up the existing boiler Live and Neutral terminals with the L and N from this new cable, and using whatever 2 wires that are left to replace the loop currently connecting 3 and 4 on the boiler?

So 5 on the boiler would be unused, and I wouldn't need to loop L to COM on the Salus?

Thanks

Trev

use 4 core and wire as I suggested no links required, you can do it with 3 core and use the earth as a switched live and sheath it, then you would need a link, best you do it properly

 

[trev77]

Wired up as Ian suggested, Live and Neutral in with the existing L & N, and replaced the red loop between 3 & 4 on the boiler with grey and black from the COM and NO terminals on the thermostat. All working a treat. Thanks, Ian.

Trev