Nest e thermostat for Vekera Maxim Combi boiler

[Alex Joyce]

Hi, I am looking for some advice. I bought a Nest e Thermostat to replace the wireless programmable thermostat on my Vekera Maxim 29 boiler but I am not sure of the wire connections. The Vekera thermostat has L and N then two black wires connected to CN4 and the other to the adjoining block but there is no label
on it? Also not sure of the Heat Link connections either which are C, NO, FP and then OT1 and OT2 - any help appreciated and photos to follow.

 

[ianmcd]

Are you sure that it is the Nest E that you have ? this is a battery powered unit and is hard wired to the boiler

 

[Alex Joyce]

 

[Alex Joyce]

Yes it is. The heat link has two rechargeable batteries and connects directly to the boiler hard wired and wirelessly to the Nest thermostat. Thanks.

 

[Alex Joyce]

Sorry for any confusion, the photos show the current Vokera Wireless Programmable thermostat wiring that I am looking to replace with the Nest Heat link.

 

[ericmark]

FP and then OT1 and OT2 are not used, just Com and NO to the 24 volt thermostat contacts.

 

[Alex Joyce]

Thank you so so much and that’s easier than I thought!

 

[Alex Joyce]

Hi Eric, sorry from the picture of the existing thermostat, which wires would be Com and No - it’s not easy to tell as two wires are black and the other are live and neutral? Many thanks Alex

 

[Alex Joyce]

Also the black wires are labelled on the Vokera wiring diagram as I and O if it helps?

 

[Alex Joyce]

 

[ianmcd]

the two black wires go to C and NO dont mess about with it as if you blow that PCB they are expensive

 

[Alex Joyce]

Thank you. Does it matter which black wire goes to which or just wire them to C and NO? Thank you for your help.

 

[ianmcd]

Thank you. Does it matter which black wire goes to which or just wire them to C and NO? Thank you for your help.

No it is just a switch, doesnt matter which way round

 

[Alex Joyce]

Thank you so much and That gives me peace of mind. Thanks again and have a great weekend!

 

[ericmark]

Com and N/O = I and O the wires to L and N need safely put to one side in case required in years to come.