Nest thrmostat install to worcest heatslave 20/50

[Hytech Steve]

Hi All,

Has anyone fitted NEST to this boiler as it has on board 3 position valve. Surely you do not have to cut into boilers on board wiring loom as its all plugs & skts. The Nest diagrams only show seperate DHW & CH motor valves. ????

 

[leesparkykent]

you could use Terminal X4 or terminal X2 depending what nest you have.

 

[Hytech Steve]

Hi Leesparkykent,

Thanks for reply. This customer wants to control CH & DHW from the Nest so I guess the motor valve needs to move position. Not a problem getting the boiler to come on but if I think correctly you have to get the programmer to be on all the time or am I missing something?? As this boiler is basically a Combi unit does this mean I should'nt touch as I dont have the cert for pressure system??

 

[NozSpark]

As Lee said,,,, just wire the Nest to the X4 plug,,,, you'll have to refit the thermostat link though!

You're only fitting the controls, not messing with the pipework, so as long as you're competent crack on

 

[steptoe]

Depends what nest you have

I've had an ongoing issue with a LL that has bought a load of CH only nests and he wants to know why he can't control DHW with them, :slap

 

[Badger]

but surely a combi on the dhw heats the water as the required need arises from the tap being turned on.

 

[steptoe]

but surely a combi on the dhw heats the water as the required need arises from the tap being turned on.

Yes, but why can't he control the temp as tenants saying hot water too hot, or too cold, I'm not sure they have for the idea of how mixer taps work, :slap

 

[Rob_the_rich]

Hi Leesparkykent,

Thanks for reply. This customer wants to control CH & DHW from the Nest so I guess the motor valve needs to move position. Not a problem getting the boiler to come on but if I think correctly you have to get the programmer to be on all the time or am I missing something?? As this boiler is basically a Combi unit does this mean I should'nt touch as I dont have the cert for pressure system??

it is not a combi. If the thermal store is not hot, no hot water will come out of the taps. look at the manual https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwj6zof4q-vNAhXlL8AKHTS2CgQQFggfMAA&url=https%3A%2F%2Fwww.worcester-bosch.co.uk%2Fsupport%2Fdocument%2Fdownload%2F8716104440&usg=AFQjCNE96FJ1UxrhSWEz4sL6vUsln0h5_A&bvm=bv.126130881,d.ZGg and follow the instructions for fitting an external programmer (ie the nest), as Lee mentioned above.