Nest E thermostat temperature control

21 May 2022
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United Kingdom
I would like to swap my old Honeywell thermostat for a nest e thermostat. I have two wires connected to combi boiler Ariston e combi evo.
Do you think, if I connect one wire to c and the other to no on the nest, it will work?
Also I'm not sure how it controls temperature. Is it one of the tpi thermostats that will turn the boiler on and off all the time, like Honeywell dt90e?
Or can it be used as a traditional thermostat with 0.5 degree swing? Providing that the relevant smart function is turned off if possible?

Thank you for any help.


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if I connect one wire to c and the other to no on the nest, it will work?

Although it would be advisable to put some brown sleeving over the blue wire to denote that it's also live/switched live.

There might also be a need to tidy the wiring coming out of the cable trunking - there appears to be a strand of copper cable poking through, where the trunking ends and the sheath of the cable should ideally enter the back box of the thermostat.

....although blimey!
Given the content of your previous posts, how many thermostats do you get through in a year! :)
Yes, Nest e is a 2 wire thermostat, which is how yours is wired and get some brown sleeping on the live in (blue) to confirm to anyone else it’s a live, if it’s a mains switching wire. Not sure if it works in 0.5 degree increments.
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Thank you for your replies. I'm sorry about all the posts, I'm struggling to find the perfect one. I have considered a lot but only bought Honeywell dt90e, which is a tpi one and it was a nightmare. Turning on and off all the time, not enough time to even cycle the water through the system.

I really want the nest e but if it is the same tpi type thermostat, or the feature cannot be turned off then it's a no go.

Does anybody know if it can work like a normal thermostat please?

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