Honeywell T40 Thermostat

[ashyk36]

Hi all - I replaced my Honeywell T40 thermostat with my Nest thermostat when I moved. It. My boiler is upstairs and my Honeywell thermostat was in a closet downstairs.

I am thinking of removing the Honeywell thermostat as it is no longer needed. Question I have is, would the thermostat be wired directly into the boiler or would the thermostat be ‘wireless’ and draw its power from somewhere else?

Thanks

 

[EFLImpudence]

I replaced my Honeywell T40 thermostat with my Nest thermostat when I moved.

Ok.

It. My boiler is upstairs and my Honeywell thermostat was in a closet downstairs.

Daft place for a thermostat.

I am thinking of removing the Honeywell thermostat as it is no longer needed.

I thought you already had.

Question I have is, would the thermostat be wired directly into the boiler or would the thermostat be ‘wireless’ and draw its power from somewhere else?

The Honeywell is not wireless.

It might be wired direct to the boiler or to a valve.

 

[CBW]

If you said what type of boiler/system we can advise better.

 

[ericmark]

With a combi likely direct to boiler, with a system likely to the motorised valve, but as @EFLImpudence says, why is it still there and in a cupboard, is it some frost protection or similar?

Note no connection to terminal 2, this means the switch on and off temperature have a huge difference, this can with some systems help, in the main room temperature is controlled by the TRV,s, however they have a problem, unless the water is circulating, they can't tell the boiler what to do, so we need a wall thermostat to turn off the boiler in the summer. And a large differential helps with that.

I also have Nest Gen 3 and a thermostat like you show, the Nest tries, although not really very well, to control the main house, bit of a useless thermostat, but wanted one which could use the two existing wires to main house, and the other thermostat controls the flat under the house, they control the motorised valve which in turn controls a relay which in turn controls a pump and boiler, but heat link (Nest) also controls boiler direct for domestic hot water.

OK my house is maybe unusual as I can turn off the flat when not in use, but using a C Plan and yet have two pumps and two motorised valves, plus relays as only one set of contacts in the valves, and two pumps. But the point is we have no idea what is in your home, likely not as complex as mine, but how do we know?