Oil

[Dorr69]

You Hi
The bungalow I rent had an old boiler in until two years ago.
A new firebird boiler has been fitted. The hot water tank is separate.
I’ve bern looking at fitting a nest thermostat on it and been sussing out the wiring system.. I think!
Anyway, the pump is wired into a 3 pin round plug and socket on the wall and the boiler on a std 3 pin plug and socket beside it. These go back to a std Drayton controller
This boiler has no divert valve and as far as I can make out , when the pump is off ie hot water selected on the programmer, but when the ch is selected the pump comes on, permanently when the ch light is on
I guess that when it is just hot water and the pump is off the pump itself acts like a diverter valve ? And the water goes to the hot water tank by gravity ?
Is this a efficient way to run the boiler ?
So if the wall stat is turned down the pump is going regardless as long as the programmer has ch selected
I’m wanting to have a nest thermostat wired in but wasn’t sure if the boiler is set correctly

 

[ianmcd]

sounds like you have pumped CH and Gravity HW, it is possible to set the nest to control this but you need to buy the correct nest and most likely you will need an experienced engineer to wire and set it up properly, not just a straight swap

 

[Dorr69]

Thank you Ian
I suspected it was
The system set up is over 30 years old, and I expected the wiring to have been upgraded when the new boiler was fitted 2 years ago but it was just set up like for like.
There’s no zone valve and the pump seems to be used as a zone valve when the hw is set to come on, the pump is off. There’s no tank stat so how will the boiler know when to switch off ? Should it have a tank stat?
Also when the wall programmer is selected on for ch the pump is on regardless wether the boiler is called for heat via the thermostat. Is that the correct way ? I’d have thought the pump would only kick in when the boiler kicked in ? Seems silly having the pump running all day long while the boiler kicks in and out