CH on heats HW, and HW on heats CH (Ed.)

[Shimlasun]

Thanks. So if we don’t get an immersion heater, the CH will always come on with the HW whatever we do? That’s one of the main issues as the thermostat then doesn’t switch off the CH when it reaches the correct temp and the house gets too hot..

 

[ericmark]

Thanks. So if we don’t get an immersion heater, the CH will always come on with the HW whatever we do? That’s one of the main issues as the thermostat then doesn’t switch off the CH when it reaches the correct temp and the house gets too hot..

Sorry that is clearly wrong, you should be able to turn the CH off when using boiler to heat DHW, it is the other way around when there is no option, you should not be able to turn off DHW when the CH is running.

Since the DHW heats up far faster than the CH will heat the house, if there was a thermostat on the DHW then it would switch off well before the house is warm. However at least my house has no thermostat connected to the boiler to tell it when the DHW is hot, so DHW was on a timed run only, in summer ½ hour 4 days a week.

In winter we have the DHW always set to off. we have the CH set to different temperatures through the day. Two thermostats on in hall and one in living room can turn on the boiler. However even it the thermostats did go haywire and fail to turn off boiler, the TRV heads would stop the rooms over heating I have three different types of TRV heads, showing the Kasa, but what ever happens to the boiler controls you can't over heat a room, as the TRV head will turn off radiator, you would need multi faults to overheat a room.

 

[Shimlasun]

Thank you. So for someone who doesn’t understand all the details, and we don’t want to change anything else just the controller for now, are we better off going with Drayton LP822 or Hive might be best… and per RandonGrinch..
or are you saying even with these controllers, they won’t heat HW without also switching on CH, so we’ll be in the same position? It must be possible to heat HW alone with our current setup because it used to work ok, the only issue was it was on the boiler in the garage and needed bringing inside hence changing the controller.