Condensing combi boiler high flow

[ianmcd]

@DP no boiler interlock required in Scotland mate , only England and wales

 

[Hamedhbb]

why do you want your home to be 27 degrees?

To bypass thermostat and let the boiler control the CH. I set the temperature at the boiler and it’s 22. It’s for a test.

 

[DP]

@DP no boiler interlock required in Scotland mate , only England and wales

Ian if no boiler interlock required in Scotland, that does not mean one should not be fitted. In fact not to fit a boiler interlock is plain lazy as boiler will cycle unnecessarily when operational temperature is reached. While the boiler cycling will not be akin to a Flowmatic cycling, nevertheless modern boiler will cycle instead of switching off having reached ceiling flow temperature

To bypass thermostat and let the boiler control the CH. I set the temperature at the boiler and it’s 22. It’s for a test.

That is your prerogative. The function of the external sensor is to control the flow temperature at the boiler for seasonal or external temperature variation. Regret I cannot see the logic in not fitting a £15.00 component that will switch the boiler off when the room has reached a set temperature. To not instal a thermostat will mean boiler will continue to cycle, be it is minimum power, to maintain the temperature set on boiler control to achieve 22 that you aim for wasting fuel needlessly

Give me a programmable roomstat any day of the week over your precise precarious balance to achieve 22 degrees. I get frost protection, background heat and comfortable level from a single unit not to mention different variations at press of a button

 

[Hamedhbb]

Give me a programmable roomstat any day of the week over your precise precarious balance to achieve 22 degrees. I get frost protection, background heat and comfortable level from a single unit not to mention different variations at press of a button

do you mean a thermostat that uses opentherm or normal stat with timer function?

Thanks. I totally agree thermostat is needed because I have 2 zones and pump needs some rest. I am trying to see which way would be more efficient. I tried the above last night and distribution of heat was way more uniform. I set the knob to max until it reached 22 and then dropped the set point to 14 at knob. The 22 was maintained throughout the night. Burner was on 10sec every two mins at low flame. When I set boiler to max and use thermostat, because it overshoots/undershoots the pump will be of for longer periods which give air circulation enough time to settle. Colder air will be near floor and feet would be cold even if room is at the temperature. Last night we didn’t have that problem because radiator was lukewarm and it was getting warmer when outside temp was lower. So there was always a little bit of circulation to blend hot and cold air.

However in the morning that I needed to heat-up downstairs I had to set the knob to max until it reaches the temperature and then drop it to 14. This means the upstairs zone valve should be switched off using the room thermostat. Obviously this process is not practical to be done manually. I guess opentherm thermostats will do very similar thing automatically. Is that right? I am trying to see of the whole idea runs more efficient and if it worth the upgrade? It seems multi-zone opentherm is not that popular.