Massive overshoot of temperature HR92

[Adamhextall]

Hi guys...I'm losing patience now with my Honeywell system and want to ask if there is a genuine fault or if the system is behaving normally. The issue relates to one bedroom that currently has the HR92 on a single radiator as well as the location of the Honeywell control unit.

I have been at lengths with Honeywell support and so far have changed the TRV on the radiator and have tried 2 different HR92s and still the problem persists. Whenever the radiator calls for heat say at 18.5 when the temperature is 17 in the room the radiator heats up but doesn't shut down to at least 19.5/20c. It seems to shut down partially and then a delay of a minute or so and then a full cycle down after. By this time the radiator is at 20.5 !

Therefore there seems to be no control and wild swings in night temperature which can cause havoc when sleeping.

Any ideas or suggestions ? Thanks

[therealfronty]

It sounds like the radiator might be a bit oversized for the room, maybe something you can try is to reduce it's output by adjusting the lockshield valve, but I'm not sure the best way to adjust it. If you open it up you can reduce the temperature drop between input and output, so that might be one way, but the rad will still get hot, or you could try tightening the lockshield valve to reduce the flow, if you tighten it so that it is only just open then you'll be able to reduce the temperature of the radiator and make it "less efficient" - this might sound counter-productive but I think what you want to do is reduce it's heat output, so lowering the rads overall temperature by closing down the lockshield valve might be enough to prevent overshoots.

[mikey8156]

Hi guys...I'm losing patience now with my Honeywell system and want to ask if there is a genuine fault or if the system is behaving normally. The issue relates to one bedroom that currently has the HR92 on a single radiator as well as the location of the Honeywell control unit.

I have been at lengths with Honeywell support and so far have changed the TRV on the radiator and have tried 2 different HR92s and still the problem persists. Whenever the radiator calls for heat say at 18.5 when the temperature is 17 in the room the radiator heats up but doesn't shut down to at least 19.5/20c. It seems to shut down partially and then a delay of a minute or so and then a full cycle down after. By this time the radiator is at 20.5 !

Therefore there seems to be no control and wild swings in night temperature which can cause havoc when sleeping.

Any ideas or suggestions ? Thanks

I had that problem at first. Reducing the water entering the radiator fixed the problem. I then gradually every day increased the water flow.