Boiler temperature what setting?

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I have a problem with rooms getting too hot, I have tried replacing the TRV heads for electronic ones, and adjusting the lock shield valves, much improved, but room for further improvement.

It seems the anti hysteresis software in the hall thermostat is likely causing the hysteresis in every other room? As room cools the valve opens, but if boiler not running it can open too much, then when boiler does run, the valve can't close fast enough, and with boiler switching on/off so often due to type of wall thermostat the TRV heads simply don't know what to do.

So what happens if I turn down boiler temperature, would I need to open the lock shield valves more or leave as they are? How do you know what to set it to?
 
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Sorry boiler is a Worcester Bosch Greenstar 25i and valves are Honeywell VT15 and the two rooms that over heat supply is lock shield side of radiator they are also closest to boiler. Also second by-pass valve fitted outside boiler as well as internal one. Electronic heads are Energenie MiHome.

OK room not much over temperature, typical 21°C when target set at 19°C, tried reducing to 17°C still hits 21°C. Today odd day out as tried to reduce flow in lock shield valve.
 
Turning down your boiler will reduce the heat output, where it might put out 80deg on full it might be 60 on low. Turn it down gradually until you feel it's right to suit your conditions.

I'd do it with the lock shield valves fully open as heat will dissipate more quickly through the rads. Having them restricted is just diverting warm water back to the boiler to be reheated.
 
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Lock shield valves do seem to have done the trick, no longer over shooting in morning, wife's bedroom target 20°C current 20°C can't improve on that, however would still like to know how the water temperature effects things like boiler cycling and loses out of flue? I assume lower the better as long as house is warm?
 
Lock shield valves do seem to have done the trick, no longer over shooting in morning, wife's bedroom target 20°C current 20°C can't improve on that, however would still like to know how the water temperature effects things like boiler cycling and loses out of flue? I assume lower the better as long as house is warm?

I tend to keep mine lower. Higher temp means you'll be burning gas at a faster rate but it won't have a greater noticeable effect. It'll still only get the house as warm as your thermostat calls for.

Think of it like flooring your motor.
 
I tend to keep mine lower. Higher temp means you'll be burning gas at a faster rate but it won't have a greater noticeable effect. It'll still only get the house as warm as your thermostat calls for.

Think of it like flooring your motor.
So as low as possible as long as house is warm is general rule?
 

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