seeking advice: use of system boiler for unvented HW and CH

[Leon Hurst]

Hi, I just moved into a house with an old unvented HW system which is powered by a system boiler (gas)
that is also used to heat the CH system.

Q: what "power" setting should I put the system boiler to (it is a Prima F with a range of 1-6)?

I ask this as I expect the unvented HW system needs a good hot feed for its exchanger. We like
piping hot water and have replaced all taps with good mixers with child safety buttons.
On the other hand I expect (please correct if wrong) that the CH system would need a
lower boiler setting so as not to over heat the house and waste money (note all radiators have thermostat valves).

Many thanks.

 

[SimonG]

Does your cylinder have a cylinder stat,if so it is this (if working) that controls your hot water temperature. Set your boiler stat for the rad temp and the cylinder will take care of itself.

 

[Leon Hurst]

thanks, just found it under a plastic panel on the cylinder.

 

[J c stokes]

If theres a cylinder stat, programmer and room stat all turning the boiler down will do is cause it to do is fire up then get to temp and then kick off a lot. IMO its better to turn boiler to max and control heating via room stat, programmer and thermostatic rad valves in individual rooms. If it's a condensing Boiler then turning it down slightly will allow the boiler to condense more effeicently therefore saving some money