Biomass boiler

[openspaceman]

Cat, yes I lose water from the house header-tank over flow.

 

You could just put another in parallel and join the bottoms, there is an issue with plastic headers since a child was killed when one burst over its bedroom.

 

I'd seriously consider going unvented if you can source a cheap accumulator and pressure vessels, lots of upsides and few down, if any.

 

 

At the moment the boiler is off through the summer and DHW is heated by immersion heater, my hope is that while heading the pool I can turn off all radiators and still heat the DHW, via the indirect coil in the immersion cylinder.

 

Consider a simple zone system, like the standard S plan: a programmer and 2 honeywell zone valves. Have the DHW on one zone, space heating on other and run the DHW and pool in parallel, the DHW temperature set by a tank stat controlling its zone. When it is satisfied all the flow will go to pool.

 

In winter you will need to arrange some sort of pump over compensation should the DHW and heating circuits become satisfied. As the programmer will not be controlling a burner you will be able to use the redundant contacts on the zone valves in series to cut the primary pump. I think you are bound to need a separate pump for the boiler to the accumulator.

[openspaceman]

As the programmer will not be controlling a burner you will be able to use the redundant contacts on the zone valves in series to cut the primary pump.

 

Sorry the above is wrong, I meant parallel, meaning the pump won't run unless one of the zone valves is open.