Firstly I've found the boiler classification from my old datasheet:-
1 *Solid fuel boiler not controlled by a water sensing thermostat
2 *Ditto controlled
3 *Conventional gas/oil fired boilers with low resistance heat
exchangers
4 *Low water content, high resistance gas boilers.

Right! Does this refer to the existing CH boiler or the one you are
trying to link up? My existing is a Potterton Profile which I guess
comes into the conventional gas/oil fired boiler with low resistance
heat exchanger category 3.

Oil CH boiler (type 3) goes in one set of ports, uncontrolled wood
burner (type 1) goes in second set of ports.

er... do you not have motorised valves routing water into the coil or CH
or both? I suppose this is their fancy electrically fail open valve.


One motorised valve in feed to tank only - driven closed when CH is
called for and the CH pump is running. If I remember rightly the
logic makes sure that all heat using sources are available if the wood
burner gets hot. I seem also to remember that 'electrically fail open
valve' is the norm.

I would support DD's comment that you might well also consider the
heatbank arrangement. The Neutraliser is a mini heatbank in reality,
and the cost and complexity of fitting might well be put to giving you
mains pressure ho****er too.

Rob