I have a feeling it's a neutralizer. If so, what exactly does it do and what's it benefits?
Looks like a gloryfied Low Loss Header to me![]()

That's what I thought! The house was beautiful, really plush fixtures and fittings, why not spend a little on the boilers.....
Since posting this i've been to www.dunsleyheat.co.uk which explains alot. Looks like a neutraliser isn't really necessary in this case, i think they're designed to connect different kinds of heat sources i.e. gas/oil and solid fuel, rather than two sealed system boilers. Might as well have just piped two regular boilers in parallel, there are 5 pumps involved here!!
The boiler head loss can be dis-regarded when calculating index circuits so simplifying the process

I may need setting straight here but reverse circulation on a standard Y-plan system would occur when there are radiator returns piped up after the hot water coil return? I.E. those rads could potentially heat up when on hot water only?
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