I currently have a back boiler which for various reasons I want to swap to a combi - the combi being located in a different position. Im trying to identify the pipes into the back boiler, ther are 3 22mm pipes, could somesone confirm what these are, the system works with a 2 port valve - not the 3 port i have seen on all other schematics and CH explanations
Your help would be greatly appreciated
Are all 3 pipes connected to the heat exchanger, and carrying water - or could one be the gas supply?
Have you only got *one* 2-port valve - or are there two? Does your system layout match any of the 'plans' in
If so, which? Otherwise, can you take some pictures of the boiler - with a gas fire removed - and of any equipment (pump, valves, etc.) in the airing cupboard - and upload them somewhere and post a link here?
Are you *sure* that you want a combi? It's perfectly feasible to have a modern condensing boiler elsewhere but *still* have stored hot water in addition to central heating.
Quite likely they are heating flow, hot water flow, and a combined return through an injector tee.
I believe the effect of the injector tee is that the returning pumped water through the radiators "sucks" the gravity fed indirect hot water circuit through the cylinder. This ensures that some of the output goes to the hot water when the radiators are on.
Most boiler manufacturers will provide old manuals for free if you call them. It might be worth getting one.
Mr F.
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