Hi, My old Baxi combi looks like its on it's last legs (11 years not too bad I suppose!) but I'm now having big problems finding a replacement that I'll be happy with. I've spoken to the energy savings trust who given me a ream of A rated combi-condensing boilers but they're listed alphabetically so I can't decipher which one to go for, for price, efficiency, longevity, etc. I've read there are some combis now that have a small reserve hot water tank to reduce the annoying waste of water and time lag whilst waiting for the hot water to 'appear' but again not convinced these are the best option as they'll need to keep heating it.
Any help would be appreciated - I'd like to know what boiler would offer the best solution for a victorian 4-storey house, so it'll need to be able to provide alot of BTUs - so i've been told! I'll probably get a wireless thermostat to help make the heating more efficient and all rads have TRVs.
The water is heated continuously. If it were timed, you could get up in the middle of the night say and have no hot water.
If this heat loss is a serious issue to you, and I don't think you need let it be, then go for a big standard combi. The instant heat output of the modern boiler is terrific, and will most likely suit your needs anyway and there really isn't too much delay in the flow.
It is more important from a flow point of view to site the boiler in the best position to avoid long pipe runs so the hot water reaches the taps quickly.