Sounds like a gravity hot water system then. I think we better wait for someone more knowledgeable than me to check this is right, though. If it was pumped, there would also, I think, have to be some sort of motorised valve to divert the water from the heating to the cylinder. I remember in the early 1990s, when we got our new house with fully pumped, it was so much easier.
Any reason to move a new boiler?
- Thread starter gerbils
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No, it wouldn't do! Is the water pumped through the HW cylinder coil? Do you have a motorised 3-port valve? (or two 2-port valves)
Oh, and ignore those pushing combis without a good reason. They're in it for the money.
OK, but if so they should have said so.
Not necessarily. Combi makers will quote a figure based on all the daily use in one hit. In a more typical situation of many small draw-offs maybe use more gas
That's very cheeky of them.
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Thanks. They did mention hot & cold pipes, but they are quoting without seeing it.
If you end up with a combi in the loft suggest they put a filling loop and pressure gauge in the airing cupboard so you can keep an eye on it and can top the pressure up without having to climb into the loft.
I don't understand how they can do that. We do need much more information about your present set up, and some photos of the boiler and flue outside.
Combi's are a one box solution, where most of what can go wrong will be in that box, which will need a Gas Engineer to fix it. All hot water demand usually needs the boiler to fire up and you to wait whilst it becomes warm, wasting gas needlessly in the meantime. The boiler also has to be over sized to meet heating the water, rather than sized to heat your home, another potential for wastage of gas.
Filling a bath from a combi, is much slower than when compared to an open vented system which you would seem to have.
An open vented system is much more expensive to initially install, than a combi, which is why so many favour them.
As suggested above, if what you have is an heat only boiler, you will almost certainly need a larger capacity gas supply pipe installed from the meter, to the boiler. Often that pipe will have to be routed via an outside route, which can look awful.
I have my heat only boiler in the loft. Hot water cylinder in the airing cupboard in the hall downstairs, pretty central to kitchen sink, ground floor WC and first floor bathroom. Hot water gets to all three in about ten seconds.
My mate has a combi boiler in his loft and it’s a good minutes wait until hot water reaches his kitchen sink. Of course he's wasting water waiting for hot to arrive and when he turns the tap off, there's a couple of sink fulls of hot water in the pipe that is wasted when it cools down. They either usually wash up in cold water or use the kettle. Pain in the arse with a combi in the loft when you need just a sink full of hot water in reasonable time downstairs.
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A mate of mine has the same. I urged him against it but he wouldn't listen and now regrets it. He's thinking of going for a heat pump, has no mains gas.
Well said Jeff.
What boiler do you have?
If you already had a full tank of hot water the pump wouldn’t respond to the demand from the programmer.
That might be the case if starting from scratch, but probably not if upgrading an existing non-combi system.
I wasn't saying otherwise.
I know, but I mentioned it in case anybody got the wrong idea!
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