I haven't read all yet....
Boiler is too big. Get a correct sized boiler and fit zone valves and pump. Simple.
Daniel.
Boiler is too big. Get a correct sized boiler and fit zone valves and pump. Simple.
Daniel.
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A
AlexCarp
So all combis are too big then. Well do not write tripe then. Why do these people feel compelled to comment on something they know nothing about?
Yet that is not happening according to the informatiom You posting. And it cannot because the primary pipes and header are undersized for 3 pumps
A
AlexCarp
You still did not get it.
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15mm @ 18.1kw load would yield a velocity rate of 1.53 m/s (0.214/0.14)
22mm @ 40.2kw = 1.49 m/s
28mm @ 67.5kw = 1.47 m/s
Have you any idea the of the noise these velocity rates will impose within the pipework? also the air entrainment and long term effect this will have on the system???
You have obviously been googling your little heart out trying to gain this information , I say this because why the hell would you opt for a load rating of 40.2/67.5? Why not round the figures up??
You are baiting for information to which you will not receive.
As for header diameter being '3 Times the diameter' then it will depend upon application , maybe you can tell me the required header size for a 100 kw load @ 0.2 m/s velocity rate???
You are a googled and a bad one @ that.
As I said a complete and utter fool.
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John, don't feed the troll, he's a google warrior plain and simple with no idea of system design or header sizing and principles, unless it's wrote in google.
Know exactly where he's googles the 3x diameter as it's only quoted by one very specific manufacturer.
Know exactly where he's googles the 3x diameter as it's only quoted by one very specific manufacturer.
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Seems out posts crossed Lee.
Fookin idiot plain and simple.
Fookin idiot plain and simple.
Where did you get that from?
Now I read it all.
A good installer will fit a good sized vaillant system boiler with bypass built-in, 2 x zone valves for upstair and downstair radiators with TRV fitted, programable room thermostat, Unvented cylinder for hot water.
My 3 bed semi only need 12kw on a cold day and my boiler is happy 16 years old and still running sweet.
Daniel.
Yes, that's one of the big problems with combis - you either have crap DHW or a grossly oversized boiler for CH, or both.
That doesn't actually solve the problem. The heat demand is highly variable, and so the required flow rate round the CH circuit(s) varies. So there are mutually incompatible requirements for a minimum flow rate round the boiler, and a variable flow rate round the CH circuit(s).
That's what the debate is about. The ideal low loss header has negligible pressure drop across it - so the different circuits don't interact. But in practical terms, it's not the end of the world if the 3 circuits interact a bit - it's still a good deal better than the normal system with the pump working hard through the ABV most of the time, with plenty of noise as a result.
A
AlexCarp
Yes. That is why 22m pipe was used.
That is ballpark and many use that.
Can you tell us please? Try Google if you like. You have never given ANTHING of any use whatsoever. I would not let you near my house.
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AlexCarp
I did it and tested it. It works very well indeed. You make things up.
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AlexCarp
A knowledgeable and intelligent installer would do no such thing. Please understand heating or stick to drains.
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