jacko
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| posted on 14/3/10 at 09:08 PM |
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Combi boiler help
Hi All please help
my son has a sime combi boiler and the heating is good BUT when you turn the hot water tap on the water comes hot then cold then warm and so on
Can any one tell us what is going wrong
Some one has said it could be the diverter valve but this person is not a heating engineer
Jacko
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ashg
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| posted on 14/3/10 at 09:39 PM |
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scale or air in the heat exchanger are the most common causes.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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austin man
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| posted on 14/3/10 at 09:44 PM |
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When my diverter valve packed in the radiators started to get hot when I ran the tap, also got warm water from the cold tap
Life is like a bowl of fruit, funny how all the weird looking ones are left alone
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deanwelch
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| posted on 14/3/10 at 09:52 PM |
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most likely to be scaled up domestic hot water plate heat exchanger...........best bet if you cant do it your self phone british gas and a fixed fee
of about £180 they will sort it
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jacko
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| posted on 14/3/10 at 10:13 PM |
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quote:
Originally posted by deanwelch
most likely to be scaled up domestic hot water plate heat exchanger...........best bet if you cant do it your self phone british gas and a fixed fee
of about £180 they will sort it
Can you tell us how to do the heat exchanger please
Do you mean clean it out
Graham
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ashg
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| posted on 14/3/10 at 10:21 PM |
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get the p/n off the one in it and buy a replacement. much better than mucking around with so called wonder cleaning potions that cost £15-20 a go.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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deanwelch
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| posted on 15/3/10 at 08:53 AM |
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plate heat exchanger will be held in by 2 screws or allen keys remove them (turn water off and isolate flow and return, drain boiler first) put
exchanger into solution of 50/50 boiling water and ds40(from plumbcentre around £25) for about a hour then flush out with cold water...........replace
the 4 seals or silicone GREASE them reasseble and test or british gas on 08005244854
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deanwelch
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| posted on 15/3/10 at 09:01 AM |
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new heat exchanger likely to be more than £180 retail or call british gas 08005244854
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thefreak
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| posted on 15/3/10 at 01:42 PM |
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Something as simple as the outside temp of the water? I've noticed in mine the max temp of the hot water will be x degrees, but that's x
degrees higher than the feed, so if you're feeding water in thats 1 degree, it's not going to be scorching coming out.
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DarrenW
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| posted on 15/3/10 at 02:33 PM |
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i had a similar fault with a Baxi a few years ago. It was the hot water diverter valve. Cant remember exactly how they work but i recall there was a
rubber diaphragm behind the valve that had perished. New diaphragm fixed it but it was a bugger to trace the fault.
The operation of the valve was something along the lines of in normal operation the boiler heats water for the heating system. When you turn the tap
on the heating water is stopped and the hot tap water is 'diverted' through the boiler. As it works on pressure a split in the diaphragm
stops the valve working correctly. You will get warm water and then cold soon after as there will be residual water in the boiler that is getting
warmed up over time, when you turn the tap on it is this amount of warm water you get out followed by cold.
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deanwelch
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| posted on 15/3/10 at 04:56 PM |
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i have done hundreds over the last 25 years any other heating engineer will tell you the same from the symptoms you gave.............if heating flow
pipe gets hot when you run hot tap then divetor is faulty.........if not plate is blocked.....if you can give more symptoms or boiler model even
better gc number **.***.** in this format and i will find out how much parts are but very likely to be bloody expensive........ps i dont work for
british gas i just like to tuck them up when i know how exoensive the parts are or other option take out breakdown insurance but you cant claim for 28
days............
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