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problem with hot water pressure

Posted: Thu Apr 23, 2009 6:06 pm
by martinj1207
Can anyone tell me the reason why the hot water pressure is so bad in my house is there anything I can do to fix it? The cold is fine but the hot water in the kitchen, basin, bath and shower (which has a water pump installed on it) are all terrible. Has been like this for a while now and have just had enough basically. Hane no tanks and everything is run off a combi-boiler which is quite old. Is it just simply that it is time for a new combi or could it be something else? Thanks

Re: problem with hot water pressure

Posted: Wed Apr 29, 2009 8:09 pm
by davis
martin is you systems direct or indirect ?

Posted: Wed Apr 29, 2009 8:15 pm
by davis
martin you system is a combi the best way to sovle this probelm is to make your system direct this will achieve better water pressure but this may not be the cheapest option but it will give you better water pressure in the long run. With direct no boiler need just an immersion inside cylinder

Posted: Sun May 03, 2009 3:08 pm
by blueplumber
[quote="davis"]martin you system is a combi the best way to sovle this probelm is to make your system direct this will achieve better water pressure but this may not be the cheapest option but it will give you better water pressure in the long run. With direct no boiler need just an immersion inside cylinder[/quote]

installing a "direct¿?" system will certainly [i]not[/i] make your water pressure any better. and as for taking out the boiler, then you'll be in for a few cold nights with no heating...

If its an old combi boiler, the it could be the DHW heat exchanger had been clogged up with deposits and need a good old descaling, os something a simple as the inline filters to the boiler need cleaning. Failing that, if the boiler is over 7 years old or so, then it could be on its last legs and time to replace.

Some of the new HE combi boilers can give quite adequate hot water flow rates.

or go for a new system boiler and invented mains pressure cylinder

Posted: Sun May 03, 2009 4:30 pm
by rosebery
davis - sorry to have to say it but thats abject nonsense -

First his system has neither a direct nor an indirect cylinder. He has a combi and has no tanks.

Second how is going from a mains pressure system to tank fed possiby going to give him better pressure? Mains at least 1 bar most likely iro 3 or 4, tank fed 0.25 - 0.5 bar. Your response is quite illogical unless you know something I and most others don't.

Cheers

Posted: Sun May 03, 2009 4:37 pm
by rosebery
"Can anyone tell me the reason why the hot water pressure is so bad in my house is there anything I can do to fix it? The cold is fine but the hot water in the kitchen, basin, bath and shower (which has a water pump installed on it) are all terrible."

I don't think you have a presusre problem. I think you have a flow rate problem. A combi works off mains pressure so the hot and cold will be at almost the same pressure whatever the input pressure.

"Has been like this for a while now and have just had enough basically. Hane no tanks and everything is run off a combi-boiler which is quite old. Is it just simply that it is time for a new combi or could it be something else? Thanks"

Many orginal combis were badly installed. The installers just connected them to the in place 15mm gas supply with the result that they were working at probably only 50% capacity thus only delivering around 6 litres per minute as opposed to the 12+ they were designed to. You say its been that way for a long time. So my guess is its a late 80s combi poorly installed. It may improve if you get the gas supply upgraded to 22mm but frankly I'd be thing about a new one if its 20 years old - modern ones are so much mire efficient anyway.

Get some Gassafe guys in to give you a quote.

Cheers

Posted: Sun May 03, 2009 9:26 pm
by uk_ducati
hi

i am a bit confused here. If you have a combi boiler you should have mains pressure from your hot taps.
if you have a combi, direct or indirect does not come in to it.
you say that the shower runs from a pump. if this runs from the hot feed from the combi you should not have a pump on it. pumps are mainly for tank fed systems.

Have you got a hot water tank or when you turn the hot water on does the boiler fire up?

paul