No hot water!

[burtondave1972]

Hi there

am new to this forum and hope to receive some help on this topic, i am not a plumber or expert on heating, so any help would be appreciated

I moved house last week and have a conventional gas boiler (not combi) and have programmed the boiler to heat the water , and am only getting just lukewarm water thru kitchen and bathroom taps. I have increased to programme time from 30 mins to 4 hours a day and still no joy. When the boiler is on the radiators come on very hot, even tho the central heating side is switched OFF, so have had to manually turn off the radiators. The pump is working in the airing cupboard and you can hear the water heating up, and the pipes are piping hot in the airing cupboard too, going to the tank.
the only way i can heat the water is switch the emersion on in the airing cupboard but obviously gas is cheaper to use than electric.
Is there anyone than can point me in the right direction

thanks

 

[Mbear]

Gd chance it's a choked coil inside the cylinder from what ur saying.

I'd need to have a look myself to be positive though

 

[burtondave1972]

its a GLOW WORM boiler if thats any help, was serviced by British gas APRIL 2010 by previous owners and reported no problems,
have heard it could be a valve in the airing cupboard not diverting hot water to the taps?
sorry for my lack of technical terms!

 

[Mbear]

It's not important what boiler it is, it could very well be a 3port valve that is goosed causing the issue but u said the pipes entering the cylinder are getting hot which says to me the 3port is working, the problem seems to lie inside the coil, if it's choked it won't heat the hw.

 

[burtondave1972]

where is the coil situated , is this a diy job, or job for a plumber?

 

[Mbear]

where is the coil situated , is this a diy job, or job for a plumber?

Heat eng or plumber, no way a diy.

A powerflush may cure this but there's a good chance it won't, and then you'd be looking at changing the cylinder.

The coil is inside the cylinder. It snakes from the higher of the two pipes(flow) to the lower of the 2 pipes(return) round in circles and joins the 2pipes. All internal in the cylinder

 

[Puddle]

Is there a gate valve on the pipework coming out of the cylinder,if so,this is used for balancing and could have been closed down or blocked slightly,try opening up a bit if you have one ,also check for any air in the top pipework if there is any vents fitted on top pipework,also check header tank is full of water as maybe ball valve stuck and system starting to run dry


imho

 

[tamz]

If the heating was drained while the house was empty and refilled before you moved in it will be an airlock.
If pumped hw look for an airvent on the pipe that enters the cylinder about 18" up on the side. It will either be an air key vent (as on radiators) or a screw. Loosen it slightly to let the air out.
If it is a gravity HW system (the pipes will be 28mm) it is harder to do without experience (but still easy) and you will probably need someone to do it for you.
It is VERY rare for a std cylinder coil to choke as it is 28mm. Fittings or pipework yes, but never in 40 years came across a choked coil or heard of anyone who has.

 

[Mbear]

If the heating was drained while the house was empty and refilled before you moved in it will be an airlock.
If pumped hw look for an airvent on the pipe that enters the cylinder about 18" up on the side. It will either be an air key vent (as on radiators) or a screw. Loosen it slightly to let the air out.
If it is a gravity HW system (the pipes will be 28mm) it is harder to do without experience (but still easy) and you will probably need someone to do it for you.
It is VERY rare for a std cylinder coil to choke as it is 28mm. Fittings or pipework yes, but never in 40 years came across a choked coil or heard of anyone who has.

I've came accross it twice, both times the combined cold feed and open vent where tee'd off the flow to the cyl. The cold feed was choked and could be cut out however the coil was so badly choked the cyl needed changing. Because of the nature of a cylinder coil there is no chance of unblocking it if it's choked solid with hard magnatite.

 

[RoryD]

It may be the anti gravity / non return valve. Be worth getting someone in to check there isn't an airlock.

er.. I mis read the answers and thought the questioner had said it was gravity...if it isn't then feel free to bin my previous response

 

[pinghenglin505]

i would like to help, but sorry i also don't know much about it!

 

[burtondave1972]

Thanks for your advice guys,have had a plumber round and has diagnosed the three way valve in the airing cupboard as the culprit. No air lock blocked cylinder or buffered boiler which is a relief! The valve is a British gas one and ge has quoted £100 plus vat for the valve and £60 for fitting. There is a clone honeywell valve for £60 plus vat but he does not recommend that one as they not reliable.
Is that a fair quote?