No hot water, without heating on!

[handyandy0_8]

I have a Baxi combi boiler about 4-5 years old. The hot water has never really run that hot, but now it seems to only get tepid unless the heating is on. Not so much of a problem in the winter, but during the 'summer'!!!
Can anyony suggest if there is some 'internal' adjustment which may need tweeking, or if anything could have failed and caused this.

 

[ollski]

yes the diaphragm in the diverter valve...post us the model and we may be able to help more.

 

[handyandy0_8]

Ollski, thanks for your reply, the model is Baxi Combi 80Eco. I have noticed that the central heating loses pressure also without any apparent leaks. Could this have anything to do with it?

 

[gazthepottertonengineer]

sounds as if problem is hot water plate heat exchanger probably got sludged up you can just take it out and clean it out but replacing it would be best

turn off all valves underneath drain boiler and then its just 2 screws simple

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also how long is it taking for pressure to drop icon_confused.gif check prv (pipe sticking out wall outside) to see if that is dripping water if not probably small leak on system icon_confused.gif

 

[DP]

Was this a replacement boiler? Was the system chemically cleansed and gas line uprated for a combi boiler?

Dirt (from existing radiators if system not cleaned) will effect hot water delivery. Inadequate gas line, adequate for previous boiler of nominal output, will mean undersized burners so already poor (combi) hot water delivery will me much worst.

Problem could be domestic manifold sluggish, ruptured diaphragm or diverter valve cuffed. Service (not the 15 minute operation check) should put the boiler back on track.

 

[handyandy0_8]

Thanks gaz' The pressure drops over about a 1-2 week period. Will check the pipe to see if it's dripping. Do you know any schematics available on the web which would help with identifying the hot water plate and the retaining screws?

 

[kevplumb]

here

 

[handyandy0_8]

DP' Thanks. This was a totally new system including radiators, the house origionally had electric storage heaters. We had to have a gas supply to the house which British Gas did.

 

[DP]

You can take nothing for granted until you have seen it with your own eyes. A correctly installed system would have been cleaned with chemicals (yes, even new install), treated with corrosion inhibitor and benchmark logbook completed and handed over to the client along with boiler documentation.

Not for the first time have I visited a client with a nearly new boiler with a blank logbook and no boiler manuals. Unless the engineer/ installer is carrying out the install by numbers, a fair number of corners are cut sometimes to rush through the install.