Potterton Puma 100e Comb Bolier-NO HOT WATER but CH OK

Can somebody suggest what could be wrong with my combi boiler? The hot water is luke warm/cold but boiler is fired up and heating works ok. It appears to me as if the diverter valve is routing the cold water the wrong way and hence it is not passing through the boiler to be heated? Does this makes sense? Should I change the Diverter valve or can you get service kits to repair it? In the weeks leading up to the problem the hot water was fluctuating between very hot and then cold when using the shower. Interestingly enough if i turn the hot tap on only slight to reduce the flow right down then the water comes out very hot - does this make the picture any clearer as to what could be wrong?

I have spoken to Potterton who told me they do not fix boilers older than 10yrs and then hung up the phone on me!!!! It seems a waste to replace a boiler when this is the first problem I have had and there doesn't appear to be too much wrong with it - any help or advice would be appreciated - Thanks

I don't know if there is a service kit for this, but I always replace dv's rather than recondition, that way I have a warranty to give the customer.

Turn CH off and from cold system turn on hot tap. Does either CH pipes or rad get warm at all? If so problem is diverter valve. If not, could be knackered water valve diaphragm. Suggest you test water flow through hot tap. Should be around 10 litres a minute to heat up to 35 degrees. Any more than that and the HE wont get enough heat into the water which will be lukewarm.

Hope this helps.

Scrufflepeck

Does your boiler fire up for HW demand when cold? Could be many things, the diverter not being one of them!

Scrufflepeck said:

Turn CH off and from cold system turn on hot tap. Does either CH pipes or rad get warm at all? If so problem is diverter valve. If not, could be knackered water valve diaphragm. Suggest you test water flow through hot tap. Should be around 10 litres a minute to heat up to 35 degrees. Any more than that and the HE wont get enough heat into the water which will be lukewarm.

Hope this helps.

Scrufflepeck

Click to expand...

Have done as you suggested and both CH pipes get warm near the diverter valve. The DHW pipes on the diverter valve at the fron of the bolier get colder. So would this confirm the diverter valve - why does the water get hotter if I only open the hot tap very slight i.e. restricted flow from hot water tap and water gets hot?

All fixed the problem was low gas pressure <4mBar due to a faulty regulator on the gas meter.

Problem is the BG Engineers diagnosed a faulty diverter and replaced this before checking the GAS pressure. The regulator was replaced by Transco for free so I need not have paid to get bolier fixed as there was no fault with the bolier in the first place. I have disputed the charge for bolier repair due to incompetence by the Corgi registered BG engineers who I believe should have checked the Gas pressure first before they even looked at the bolier. Is this correct assumption?

Any comments welcome on whether I have a good claim against not paying for the boiler repair would be appreciated?!

rob884 said:

Could be many things, the diverter not being one of them!

Click to expand...

As i was sayin...

4mb burner pressure compared to the correct 13mb could have been visually diagnosed!

Any fitter on site attending any fault to do with lack of hot water or power from a boiler should always check the working pressure first, then inlet pressure on the appliance, then burner pressure before further fault finding goes ahead.

On these forums we tend to assume basics like this are all ok a lot of the time, wrongly so in this case, but then we haven't charged you.

Get your money back or threaten to call corgi in

stufix said:

All fixed the problem was low gas pressure <4mBar due to a faulty regulator on the gas meter.

Problem is the BG Engineers diagnosed a faulty diverter and replaced this before checking the GAS pressure. The regulator was replaced by Transco for free so I need not have paid to get bolier fixed as there was no fault with the bolier in the first place. I have disputed the charge for bolier repair due to incompetence by the Corgi registered BG engineers who I believe should have checked the Gas pressure first before they even looked at the bolier. Is this correct assumption?

Any comments welcome on whether I have a good claim against not paying for the boiler repair would be appreciated?!

Click to expand...

It was YOU who called BG and I assume that they were doing a fixed price repair for you. Eventually they found the fault so they have fullfilled the Contract. The fault was not in the boiler but it still needed to be diagnosed and corrected.

Its still a chargeable visit even if the boiler is not turned on at the wall or some other simple user error. We are a not a charity! You call us and we come out and trace the fault.

Their incompetence has gained you a new diverter valve!!! You should be pleased.

Any experienced boiler engineer would have tested the boiler on arival and noticed the small flame size and immediately have measured the working and burner pressures.

Depending on the type of fault it may be more appropriate the check the gas pressures on arrival or later on depending on what is found on the initial assessment testing.

Tony