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Plumberpro
Plumberpro, Home Appliance Technician
Category: Appliance
Satisfied Customers: 634
Experience:  Heating and hot water heating appliances experienced
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i have a potterton gold condensing boiler which have been installed

Resolved Question:

i have a potterton gold condensing boiler which have been installed only two years ago we have been having a problem just a few days ago, the hot water is coming very hot when we on the taps and after a second or so it goes cold . kindly advice me of what could be the problem. many thanks.
Submitted: 2 years ago.
Category: Appliance
Expert:  Plumberpro replied 2 years ago.
Plumberpro :

Hi . this is an issue with either a sludged domestic heat exchanger or hot water thermistor/temperature stat. Replace the stat first as its fairly cheap , if problem continues , clean or replace the domestic hot water heat exchanger

Customer:

Full Size Image

Customer:

please can you tell me which number on the diagram is the thermistor

Customer:

thank you

Customer:

is it the same as flue safety NTC?

Customer:

or is it NTC sensor or Overheat thermostat? because my manual is showing these three as three separate parts

Plumberpro :

Hi , its not on that diagram , give me a few mins thanks

Plumberpro :

Hi , its an NTC shown on page 43.

Customer:

is it the one on diagram 14.12?

Customer:

or 14.10?

Plumberpro :

Not sure we are onbvtge same page. If you go to page 43 it shows it there .it doesn't show it on the page you pasted in

Customer:

http://www.potterton.co.uk/docs/Potterton_Gold_Combi_HE_Installation_and_Service_Instructions.pdf

Customer:

this is my manual

Plumberpro :

Hi , I have the same one . it is shown clearly on page 43

Plumberpro :

Fig 89

Customer:

Thank you - will this solve the digital display to match the temperature of the water because only the display temperature rises the water doesnt get hot?

Customer:

Thank you i appreciate your clarification on this matter

Plumberpro :

, I think the fault is probably the Dom heat exchanger . when it gets a little blocked the water can't get through fast enough so the boiler ( on full heat ) gets up to temp quickly, then overheats almost straight away turns off , then cools , back on again etc . you end up with the hot water going hot then cold . if you feel the Dom heat exchanger while its doing this you will feel this happening. Have to let you know about the hot water temp sensor as well as. This an sometimes give similar fault

Plumberpro :

Yres it will solve the display

Customer:

is the Dom heat exchanger on page 45 FIG87 14.8?

Plumberpro :

Yes its the rectangle looking thing . has a waterway for the heating boiler water and a waterway for the cold water( comes in cold , heat is passed on through narrows fins , comes out hot , or should do

Plumberpro :

Some boiler guys clean them out but I find once they start to scale/ sludge they are never the same

Customer:

Thank you

Plumberpro :

Your welcome

Customer:

what is your recommendation to order the sensor?

Customer:

do i need to order it online or is it easily available in a plumbing shop?

Plumberpro :

The sensor is about 30 pounds easy to replace( turn off cold , unscrew and replace.) The heat exchanger is a bit more difficult but doable , especially when you have a bit of time

Customer:

I am happy to rate your service as excellent thank you for the advice

Plumberpro :

Readily available at good plumbing shop/ boiler spares

Customer:

thank you

Plumberpro :

No probs , would you mind rating your answer? Thanks

Customer:

i am doing it now :-)

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