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Oct 17, 2017
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Poole
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Other Tradesman
Hi guys.

Wondered if anyone could shed some light on this.

I have an ongoing problem with my ultracom 30cxi that was fitted about 7 years ago. (Wish I’d bought a worcester).

I lose water pressure when the hot taps run. The boiler dumps the lot through the pressure relief valve.

The plumber didn’t fit any protection when the boiler was fitted, not sure if he asked me or not. So I fitted a Magna clean 2 a couple of months ago, it was the first time I’d heard about them. I’ve Serviced it a couple of times since, and the Magna clean is always full of sludge. I’ve ran some cleaner round the system by putting it into the Magna clean for the last few weeks.

I Changed the PRV which fixed it for about 3 weeks, now it’s back to what it was and occasionally the boiler cuts out with an F5 error, which I believe is an over heat code. I tried the heating last night as a test, and that didn’t dump the water.

Could it be the PRV, Again? Or the expansion vessel or the heat exchanger?

I’m an electrician, by the way, and had some advice from plumbers at work, but I’d love to hear your thoughts.

Many thanks in advance.
 
More likely a heat exchanger fault, but because you need to be GS to work on boilers that's all the information I am allowed to give
 
Thanks. If it is in fact the heat exchanger, I see there about £390 to buy.

Any ideas of approximate labour costs and time for a gas safe guy to replace one?
 
Have you checked the expansion vessel pressure? Could be a busted diaphragm in the vessel and nowhere for the expanded water to go when is run, but out of the PRV.
 
Expansion vessel change or re-charge, possible new heat exchanger Plate to plate. power flush, power flush power flush .. then Magnaclean .. and Liff or or Sesi to incoming cold
 
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Think your looking for the plate heat exchanger not the main one if its only dumping water when tap is run.
 

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