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Tim Cooke
Tim Cooke,
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My combi worchester boiler is working fine when the heating

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Hi my combi worchester boiler is working fine when the heating is on but when I turn the hot water on the reset button pops up any ideas
Assistant: How long has this been going on? And how severe is the problem?
Customer: Expansion vessel was gone had a external one fitter yesterday and is started from that thanks
Assistant: Do you plan on doing the work yourself?
Customer: No just would like to have an idea why it's doing it
Assistant: Anything else we should know to help you best?
Customer: The pump is roasting hot to touch
Customer: replied 7 months ago.
Just noticed when the heating is on its fine and when the hot water is on it's fine the problem starts when both are on at the same time the reset button will pop up

Hello, please can you tell the model of your Worcester boiler?
Also, when was it installed (if you know)?

Customer: replied 7 months ago.
Worcester 28i think it's an old one it's not digital must be about 10 years old or over
Could you confirm that the radiators are getting hot? Do you have a motorised valve near the pump?
Customer: replied 7 months ago.
radiators get hot , water gets hot , it's when they are both on at the same time as soon as you turn the hot water off the red button pops up and you get a banging sound , not sure about the valve ?
Could you take a photo showing the pump and all of the pipework around it?
Customer: replied 7 months ago.
That picture any help
Customer: replied 7 months ago.
I can’t really see any pipework in those photos.To recap, the boiler overheat thermostat trips when you open a hot tap? Have I got that right?
Customer: replied 7 months ago.
I trips when the hot tap is turned off , only when the heating is on ? If radiators are off it does not trip ?
That behaviour suggests a fault in either the thermocouple or the PCB. Has anyone done any work inside the boiler casing recently?
Customer: replied 7 months ago.
Got a new fan last year that's about it , when the expansion vessel was ruptured it all went down hill from there , sorry for my ignorance but Whats the PCB
Customer: replied 7 months ago.
The circuit board !
circuit board.When you say that the expansion vessel ruptured, did it just fail internally or was it leaking externally?
Customer: replied 7 months ago.
it was leaking externally ,
In that case someone must have blanked off the expansion vessel connection, which means they were working inside the boiler casing. Why did that person not fully test the boiler functions after completing their work? Are they Gas Safe registered?
Customer: replied 7 months ago.
they were it was a boiler company that came out . He pressed the valve on the vessel and water cane out told me it was ruptured and fitting a external vessel would be easier than taking the boiler off the wall .

It's certainly true that adding a second expansion vessel outside the boiler casing is a cheaper option, both in the short and the long term.

The word "ruptured" is a bit strong if it was simply the diaphragm that failed. That implies no external leak, in which case he wouldn't need to do any work inside the boiler casing, except to discover that failure.

If the vessel had been leaking water externally, he would have needed to uncouple cap off the connection to the vessel, in addition to installing the second expansion vessel..

Either way, the engineer should have tested the system, and ensured that there were no faults, before leaving. If he didn't, then I suggest you ask him to come back and do his job properly.

Tim Cooke and other HVAC Specialists are ready to help you
Customer: replied 7 months ago.
Thanks very much for that I will get hold of them