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Plumberpro
Plumberpro, Plumber
Category: Plumbing
Satisfied Customers: 634
Experience:  Heating and plumbing answers. 20 years experience
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Pressure is rising on Worcester Greenstar HE Combi Boiler ZWB

Customer Question

Pressure is rising on Worcester Greenstar HE Combi Boiler ZWB 7-25. The pressure drops slightly when I turn on the hot tap. It's reduced it to 2.5 bar. The pressure starts to rise again once the taps are turned off.
Submitted: 1 year ago.
Category: Plumbing
Expert:  Plumberpro replied 1 year ago.
Hi , has the filling loop been left on slightly ? Or it may be letting by. Is the pressure going up even without hot water and heating on?
Customer: replied 1 year ago.
The filling loop is definitely off. Pressure kept rising. Stopped at 3.5 bar. Pressure was rising without hot water and heating being on. Pressure would drop to just above 3 bar when hot water was turned on and jump up again when tap was turned off.
Expert:  Plumberpro replied 1 year ago.
Hi, at 3 bar the safety valve should have opened and dumped water outside via a small copper pipe on the outside wall to the boiler.Did this happen?

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