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Plumberpro, Home Appliance Technician
Category: Appliance
Satisfied Customers: 634
Experience:  Heating and hot water heating appliances experienced
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I have an apha combi boiler. the hot water and central heating

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I have an apha combi boiler. the hot water and central heating are both working but the pressure guage goes up slowly towards the red even when the heating is not on and does not go down. I take water from the radiators to reduce pressure but it then starts going up again
Plumberpro :

Hi.within the boiler is an expansion vessel to take up the expanded hot water .within bhis is a balloon that over time goes flat ( sometimes it can tear) .when it goes flat the cycle that you have begins filling , over pressurising and so on . often when the pressure getsvto 3 bar it can dump out of the safety valve

Plumberpro :

The answer to this is to check the pressure in the vessel and with the boiler water drained ,pump it up to 1.5 bar. If the vessel doesn't pump up and stay pumped then the expansion vessel will need replacing

Plumberpro :

Hi , was your answer ok . if so would you please rate your answer , thanks

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