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Bimboveloce
Joined: 27 Oct 2009
Posts: 8
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 Posted: Fri Nov 06, 2009 11:49 am Post subject: Pressure Loss On Combi Bolier |
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Hi I have a Potterton Performa Combi boiler approx 6 years old, regulalry serviced. Probem is I keep losing pressure when the central heating is run, no issues on hot water only.
The wife had the central heating on for a couple of hours yesterday and the bolier lost nearly half a bar. Normaly have it set at 1.5 when cold
I have checked all my bleed valves, connections, drain taps etc for leaks and cant see any problems.
Where can the problem be, is is the boiler, the pipework? please help got 2 young kids and i need the heating on.
Mnay thanks
Tony |
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htg engineer
Joined: 22 May 2007
Posts: 2628
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| Posted: Fri Nov 06, 2009 8:51 pm Post subject: |
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With the heating on, does the pressure rise to above 3 bar?
Check PRV discharge, any leaks ?
htg |
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rosebery
Joined: 26 Sep 2007
Posts: 1819
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| Posted: Fri Nov 06, 2009 11:48 pm Post subject: |
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Pressure/expansion vessel may need pumping up or the diaphram may be split.
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Bimboveloce
Joined: 27 Oct 2009
Posts: 8
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| Posted: Mon Nov 09, 2009 9:53 am Post subject: |
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I can say i have checked what the pressure is when the boiler is producing hot water and central heating, i will have a look. As for the PRV seems to have collected some water from it, about 1inch in the bottom of a coke can.
How can i check the pressure/expansion vessel or if the diaphragm is split?
Regards
Tony |
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Bimboveloce
Joined: 27 Oct 2009
Posts: 8
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| Posted: Mon Nov 09, 2009 10:53 am Post subject: |
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FURTHER UPDATE
Wife says heating has been on for 1hr, pressure is just over 2bar. When the bolier fires up the pressure goes up until is turns off and the reading is now 2.6, (in to the red zone) maybe why i am getting water from the PRV, but why is the pressure rising so much and into the red. Normal cold pressure is 1.5bar
Thanks
Tony |
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htg engineer
Joined: 22 May 2007
Posts: 2628
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| Posted: Mon Nov 09, 2009 7:21 pm Post subject: |
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Try re-pressuring the expansion vessel. Release pressure from system, using a foot pump, pressurise to 1 bar.
htg |
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Bimboveloce
Joined: 27 Oct 2009
Posts: 8
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| Posted: Tue Nov 10, 2009 11:36 am Post subject: |
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Thanks HTG for your reply.
Maybe silly question to ask but how do i re-pressurize the expansion vessel, where do i connect the foot pump and do i use the pressure gauge on the pump for reference? |
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htg engineer
Joined: 22 May 2007
Posts: 2628
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| Posted: Wed Nov 11, 2009 8:30 pm Post subject: |
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There'll be a schraeder valve on the expansion vessl (like a car tyre) connect foot pump, and pump to 1 bar (on the foot pump gauge) then refill system.
If there's any water when the schraeder valve is pressed, the expansion vessel needs replacing.
htg |
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Bimboveloce
Joined: 27 Oct 2009
Posts: 8
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| Posted: Mon Nov 16, 2009 1:21 pm Post subject: |
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Guy's I will try and pressure the expansion vessel and see if there is any water in it. I will let you know.
Whats the average cost to replace the expansion vessel if needed?
Regards
Tony |
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Bimboveloce
Joined: 27 Oct 2009
Posts: 8
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| Posted: Tue Nov 24, 2009 10:05 am Post subject: |
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Hi HTG,
I released the pressure from the boiler by twisiting the PRV until the gauge said zero, i then repressurised the expansion chamber with a foot pump as your suggested to 1bar and repressuresed the system. Boiler is working fine, pressure seems constant and with no loss. I will continue to monitor and hope the issue is resolved, if not I will be back on.
HTG engineer many thanks for your help, it has been invaluable.
Regards
Tony |
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