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Aug 17, 2018
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1
Rochdale
Member Type
DIY or Homeowner
Hi everyone.
I have recently installed a new gloworm energy 35 kwh combi boiler. The heating and hot water is functioning fine. In the first 4-5 days , the pressure was dropping from 1 bar to 0.5 bar requiring me to top up the pressure. Its now been over a week and Ive noticed the pressure drop is less. It may drop from 1 bar to 0.9 bar in 2-3 days.

Is this normal? I contacted the vaillant helpline who told me top up of pressure should only be required 2 times a year.

Is this normal or abnormal?

Thanks
 
You have a leak. Ask the installer to return.
If its the existing system you should expect to pay for the repair.
 
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If the pre charge pressure is also 1.0 bar or more then the filling pressure of 1 bar will result in a relatively big pressure drop with virtually no water loss. Would suggest increasing the filling pressure to 1.3 bar with a cold system and monitor it (cold) for the next few days or so,
[automerge]1601290046[/automerge]
I think that the pre charge pressure for your boiler is 0.75 bar and if it has been checked before installation then you are losing ~ 0.5 litres each time the pressure falls from 1.0 bar to 0.9 bar so if this continues you definitely have a leak somewhere, also when system heats up just ensure that the pressure isn't > 2.5/2.8 bar.
 
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Check for obvious leaks (exposed pipework/magnetic filter/rad valves). Monitor it for a little while longer. Could just be air coming out of the system through the boiler air vent.
 

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