DIY Doctor UK DIY Forums

My central heating system has been losing pressure for approx 1 year (An old Vaillant 24Kw combi boiler).
I have been topping up periodically.
I have recently had a Vaillant Eco Plus 837 fitted and still losing pressure (Approx 1 bar in 3 days).
Only 1 radiator is losing heat (bathroom, no thermostat), i have bled this twice in 3 days then the system loses pressure. I have topped it up to 1.4 bar. There are no signs of water damage to any of the ceilings. :(

garyn31,
My top 3 suggestions are:
1. You have a leak somewhere in the system - add a leak sealer
2. The pressure vessel is faulty - replace the pressure vessel
3. System preserver has not been added and corrosion gases are being produced - add preserver to the system
I'm sure other forum members will have other suggestions.
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