Why Does Boiler Pressure Reduce Frequently?

[Sunny888]

When I let the air out of the radiators I put the pressure back up to 1.5bar as instructed on the Potterton Condensation Boiler.

After a week there seems to be air in the system and the radiator has to be bleed again. When I go and check the boiler the pressure has dropped to little over ZERO bar.

It seems the boiler is loosing pressure all the time, I have repeated this around 5 times now.

I have asked "Plumbers" before but unfortunately they have not been helpful.

Can anyone help?

[The Builder]

could be a number of things Sunny...............any one of which would need investigating................get a proper heating engineer to look at it...............try asking Potterton for local names :o)

[gucciman]

if your sure the air is being replaced by air then i would suspect leak somewhere on the system.

[buildersmate]

If you are getting gas in the system, it is most likely to be caused because you don't have any or enough corrosion inhibitor in your system. The water is reacting with the steel of the rads and producing magnetite (black sludge and hydrogen gas. This gas collects in the top of the rads, increasing the pressure. If it rises above that of the relief valve, typically set at 3 bar, water escapes from the valve.
You then discover what you think is 'air' in the system, remove it, reducing the pressure which falls below 1.5 bar because some of the origianl water escaped. So you refill it. More chemical reaction occurs and the process repeats.

[gucciman]

sorry i meant if the water is being replaced by air