Lowering boiler pressure.

[dave_cox]

Please help, i have a Europa combi boiler and i cant get the pressure to drop to the recommended 1.5bar, as a desult my overflow pipe outside my building is flowing, i have tried bleeding all the radiators but the pressure has only dropped to around 2.8bar from the 3bar it was sitting at. Is there anything i can do or do i have to call a pro in.

Dave.

 

[AnonymousImport]

If you look inside the boiler where the pipes are you will see a red handled valve open this by turning it and the water will run out of the system. Shut the valve when the pressure drops to 1 to 1.5 bar. How did the pressure get so high in the first place?

The valve may leak causing a drop in pressure over a period of time you can try to clear the dirt that will be on the seating by twisting the valve a couple times. It may work if not you'll need a new valve.

Post a reply if you have any more problems.

Good Luck

 

[dave_cox]

whats the name of the valve? the only red handled item there is, is from the diverter valve on the CH flow.

Should i be looking for the pressure relief valve?

Could the fact of the CH not being on for a while contribute to the buid up of pressure?

also there was one radiator on the system that would not completely bleed, it wouldn't stop flowing whereas the others seemed to bleed quickly.

Thanks for your reply.

 

[oilman]

Yes you are looking for the pressure relief valve (PRV). It usually has a red knob to turn. See if you can follow the disgharge pipe back towards the boiler and you may come across it. The pressure won't get above 3 bar as that's the PRV setting.

If you can find the filling loop disconnect it at the boiler end and see if it dribbles for ever. The stop valve may be leaking. Another possibility is the heat exchanger is leaking. Not an easy one to check.

If you can find the PRV let all the pressure off, then find the tyre valve on the pressure vessel and depress it momentarily to see if water comes out. If it doesn't, then check the air pressure. Should be 0.5 bar for a 2 storey building and 0.8 bar for a 3 storey.

Let us know what you find and we can try to diagnose further.

 

[dave_cox]

thanks for the replies, I discovered the problem was that the valve in the refill loop was switched on whereas it should be off at all times, i have lowered the pressure by bleeding the radiators again and the pressure is stable at 1.5bar.

Thanks again for your help.

Dave.

 

[oilman]

Not only should the fill valve be off, the filling loop should be removed. (It hardly ever is). The reason for taking it off is to protect your drinking water supply from contamination with class 4 boiler water. For more info see here