glow-worm betacom 30 pressure problem/ please help.

[jd67stella]

i got a glow-worm 30 and it loses pressure all the time. ime in a three storey with ten rads and the boiler is on the bottom floor. ive kept the boiler running between 1.5 and 2 bar for ages without problems, but the pressure started to rise to 3.5 without reason. i changed the filling loop to a screw fitting instead of the usual black nob to pressurise it and it was fine for a time, but now the pressure shoots up again, i then have to take about 2 pints of water out of the closest rad to bring it down to 2bar again and its fine until the boilers off and the pressure drops down to a half a bar then the bloody red light is on and i have to refill the boiler again to 1.5 before it lights. but when the boiler warms up i got to empty the rad again and the process starts all over again. can sombody please help coz ime going bloody bonkers with this thing, the boiler was dripping water as well yesterday because of the pressure but i managed to tighten some bolts and it stopped. ime in the building game so i gotta bit of common sense, but boilers are a different ball game.

 

[m1key00]

Sounds as if your expansion vessel is gone, this is a part of the boiler that takes up the expansion of the water as it heats up. You could drain the boiler and check the pressure in the vessel using a car tyre pump with a guage on it (should be about 1 bar), there should be a small valve on the vessel to test this and no water should come out of the valve, but my money would be on it needing replacing, you could fit an external one if there are any places on the heating pipework suitable, but they are the size of a football and look a bit unsightly.

After this is done the pressure relief valve will need to be cleaned as they normally let by if disturbed.

remember though, if you have to take the combustion cover off the boiler to complete any of these jobs then is classed as gas work and should not be done by a diyer.

 

[jd67stella]

Hi thanks for the advise. I pressed the valve on the expansion for the second time and only air came out. The boiler is about 4year old and havnt been a problem but due to the recent cold weather it suddenly started 2play up. Ive just had to leave water out of one of the rads again as it went up to 2.5 again. If i leave it off the pressure drops. Red light comes on and i have to fill again.(nightmare) could it be anything else than the vessel.ok. now the boiler is nocking itself on and off. Ive nocked it off now but it was stating for 2seconds then off for 2. Then off and on again. Any ideas plz.

 

[Agile]

Follow instructions in the FAQ for repressurising the EXV.

Pressurise the air to 1.2 bar and then pressurise the water to about 1.8 bar.

Tony