Glow worm combi losing pressure

[kazgaz]

Hello everyone!

I've got a 10yr old glow worm combi serving seven 10 yr old rads and 1 towel rad.

All's working ok but the pressure guage on the boiler had recently dropped to zero. One of the rads downstairs was leaking at the top where the blanking plug is, there's a bit of corrosion around it, but once I tightened it up, it stopped leaking. I fill it back up to 1 bar and when the heating's on the presure goes up to over 3 bar and all the rads are very hot and there dosen't seem to be any air locks or leaks of any water anywhere. But once it goes off and cools down, over the course of a couple of days, it drops down to zero again. Even if I leave it at 0 bar, the heating still works, goes up to over 3 bar and all rads are hot as normal. The plug that was leaking on the rad downstairs is still watertight.

When we call for hot water, again, all's ok.

Any ideas greatly appreciated

Cheers!!

 

[kitch0978]

its probably the expansion vessel inside the boiler that has failed....when your heating is on does the pipe that goes outside leak? should be able to see a copper pipe that goes from boiler to outside....when it gets outside it should be bent into the outside wall........

 

[kazgaz]

Hi kitch0978

Just been outside to check and there is definately small amounts of water in the pipe, no massive amounts of drips on the floor, but when I stuck my finger in, it came out wet!

Is this going to be expensive!?

Thanks again

 

[kazgaz]

Anyone ?

Thanks

 

[gas4you]

Search FAQ's for how to check/replace your EV. It may just need re-pressurising.

 

[kazgaz]

Hi everyone

Had a British Gas engineer out to fix the problem.

The expansion vessell did need re-charging and he also replaced the blow-off valve, saying that the seals can get s***e in them and not re-seal properly. Whilst he was here he gave it a service as well.

So alls good here and thankyou to the people who replied to my post, very much appreciated!

kazgaz