Gloworm Combi boiler pressure loss

[pdfctu]

Can anyone help me. Have a gloworm combi boiler. Pressure dropped to nearly zero. So topped back up using the filler loop. Fired up the heating but pressure keeps dropping, so i have to keep topping it up. It as if the water is escaping somehow. Have checked around all rads and boiler but cant see any leaks. Any help would be much appreciated

 

[Gasman1015]

Check the expansion pipe from the boiler (which is outside) is dry, otherwise pressure relief valve is leaking.

 

[gasgeezer]

which boiler is it model would be a help

 

[pdfctu]

Check the expansion pipe from the boiler (which is outside) is dry, otherwise pressure relief valve is leaking.

sorry do you mean if expansion pipe is dry, the p.relief valve is leaking. Or if the pipe is dripping, the valve is leaking?

Also if the valve (which i assume is inside the boiler) is leaking, would i not see water around the boiler?

 

[pdfctu]

Will have to check the pipe in the morning as I am not at home at the mo. Also will find out the boiler model when I get back and let you know. I didnt realise the model would make a difference to a problem like this. Sorry to be stupid - and thanks for you help so far

 

[Gasman1015]

If the pipe is leaking the valve needs replacing, it is piped to the outside in case of excessive expansion of the sealed system water.

Model does'nt matter so far.

 

[pdfctu]

thanks for that i will check and let you know. If the pressure relief valve needs replacing, is it something I could do. I have a basic understanding of plumbing, but have not gone near boilers before.

 

[Gasman1015]

Yes, easy enough.

 

[pdfctu]

Pipe is drpping a bit - so i guess need to change the prv. Can you tell me what it looks like?? and where abouts it will be - thanks

 

[Gasman1015]

That is where the make and model os the boiler comes in handy.

However generally they are located on right hand side and have a red plastic cap on a brass body about the size of a washing machine valve.

 

[gasgeezer]

what model is it. some are easier to change. also did the pressure loss coincide with heating being on is the pressure rising above 3 bar is it a built in filling loop or external one just changing the prv will not always cure the problem

 

[pdfctu]

Hello and thanks for help this far. The make is a Gloworm 24CI, it has a braided filler loop just below the boiler. Basically in the morning after the heating has been off for the night, the pressure is at zero. I have to turn loop on to get to bout 1.5 bar. Then I get hot water and can run the heating. While the heating is on it seems to be ok for water and heating. Its only when the heating goes off that the pressure drops after a while. With hot water only, again i turn loop to 1.5 bar, and can get hot water. After Hot water is off, pressure starts to drop after a while. Hope this makes sense, any further help would be much appreciated.

 

[Gasman1015]

Pressure relief valve on left side, take off cover, drop down control panel, red cap with lever.

Close isolation valves on boiler flow and return use safety valve to empty boiler, undo brass nut to pipe and remove clip at base of valve, pull out.

Manual here: http://www.glow-worm.co.uk/epower/gw/manuals/pdf/cxi_manual.pdf

Diagram 14: 13 Page 43.

 

[pdfctu]

thanks Gasman1015. Will give it a go this weekend. On that point do you know if i can buy a new PRV from a plumbers merchants or will i have to order one from Boiler company. I presume it is specific to the Gloworm 24CI?

 

[corgigazza]

This boiler also has problems from the flexible hose blocking up that goes to the expansion vessel, use a metal coat hanger to unblock(depressurise ex ves first) then recharge ex vessel