Main combi eco 30 boiler

[toeknee8]

God I am getting soooo cheesed off now with my boiler. Does anyone know if my diverter valve is the problem for the following: I am loosing pressure every day and have to top my boiler up, running at 2bar pressure.
The DHW keeps going hot and cold, however when I run the CH the water to the taps keeps hot for longer, however it does still go cold.

Thanks in advance
Tony
ps if it is the diverter valve can I buy a kit to repair it and is it easy enough to repair?

 

[Whitespirit66]

The good news - your diverter is probably OK.

The bad news - sounds like 2 faults.

Try checking the pressure in your expansion vessel, no1 on this link

//www.diynot.com/forums/viewtopic.php?t=37170

You could also try pushing the pin in on the vessel's schrader valve (car tyre type) to see if water comes out. You will probably find that the system is losing water out of the pressure relief pipe. It's the copper pipe that goes from under boiler, through wall to outside.

Also, sounds like your plate heat exchanger is blocked causing the hw to cycle.

 

[toeknee8]

Thanks for your advise, I shall look at the expansion vessel as you suggest tomorrow. If it does not have water come out of it when I press the valve in does that mean it is ok? Will I need to add pressure to it as the water pressure drops to zero over night and I have to top it up every morning, sometimes twice a day if I go out for a few hours. I dont know if this woill cause the pressure to drop in the expansion vessel.

Thanks for your support and advise, it is really appreciated.
Tony

 

[Whitespirit66]

Water from the exp vessel will mean that the vessel needs replacing. If no water, it probably just needs checking and re-pressurising as in FAQs.

Adding pressure won't cause pressure to drop in the ex vessel. This isn't the problem. Basically if the ex vessel isn't properly pressurised, when the boiler is on, the vessel won't absorb the expansion of the system water as it heats. Instead, the expanded water is forced out the pressure relief valve to the outside.

 

[Agile]

You can check that by fitting a plastic bag or condom over the pressure release valve vent.

Are you in Telford? I like the Indian restaurant in the old town run by Anwar!

Tony

 

[toeknee8]

Hi Agile,
Yes I am in Telford but unsure which restaurant you mean as there are a few about here.
I have tried the bag trick but it remains dry so I am getting more worried everyday as I cannot see any obvious signs of a leakage however my rads downstairs are fed from pipes underneath concrete floors Any advise I get is worth persuing so thank you for your post.

Regards,
Tony

 

[Whitespirit66]

Try turning off boiler, pressurise system to 2 Bar, and close the isolation valves where the flow and return pipes (the bigger pipes left and right side) go into bottom of boiler. Leave the boiler overnight.

When you return to boiler, if pressure has dropped, then fault is with boiler. If when you open the valves, the pressure then drops, the leak is somewhere on the system.

 

[toeknee8]

Thank you Whitespirit for your advise. I shall try that tonight, just got my fingers crossed that it isnt a leak underground. If there is a leak can you advise me on how I can locate it?
Regards, Tony