No HW or CH after drained CH system to fix rad run by Potterton Performa 24

[Mo]

Hi Peeps,

Little stuck, my towel radiator plastic chrome brackets were damaged, so I drained the CH system and removed the rad.

I drained the CH system from the drain in the garden. When i disconnected the silver flexi filling loop on the boiler, there was a lot of gurgling from the Potterton Performa 24 it self - like it was filling up with air or something!!

Then the hot water stopped working -which I wasnt expecting.

Now I have replaced the towel rad, refilled the CH system and bleed the rad. The pressure gauge on boiler is showing 1.4

However I am still not able to get DHW or CH! The burner is not lighting either, even if I request CH system to start or open hot water taps, any ideas on whats going on?

I am suspecting that there is some sort of air lock in the boiler it self, not sure how to release.

I was trying and ended up turning the PRV on the boiler, now the pressure gague has dropped to zero and the garden is soaked from the overflow pipe!!

I have tried to refill the system but water just drops out from the overflow value, I think I have caused another problem and might need to replace the PRV as well.....

Any suggestions on how to get the burner/DHW/CH working again.....

[John Rumm]

Most combi boilers run the primary hot water circuit through the rads until you turn the hot tap on. Then a divertion valve short circuits the primary circuit such that it flows though a plate heat exchanger that heats the incoming mails water for the taps rather than the rads. Hence it can't work unless you have a functional primary heating circuit.

The boiler may have been full of air. Some have a bleed valve internally that can be used to clear this. Others may have a test program that runs the boiler pump without actually trying to fire the boiler, to help purge the boiler.

It sounds like the PRV has got some crud caught in it such that it can't reseat properly. You may need to remove and clean/descale it, or possibly replace the PRV.

Once the PRV is sealing correctly, repressurise and bleed any air from the boiler itself. Then try again.

[Tim+]

If the boiler has lit whilst there is insufficient water in the system it may be that an overheat stat has ?popped?. These usually need to be manually reset by pressing a tiny button on the stat itself.

You?ll need to look at the boiler service manual to identify the location of the stat

Tim