Re-filling heating system big problem

Hi

Please can anybody offer me some help here?

I drained down out heating circuit from a drain-cock to add a new radiator (old one was removed and new one is different size / type so had to cut into pipe).

On re-filling, I untied the float valve and the header tank filled but then it got very slow.

The 3 port was manually opened to it's mid position and I undo radiator ents and manual air vent in loft to try and help it along, but the float valve is only a filling with a very slow flow, so why is the system not re-filling properley. At this rate it will take 2 days to re-fill!!

My hot water cylinder, 3 port vale, pump and manual air vent are all in the loft btw just below the cold water tank and smaller header tank.

Please help

float valve has a lump of grit lodged in the seating

clean it out

better still change it

No the float valve is fine. It lets water in as normal untilt he header tank is full. But the header tank shouldnt be full as the system should be filling via the feed pipe to it from the tank! ANd the feet outlet s not blocked I have checked.

jackcole said:

but the float valve is only a filling with a very slow flow,

Click to expand...

part blocked cold feed

prob where it joins the system

I touched the cold feed pipe with a magne and no sticking though.

Do you think it may be an airlock issue, my system is very old by the look of it.

Could be a blockage on the cold feed. Could be an air lock.

Use a hose off the mains and backfill the system through the drain cock.
Keep an eye on the f&e tank and stop when the water rises either through the cold feed outlet or the through the open vent.