Thanks Nige.
1 new build, this one 3 yr old. What's the f+e tank? Is this the small tank that has the mains/ballcock inlet?
If I connect a hose to the draincock, what will I see in the loft when the system is full? Will the system refill when I bleed the rads?
What causes this...
Apologies if this has been covered. I've searched, but not found anything.
I've been stung by this problem twice now! Different properties, both new.
I've removed a radiator, went through the usual process of draining down, tying up the ballcock in the header tank. When trying to refill...