No pressure after draining???

busterjones

Builder hit a heating pipe and to fix it had me drain the central heating.

It's a very old house and heating set up but I expected that it would refill from mains once water was back on.

Boiler is a glowworm 35hx, and it has no valves or anything to allow me repressurise.

One gas in and drain out.

Has water in and out on top including the following:

Pressure has read zero since I switched water back on yesterday.

It's a big house over several floors and only the basement level, which is at same level as the boiler, has any heat. Other rads, when I bleed them have no water I.e. I can remove the bleeding valve.

I assume it should refill from the attic. Its a long time since it emptied but last time, when something popped during heavy frost, it refilled without me doing anything bit I'm not sure how long it took.

House was in flats, and we have 6 cylinders! It's air lock hell everything I need to switch the water off. Cleared all of them yesterday with series of hoses I have at this stage, but could the heating have similar issue I.e. air locked?

I use mains to clear the other locks, is there a way to do the same with the heating, or a way to manually fill e.g. by disconnecting a rad and connecting a hose?

The attic looks like this btw, I believe I know which is the heating feed but I'm just assuming that as it connects to the header tank and has a feed in to it from one of the tanks:

I've tried bleeding radiators - there are approx 20 over 4 floors. Some air in one or 2 but no improvement. Some I can't open as they valves aren't standard size.

Any suggestions on what else I might try please and if there's a way to manually fill and also to clear any potential air locks?

Thanks 👍

Lenar3556

Is the red valve at the bottom of the small expansion tank open? Is the tank full of water? Is there a build up of sludge at the bottom of the tank which is preventing water leaving the tank and filling the system?

Is it definitely an open vented system filled by this tank? I notice a pressure gauge at the boiler which wouldn’t typically be fitted to an open vented system?

busterjones

Thanks @Lenar3556 - tank has water and the valve is open. I'll check if it's blocked.

Plumber told me before that it should refill automatically and with tank there etc I assumed it was open vented system.