Is this my central heating drain valve?

kkelly77

Hi all,

I took a couple of photos (attached) beside my oil boiler located in my shed. Is the valve located beside the white pipe the drain valve for the central heating system? I need to drain the system partially to allow for fitting new valves and radiator upstairs. Thanks for the help.

K

Micky Dolenz

yes

kkelly77

Micky Dolenz wrote: »

yes

Thanks Micky.

I've been tole to open the drain valve and to open a bleed valve on a radiator upstairs to aid draining. What's the procedure for refilling the system?

Micky Dolenz

Should be a filling valve somewhere, maybe in the hot press. You should see a gauge beside it, indicating the pressure in the system.

Or it could be a semi sealed system. Pic of hot press may be a good idea.

kkelly77

Micky Dolenz wrote: »

Should be a filling valve somewhere, maybe in the hot press. You should see a gauge beside it, indicating the pressure in the system.

Or it could be a semi sealed system. Pic of hot press may be a good idea.

There is a small water tank in the attic beside the main water tank (vented system?). Does the water come into the system from here? i.e. no manually refilling required.

Micky Dolenz

You have an expansion vessel beside the boiler which would indicate that it is sealed, yet an feed and expansion tank in the attic which would indicate that it is open vented.

I would open drain off, and see what happens. If tank empties you know your source, if not, it is probably redundant.

kkelly77

Micky Dolenz wrote: »

You have an expansion vessel beside the boiler which would indicate that it is sealed, yet an feed and expansion tank in the attic which would indicate that it is open vented.

I would open drain off, and see what happens. If tank empties you know your source, if not, it is probably redundant.

Excuse my ignorance Micky, but what do you mean by 'redundant'? The system needs to be manually refilled?

Antomus Prime

kkelly77 wrote: »

Thanks Micky.

I've been tole to open the drain valve and to open a bleed valve on a radiator upstairs to aid draining. What's the procedure for refilling the system?

If there's an expansion tank and an expansion vessel then it's prob a semi sealed system.

You need to follow the pipe from the tank into the hot press and close the valve on it. There wont necessarily be a gauge but technically there should be. Once it's closed open the drain off valve and then open all the vents on the rads upstairs. Swap the valves and then close all the vents. Once they are all close , along with the drain off valve, open the valve again and fill up the rads on by one, starting with the downstairs ones because they will probably loose a bit of water even though you didn't vent them. Once this is done you should be fine to fire up the boiler.