can't drain central htg

[mavryck]

Hi

Can anyone help? had a problem with my central heating and after advice went to change the mid position valve but the valve even thou same make and model i couldn't just change actuator. Therefore i needed to drain system but when i put hose on drain cock water came out even thou all the radiators and the header tank have water in them, it feels like some of the pipes are empty could this also be the reason my boiler keeps switching off.
A problem that i posted yesterday.

Thanks

 

[plumbandplumber]

What happens if you open the rad bleed screws? Does anything come out?

The washer in the drain cock may be stuck. Completely unscrew and remove the drain cock head, and see if the washer comes out. Get a dish/bowl under it first!

 

[misterdubya]

If water is coming out, your draining the heating system. Open the air vents on the upstairs rads - it will quicken the process.

Remove old valve and replace.

Tighten bleed screws and re-fill.

Mr. W.

 

[mavryck]

Hi

Thanks for your replies, If i open bleed valves to rads all of them have water. As for the drain cock i have removed it completely and i get just a few drips.

Cheers

 

[ServiceNumpty]

The washer is stuck in the brass body of the drain off valve. You can remove the washer by use of a narrow screwdriver, and drain the system. You will need some towels and a spare thumb close at hand. The problem will be you will need to replace washer, or the drain valve will leak.