Return Pipes full?

[AlastairK]

Last winter all 5 radiators developed pinhole leaks during the course. I have removed all the radiators and drained the system from the lower stop cock which I found under the floor boards in the hall.

The system is very old and works with an expansion tank which fills it up through a float mechanism. The boiler connected is an old Glow-Worm 25-30B. No hot water attached to this boiler.

I have filled and drained the system about 20 times to remove all the old rust and particles and the water is now emptying clear. Today I started replacing the old lockshields and putting on TRV's. BUT there is water pouring out of the return pipe side of the radiators!?

What am I missing here? Is there a second valve hidden somewhere?

Thanks in advance...

 

[Armo74]

How do you get your hot water? The system obviously hasn't drained properly you could try attaching an outside tap hose connection to the lowest return pipe valve and drain it that way.

 

[AlastairK]

Hot water is through a separate system. I have a Corvec Britony IIA heater which supplies the hot water.

I guess I must have a blockage somewhere if all the water is not being drained from the system from the drain cock. Will try and drain it out from one of the return lockshields.

 

[AlastairK]

Do you think that there could be an air lock created by me taking off the radiators?

Would I need to connect up each radiator feed and return to clear out the system?