Draining heating system - nothing coming out drain valve

[Augustus]

I need to drain down my vented heating system. Been through all the usual steps - tied up the ballcock, opened bleed valves etc but when I open the draind valve hardly anything comes out.
I'm guessing there's an airlock somewhere but the radiators are fine and Ive bled the pump.

The drain valve is on the pipework coming out of a Rayburn. Ive stuck a short piece of hose on and tried sucking on it - I get a load of water but cant apply sufficient suction to clear all the air out so when I stop the water stops draining as theres still a load of air in there.

Im guessing there must be some kind of pump I can get for doing this?
(Or perhaps I should just get a plumber)

 

[Fluffster]

You can try using mains water to flush it out. Cap off the vent pipe with a push fit stop end and then connect a mains feed to the feed pipe coming from your feed/expansion tank and see if that blows it out of your drain cock.

Pete

ps have you made sure if you have any motorised valves that they are set to manual open?

 

[Augustus]

7

ps have you made sure if you have any motorised valves that they are set to manual open?

Ah haven't done that - could that be the issue?.

Got a grundfos pump up in the airing cupboard. How do I set the valve to manual open?

Thanks,

Jim

 

[Fluffster]

Hopefully near the pump you will see the motorised valves which usually have galvanised steel covers or white plastic
On the side of the cover box will be a metal or plastic lever which can be pushed against the internal spring to open the valve. The lever has a little cut out in the body where it can sit to hold the valve open.

You may have more than one of these unless you have a 3 way mid port valve.

Hope this helps Pete

 

[Augustus]

Update - I opened the motorised valve and managed to drain it eventually. It took about 4 hours - just dribbled out. I opened all the valves on the upstairs radiators bur didn't make much difference.

I'm obviously missing something but don't know what. Got to do it all again next week as the radiator valve I was replacing was wrong size (imperial radiator)

 

[HERTS P&D]

Fit a new drain cock, your one must be blocked with the washer.

Andy

 

[ianmcd]

Fit a new drain cock, your one must be blocked with the washer.

Andy

As Andy says the washer in the drain cock will be stuck this is a very common problem so I would replace the drain cock while you are there they are not expensive

 

[Augustus]

Thanks for the replies. Will have a look into it at weekend.

 

[Galoka]

I hate drain cocks, they fail, leak, take for ever to drain down. When I installed the CH in the old house I put in a Tee with a lever ball valve on. Much better (though you do need some where out of the way or where you don't mind the bulk of it as it's not as neat as a drain cock)

 

[Augustus]

I hate drain cocks, they fail, leak, take for ever to drain down. When I installed the CH in the old house I put in a Tee with a lever ball valve on. Much better (though you do need some where out of the way or where you don't mind the bulk of it as it's not as neat as a drain cock)

The problem I have is that mine is obviously so bunged up that I don't have enough pressure to drain more than about half of the system.

If I yank the old one off, is water going to uncontrollably spurt everywhere?

It's not located in the most accessible place - next to the Rayburn in a recess so I can't stick a decent size container under it to catch anything.

I guess I can try and ram a hosepipe into/onto whatever is left once the draincock is removed.

Is there any way I can stop the water from draining out when I remove the drain valve - like keeping the motorised valve closed etc?

 

[Galoka]

Didn't you drain it down again, would have been easiest to do something about it then? if you need to drain down, closing all rad valves will limit the amount of water you have to remove (from in the rads, and also it will stop water from draining from all the pipes.)

You either need to replace the washer in the draincock - you need to remove the screw out plug and the washer goes on the end, though the old one has probably got stuck inside. water will come out of the hole doing this. Or you will need to replace the whole thing.

Thoughts:

1. Can you get a container under the draincock, and bodge up a hose/plastic pipe whatever into the side of the container to drain outside?

2. I suspect there isn't enough space - but if there is is use a pipe freezing kit each side of the draincock.

3. drain most water via a rad. Attach a drain hose to the bottom of a rad. - have ready a length of hose attached to a 1/2" BSP male connector. Close both valves down, disconnect the valve at one end, and drain out the water from a the rad (probably need to use a smaller container to decant into a bucket)
. Connect the hose pipe into the bottom of the rad, open the other rad valve and let the water drain out.

4. Put in a new drain cock somewhere else on the system - maybe a again with a freezing kit.Even if this can't be located to drain the whole system, you could drain most, and then only have a bit left to drain out at the draincock

 

[Augustus]

Didn't you drain it down again, would have been easiest to do something about it then? if you need to drain down, closing all rad valves will limit the amount of water you have to remove (from in the rads, and also it will stop water from draining from all the pipes.)

You either need to replace the washer in the draincock - you need to remove the screw out plug and the washer goes on the end, though the old one has probably got stuck inside. water will come out of the hole doing this. Or you will need to replace the whole thing.

Thoughts:

1. Can you get a container under the draincock, and bodge up a hose/plastic pipe whatever into the side of the container to drain outside?

2. I suspect there isn't enough space - but if there is is use a pipe freezing kit each side of the draincock.

3. drain most water via a rad. Attach a drain hose to the bottom of a rad. - have ready a length of hose attached to a 1/2" BSP male connector. Close both valves down, disconnect the valve at one end, and drain out the water from a the rad (probably need to use a smaller container to decant into a bucket)
. Connect the hose pipe into the bottom of the rad, open the other rad valve and let the water drain out.

4. Put in a new drain cock somewhere else on the system - maybe a again with a freezing kit.Even if this can't be located to drain the whole system, you could drain most, and then only have a bit left to drain out at the draincock

Yes - 3) looks like the way to go. I could go 1) but I wouldn't be able to get a very big container in there & I wouldn't have the confidence that it would drain fast enough to stop the container from overflowing.

If I have to remove the whole drain valve, are they easily removed? I'm guessing it was stuck on their via use of a blow torch...

 

[Galoka]

How much space have you got? you need to be able to pull at least one pipe out of the fitting. If it's soldered then you would have to heat with a gas blowlamp/torch and then pull apart, then clean up the pipes.

Alternatively, cut the pipe each side, put a new draincock fitting in and a short length of pipe and coupler.

If the daincock is at the back of an alcoe, I'd be tempted to put in a Tee, and bring a stub of pipe out to mount the drain cock (or something better) on the end

 

[Augustus]

How much space have you got? you need to be able to pull at least one pipe out of the fitting. If it's soldered then you would have to heat with a gas blowlamp/torch and then pull apart, then clean up the pipes.

Alternatively, cut the pipe each side, put a new draincock fitting in and a short length of pipe and coupler.

If the daincock is at the back of an alcoe, I'd be tempted to put in a Tee, and bring a stub of pipe out to mount the drain cock (or something better) on the end

Very little space. It's next to the Rayburn which has all been boxed in. If it involves cutting pipes I may just leave it. Must be an option to stick a new draincock somewhere else?

 

[GasBod]

Either fit a new cock washer or one of these http://www.heatandplumb.com/acatalo...m=GoogleBase&gclid=CLPTyt3fp7sCFRMRtAodrFcACQ