Finding drain off valve - gravity system

[Panther]

Hi everyone - I'm new member and this is my first post. I'm attempting to drain - what I believe to be - a gravity fed system. There is a tank in the loft, with the cylinder below it, on the first floor.

I can't find the drain off valve under any of the radiators on the ground floor. I'm following the instructions of 'plumerparts' -
youtu(dot)be/rZgOp6cACW4

I've also been recommended to clear the 'sludge', using the "sentinel X400 system restorer".

I would deeply appreciate any help. Thanks

 

[stevetheplumber]

if there isnt one under the rads is there one poking out of the wall outside?if no then you have to drain a rad and drain from the valve

 

[Panther]

if there isnt one under the rads is there one poking out of the wall outside?if no then you have to drain a rad and drain from the valve

Thanks - I can't see one outside. We've had an extension, which protrudes further away from the house, than the last radiator in the house. It's not accessible though, it's being used for storage, so I'm going to move everything out of the way. How would I go about draining through the radiator - how you mentioned - if I can't find the valve there?

 

[PlumbBobBob]

how I drain down when there is no drain off is, I drain down the smallest rad downstairs by closing both valves on it and cracking the nut on the side that has the bleed screw on it. when the rad is empty undo the other nut and take the rad off, closing the bleed screw first then stand it upside down out of the way. you can use a normal hosepipe to drain down with, if you have an outside tap use the hose fitting off that-the screw on bit. you just screw it onto the valve if it is the same size i.e. 3/4. tie up the ball cock in the loft or turn off your mains water.

 

[jonnyswamp]

If you just want to drain upstairs, turn off both sides of a rad downstairs, open airvent to relieve pressure, remove blanking plug, fit a 1/2 MI to 15 mm comp in its place, with a short piece of pipe connected to a hose and then open the rad valves
It's not ideal, but it'll do the job if you don't fancy taking the rad off

 

[PlumbBobBob]

If you just want to drain upstairs, turn off both sides of a rad downstairs, open airvent to relieve pressure, remove blanking plug, fit a 1/2 MI to 15 mm comp in its place, with a short piece of pipe connected to a hose and then open the rad valves
It's not ideal, but it'll do the job if you don't fancy taking the rad off

but this will only work with a more modern type of radiator of course

 

[jonnyswamp]

but this will only work with a more modern type of radiator of course

Yes, the type with the 1/2" female tapping at each end

 

[Subby]

If you just want to drain upstairs, turn off both sides of a rad downstairs, open airvent to relieve pressure, remove blanking plug, fit a 1/2 MI to 15 mm comp in its place, with a short piece of pipe connected to a hose and then open the rad valves
It's not ideal, but it'll do the job if you don't fancy taking the rad off

This is what I do too.

 

[Panther]

how I drain down when there is no drain off is, I drain down the smallest rad downstairs by closing both valves on it and cracking the nut on the side that has the bleed screw on it. when the rad is empty undo the other nut and take the rad off, closing the bleed screw first then stand it upside down out of the way. you can use a normal hosepipe to drain down with, if you have an outside tap use the hose fitting off that-the screw on bit. you just screw it onto the valve if it is the same size i.e. 3/4. tie up the ball cock in the loft or turn off your mains water.

The extension was meant to be a bathroom (replacing the old one) - due to unforeseen circumstances, the job wasn't finished. I think I remember seeing the valve in the old bathroom, but the new bathroom not being completed, the pipes are just protruding out of the wall. I've taken pictures of all of them - 2 sets have CH written on them - I assume, which means central heating. It's just covered with a cap, I assume one pumps water in, and the other lets it flow out? How can I tell, which is which? And after I've drained the system, I'll be placing a valve on it, instead of the cap..

If you just want to drain upstairs, turn off both sides of a rad downstairs, open airvent to relieve pressure, remove blanking plug, fit a 1/2 MI to 15 mm comp in its place, with a short piece of pipe connected to a hose and then open the rad valves
It's not ideal, but it'll do the job if you don't fancy taking the rad off

I don't think i need to, if you read above. Thanks

 

[Panther]

Error

 

[Panther]

if there isnt one under the rads is there one poking out of the wall outside?if no then you have to drain a rad and drain from the valve

....

ive attached the images here

 

[Subby]

It doesnt matter which is which as your new radiator valves should be bi-directional.
Once the system is drained, the x400 can be put directly into the header tank, then you can re fill the system, bleed all rads and clear air locks etc and let the chemicals circulate for up to 2 weeks and then...

Drain down again , fill up without turning boiler on, drain down (cold flush), then fill up again and run the heating until all rads are hot, then drain down again (hot flush). Then you can add x100 inhibitor to the tank and fill up a final time.
Make sure when draining and filling that the boiler is turned off and that any zone valves are latched open.

 

[jtsplumbing]

Is that a gas pipe in photo 2 ??

 

[Panther]

Is that a gas pipe in photo 2 ??

I don't think so, it's a bathroom.

 

[Panther]

It doesnt matter which is which as your new radiator valves should be bi-directional.
Once the system is drained, the x400 can be put directly into the header tank, then you can re fill the system, bleed all rads and clear air locks etc and let the chemicals circulate for up to 2 weeks and then...

Drain down again , fill up without turning boiler on, drain down (cold flush), then fill up again and run the heating until all rads are hot, then drain down again (hot flush). Then you can add x100 inhibitor to the tank and fill up a final time.
Make sure when draining and filling that the boiler is turned off and that any zone valves are latched open.

Thanks for your reply.

In the tutorial I was watching, it said to bleed the radiators whilst the system is draining? Should I bleed them after?

 

[jtsplumbing]

I don't think so, it's a bathroom.

Just because its a bathroom doesn't mean there wasn't any gas sometime in the past ! what's the old lead pipe??

 

[Unregistered]

Just because its a bathroom doesn't mean there wasn't any gas sometime in the past ! what's the old lead pipe??

It's a new build. I think that's where the main water supply for the shower was going to be.

 

[jtsplumbing]

It's a new build. I think that's where the main water supply for the shower was going to be.

Sorry Not got a clear photo ! is it a plastic then ??

 

[Unregistered]

Sorry Not got a clear photo ! is it a plastic then ??

Yes

 

[Unregistered]

It doesnt matter which is which as your new radiator valves should be bi-directional.
Once the system is drained, the x400 can be put directly into the header tank, then you can re fill the system, bleed all rads and clear air locks etc and let the chemicals circulate for up to 2 weeks and then...

Drain down again , fill up without turning boiler on, drain down (cold flush), then fill up again and run the heating until all rads are hot, then drain down again (hot flush). Then you can add x100 inhibitor to the tank and fill up a final time.
Make sure when draining and filling that the boiler is turned off and that any zone valves are latched open.

how would I know it's a bi-directional, and what should I do if it's not?

 

[Panther]

but this will only work with a more modern type of radiator of course

if there isnt one under the rads is there one poking out of the wall outside?if no then you have to drain a rad and drain from the valve

Sorry Not got a clear photo ! is it a plastic then ??

This is what I do too.

I was busy and unable to start the work until now, and when I opened them, no water drained out. I kept looking and found this next to the mains, next to the last radiator in the house that actually works. Does it look right to you? Thanks - much appreciated

 

[JCSPLUMBING]

Go to toolstation and buy this and put in on the lowest point in the system Self Cutting Drain Off Cock 15mm - Toolstation

 

[Panther]

Go to toolstation and buy this and put in on the lowest point in the systemin Off Cock 15mm - Toolstation[/url]

I have one already, but is that where I put it?

 

[JCSPLUMBING]

Is it the lowest point of the heating system?

 

[Panther]

Is it the lowest point of the heating system?

Except the extension - where no water is present - yes. Does it look like it's meant to be where the system should be drained from? Thanks

The extension was to replace an existing bathroom, but due to the person - who it was built for - passing away, they abruptly stopped working on it. It's left us in quite a predicament.