For the plumbers - draining a sealed system

GreiginFife

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We got a new heating system installed last year, changed from a vented system (that I knew really well as had to drain it several times throughout a renovation) to a sealed Baxi system which has been great.

I now need to swap out a radiator in a downstairs room and been trying to find info on best way to drain a sealed system. The old vented system had a draincock outside that I just opened and away it went but that is no longer connected to the sealed system.

When it was fitted we had an Adey Magnaclean fitted so I am thinking just attaching a hose there and putting it out the front door but will that work? Is it as simple as that?

Any suggestions? Cheers
 

CliveW

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Can you not just isolate the radiator that you are swapping out by closing the valves at each end then opening the bleed valve and gently removing the valves from the radiator whilst catching the water into a container?

 
D

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We got a new heating system installed last year, changed from a vented system (that I knew really well as had to drain it several times throughout a renovation) to a sealed Baxi system which has been great.

I now need to swap out a radiator in a downstairs room and been trying to find info on best way to drain a sealed system. The old vented system had a draincock outside that I just opened and away it went but that is no longer connected to the sealed system.

When it was fitted we had an Adey Magnaclean fitted so I am thinking just attaching a hose there and putting it out the front door but will that work? Is it as simple as that?

Any suggestions? Cheers

Pretty much yes.

You'll need to use a container to catch the last bit of water that's in the radiator you're changing though as your boiler will more than likely be higher than the rad you're changing.

Why has the existing drain off been cut off? Have you tried it?
 

GreiginFife

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Can you not just isolate the radiator that you are swapping out by closing the valves at each end then opening the bleed valve and gently removing the valves from the radiator whilst catching the water into a container?


Thanks but new radiator is wider so tails need to be extended and moved out by some 12” either side. Reason it needs changed is that it is undersized for the room so provides next to no benefit.
 

GreiginFife

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Pretty much yes.

You'll need to use a container to catch the last bit of water that's in the radiator you're changing though as your boiler will more than likely be higher than the rad you're changing.

Why has the existing drain off been cut off? Have you tried it?

Thanks. My alternate idea was to attach the hose to the rad valve that’s being removed and drain it from there out the front door by opening the valve.

The old drain valve was on piping that out plumber said was just completely wrong, that was why the old system kept breaking down. I tried it but nothing was coming out of it. All pipes from the old header tanks were disconnected and removed when the new system went in.
 
D

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Thanks. My alternate idea was to attach the hose to the rad valve that’s being removed and drain it from there out the front door by opening the valve.

The old drain valve was on piping that out plumber said was just completely wrong, that was why the old system kept breaking down. I tried it but nothing was coming out of it. All pipes from the old header tanks were disconnected and removed when the new system went in.

Ah right that makes sense.

Other way to do it, isolate both sides of the rad, remove rad then stick a piece of 15mm copper into the hose and and attach to the valve with a 15mm nut and olive.
 

GreiginFife

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Ah right that makes sense.

Other way to do it, isolate both sides of the rad, remove rad then stick a piece of 15mm copper into the hose and and attach to the valve with a 15mm nut and olive.

I’ve just set it up with the hose on the TRV end in exactly the way you describe. Hose is jubilee clipped to a 15mm pipe which is then in the valve head end. Going to start the process shortly.

The rad going in is vertical so that it can be put out of the way of the window, would it be an issue to put the 8mm on to 15mm so that it looks tidier between floor and rad valves or would 8 to 15 cause an issue with flow? Just not a fan of the look of 8mm sticking 200mm out the floor and the pipe cover snap on thingys look even more naff.
 
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I’ve just set it up with the hose on the TRV end in exactly the way you describe. Hose is jubilee clipped to a 15mm pipe which is then in the valve head end. Going to start the process shortly.

The rad going in is vertical so that it can be put out of the way of the window, would it be an issue to put the 8mm on to 15mm so that it looks tidier between floor and rad valves or would 8 to 15 cause an issue with flow? Just not a fan of the look of 8mm sticking 200mm out the floor and the pipe cover snap on thingys look even more naff.

No it'll be fine
 
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