Replace a locksheild or valve - No draintap

[cnb23]

Hello,

I am having a nightmare with radiators that I am hoping you can help with. I need to replace two radiators in the house, this I can (hopefully) do but will need to drain down our open vented system. I have checked all the downstairs radiators and we do not have a drain valve on any of them.

So I need to add a drain valve somewhere, I assume the best place would be to just replace a locksheild or valve on a downstairs radiator with one that has a drain attached? Can I do that without draining the system? Is there anything else I can do?

Would it be crazy to just cut a pipe and quickly stick a hose on it to leak outside the house. Once that has been done the system would technically be drained and I could add the drain valve and two radiators at the same time?

I am happy to go with pipe freezing and work quick, I'm just not sure of the best way forward!

Cheers,
Chris

 

[muggles]

Are the new rads the same size as the old ones?

 

[45yearsagasman]

It can be done by isolating and removing a rad and drain via the rad valve with a hose attached. You don't say if they are ground floor rads or 1st floor. Either way that's a simple method. I would also look outside the property and see if there isn't a drain cock for the heating. It's not uncommon to find it's been done that way. DIY freezer kits are poor imo. If rads are same size there's normally no need to drain.

 

[cnb23]

Thanks for you replies.

The new Radiators will be different sizes. Both are currently twin entry valves (which is why I am changing them) so will need to mess about with the pipe work, both will be on the first floor.

With regards to adding the drain tap I can do that anywhere. My plan was the porch on the ground floor so I could get the water out quickly

How do you isolate a radiator valve? Is there any difference in difficulty in replacing a lock shield of the valve?

 

[Tay7]

How do you isolate a radiator valve?

You turn it off.

With that question, do you think you ought be doing this work yourself?

 

[Whitespirit66]

If you have any valves that are joined to rad tail with the larger 3/4" union nut, you could turn off both valves on a rad, drain and remove rad, then attach a washing machine hose to the union on valve that's left on pipe. Then open valve to drain system out through w/m hose.

Or, you could bung the small F&E tank to create a vacuum in the system. This will allow you to change rad valve without draining.

http://www.diy.com/departments/dray...44_BQ&ef_id=VnsK2AAAAFGzi0DT:20160205154509:s

When draining a system like yours that probably has 2 or 3 port motorised valves, I like to latch the lever(s) on the sides of these to make sure of complete drain down.

 

[cnb23]

How do you isolate a radiator valve?

You turn it off.

With that question, do you think you ought be doing this work yourself?

Haha Fair comment. To be honest I did think it may be a stupid question but thought i had better ask incase i had missed something. Believe it or not I am a competent DIYer. I have fitted my own kitchen (including the plumbing in of the sink) and will do my bathroom in a couple of weeks. The heating side of things is a bit new to me though, especially in an open vented system so thought I would ask as many (stupid) questions as possible.

Unfortunately our pipes are 8mm which seems to make things more difficult. Lots of self cutting drains for 10 and 15mm!

 

[JMGas]

Tie up the ball valve in F+E tank so water cannot fill.
Isolate both ends of one radiator.
Crack the nut on one end and drain the radiator.
Once the radiator has drained, fully open the nut you cracked open.
You may need to loosen the bottom nut of the valve, twist it round so you can attach a hose or aim it into a bucket
Open the isolation valve.

Once fully drained put in a radiator valve with built in drain point.

 

[Tay7]

How do you isolate a radiator valve?

You turn it off.

With that question, do you think you ought be doing this work yourself?

Haha Fair comment. To be honest I did think it may be a stupid question but thought i had better ask incase i had missed something. Believe it or not I am a competent DIYer. I have fitted my own kitchen (including the plumbing in of the sink) and will do my bathroom in a couple of weeks. The heating side of things is a bit new to me though, especially in an open vented system so thought I would ask as many (stupid) questions as possible.

Unfortunately our pipes are 8mm which seems to make things more difficult. Lots of self cutting drains for 10 and 15mm!

Fair play. You dont know til you ask or have a go.

Strictly speaking turning the valve off isolates the radiator and not the valve anyway. Perhaps I shouldnt be giving advice.