Draining combi central heating with no drain

[karlpestell]

Hi All

I would like to put thermostatic valves onto my rads at home but I can't easily drain the system as there is no drain in the house (the previous owners liked cutting corners).

We have one large rad downstairs with the 2 feed pipes which are coming through the floor and surface mounted. I was thinking of using a self cutting tap to clamp onto the pipe and drain the water from downstairs, Ie that should drain the others upstairs.

First of all, is this feasible? Secondly, I want to put something in place permanently so can easily drain if needed again. I have seen the drain valves but can't see a thermo one, so what would you suggest is the best permanent solution for this?

Cheers. Karl

 

[seco services]

You can use a self cutting drain tap on the lowest pipe then when drained remove tap and fit a soldered or compression drain tap.

 

[thfc191]

Yeah it's possible you can buy a self cutting in tool that people normally use for washing machines and tap that into the pipe with a old towel around pipe drain down with hose then take off self tapping tool and where their is a hole use a pipe slice cut out the whole and use a compression tee or soldered tee and add a drain off valve onto the tee for future reference

 

[karlpestell]

Great, thanks guys!

I will give it a go over the weekend and see how it goes.

Cheers

Karl

 

[ChrisR]

If you don't like the thought of leaving a disc of copper in your pipes, turn a rad off, drain it into a bowl or wet-vac then put a hose on the rad connection. The traditional unions are 3/4" which is the common garden hose connector or washing machine hose size screw-on.

An alternative to putting a drain cock in the pipe is to use a rad valve with a built-in drain off, something like this - there are several patterns:

You only need one drain, so leave your Thermo rad valve the other end.

 

[karlpestell]

Thanks Chris

My only worry is I wanted thermostatic valves to be installed but there are obviously 2 connectors on a rad so could have the drain at one end and the thermostatic valve at the other I guess?

Cheers

Karl

 

[ChrisR]

Yep, you don't want thermostatic valves on both ends of your rads.
If you see which end heats up first, that's the better end for the TRV, but they're usually OK either end.
Mfrs may tell you it makes no difference, but it can, to noises etc.

 

[karlpestell]

Excellent - cheers Chris!

Its something I have bene putting off for ages and finally we are decorating one of the rooms so thought that now is a good time. I think with your idea it will make thing a lot easier!!!

I'll keep you posted on how it goes.

Karl