Trying to turn off feed to radiators....

[Dazzathedrummer]

Hi,

I took off a radiator to do some decorating, which was fine, but I must have twisted one of the valves as I loosened it as it started to leak from the nut where it joins to the pipe.

The leak gets better if I tighten the nut but doesn't completely stop (a small drip will form over about ten minutes) - I figure that I just need to remove the valve and add new tape to the olive (and/or replace the olive) - this is fine, I've done this many times on the water system, but never on the heating system.

With the heating switched off, I'm still getting water coming through if I open the valve.......how do I switch this off??

In the airing cupboard there is a stop cock (with no hadle on it) just above the water pump.......there is also a second stop cock with a red handle on it - but this looks as if it lets hot water into the hot water cylinder.
Should I turn off the stop cock coming from the pump??.......I didn't want to try it incase it's set to a specific position.

Pic here...
https://dl.dropbox.com/u/20678785/heating.jpg

thanks,

Darren

 

[CBF]

neither turn the main stoptap off on the mains (or tie the ballvalve up on the small tank in the loft) drain the heating fix the problem & refill the heating adding corrosion inhibitor.

 

[rjm2k]

Easiest way is to just drain the whole lot, take it as an opportinity to run some cleaner (X400 etc) through and once that's done empty and replace with inhibitor (X100 etc).

Personally, if you are competent enough I would add TRVs to most rads whilst you are at it (screwfix do one for < £6 at the moment) whilst it's drained down.

It is possible to do what you want by capping off the vent and closing the cold water supply to the heating system, plus probably closing off all the rads valves, but as long as you have an easily accessible drain valve just drain it. Replacing the olive can be a pain though, either use a special tool (expensive), cut it and use a screwdriver to break the rest (don't catch the pipe!) or search the forum/google to find someones method of using pipe offcuts and an old valve to gradually prise the olive off.

 

[Dazzathedrummer]

Easiest way is to just drain the whole lot, take it as an opportinity to run some cleaner (X400 etc) through and once that's done empty and replace with inhibitor (X100 etc).

Personally, if you are competent enough I would add TRVs to most rads whilst you are at it (screwfix do one for < £6 at the moment) whilst it's drained down.

It is possible to do what you want by capping off the vent and closing the cold water supply to the heating system, plus probably closing off all the rads valves, but as long as you have an easily accessible drain valve just drain it. Replacing the olive can be a pain though, either use a special tool (expensive), cut it and use a screwdriver to break the rest (don't catch the pipe!) or search the forum/google to find someones method of using pipe offcuts and an old valve to gradually prise the olive off.

How do I 'cap the vent' - All of what you say makes sense and I will eventually add TRV's to all the rads, at the moment though I just need a quick fix so I can carry on decorating - chances are I'll be putting a different rad on this one when I get to it and all the current fittings are 15mm to 3/4 inch - so it'll need a new valve any way.

 

[CBF]

How do I 'cap the vent'[/quote]

& that is exactly the reason i didn't suggest this

 

[rjm2k]

There will be a 22mm pipe hooked over the F&E tank in the loft, I used a speedfit cap (costs about 2 quid depending on where you get it from) on the end of that.

BE SURE TO REMOVE IT BEFORE SWITCHING THE BOILER BACK ON!

You could try without closing off the rad valves but I found the vacuum wasn't strong enough to keep the water in with just the cap and closed off feed. Once everything is closed off, open the valve you want to change and the water should fairly quickly stop. Plenty of rags/old towels needed to protect the carpet etc.

Your system looks a little different to mine but if you follow the pipe up from the pump, where it tees off and becomes 15mm should be the cold feed for the heating, if that 15mm pipe has a gate valve then that's where to cut the feed.

Note, I'm no expert, just a DIYer so do this at your own risk!

 

[JohnD]

if this is an upstairs radiator, you could do it without a lot of draining down.

Tie up the float in the F&E tank, turn off the other upstairs rads, take off the radiator you are working on, and you can use the troublesome rad valve to let the water out. It will probably be a couple of bucketfuls. You may find that a garden hose tap connector fits on the rad valve, which will make it easier.

When water stops coming out of the rad valve, it is dry enough to work on and put PTFE tape on your olive before re-fitting it fully into the valve and retightening. PTFE is fantastically good for sealing olives.

A bit of water will probably come out of the pipe while you are working, but some old towels and a helper's finger down the pipe should be all you need.

If there is inhibitor in the water (there should be) you can tip the buckets back in the F&E when you're fnished.

 

[Dazzathedrummer]

All very helpfull!

I'll give it a go tonight.

Thanks!!