Changing radiator size - must we drain system?

jenfa

hi all

as part of our kitchen redesign we are going to change the radiators, one we can replace like for like but the other we are going to need to make it smaller so we can open a cupboard door. This means shortening the radiator pipes. The central heating system was pressurised a few years ago and we have radiator valves on each of the radiators.

Is the only option to drain the whole system down? We have tiles behind them that will come off with the kitchen fit but fitter says he is willing to change the rads if exact but not redo pipework. Just when I thought we had everything sorted.

Note to self when we move next time it has to have a decent kitchen in place am not willing to go through this trauma again :rotfl:

thanks for your comments

woodbutcher_2

Altering pipework= draining system.

jenfa

thanks Woodbutcher that's what we thought, we have heard about creating air locks and also about freezing kits do any of these work?

StuC75

Even if you freeze the pipe feeding the radiator to be changed, then you still need to deal with what is in the radiator when it is taken off the wall (you wouldn't freeze all that as well)..

its always best to drain it all off then refill and balance after the work has been done..

jenfa wrote: »

thanks Woodbutcher that's what we thought, we have heard about creating air locks and also about freezing kits do any of these work?

jenfa

thanks Stu, having had the system powerflushed I certainly know what gunk comes out of the radiator ours were black and jelly like, hopefully not this time! Balancing if only! we keep trying but we have 17 radiators and due to an extension on the house prior to us owning it some are rads off rads which makes it harder. We found with some if we turned up one too much the other gets cold. We had a larger pump put it to help but it is still not fine tuned yet.

Thanks for everyone's comments, looks like it will be a plumber job then.

foomanchu

You don’t _have_ to drain, you might not want to if the system has been recently flushed & refilled anyway. Can be done without freeze kit, you do need some confidence in what you are doing though.

Get a couple of quality copper push fit isolators.

Depressurise if it’s a closed system.

Close all valves on radiators/boilers – this will stop water flowing too freely.
On copper pipe use quick twist pipe cutter, then (quickly!) push isolator on the non radiator side. The radiator side pipe shouldn’t have too much water in it with the rad valve closed, but if it’s a long run you might want to use a push fit cap on that side too. Have towel and bucket handy if but shouldn’t spill more than a litre this way, maybe an extra pair of hands to hold a rag over one pipe if need be.

Repeat on second pipe. Then lift out the radiator (with valves closed) full of water, take outside, open valve & drain.

Put in new rad & plumbing, connect up to isolators, open, refill, bleed.

Might not be the *best* way but sure is quick and provides a few moments of excitement!

jenfa

foomanchu thank you, this is what husband has been thinking about doing we might chance it! He has been looking at the push fit connectors sounds worth a try

rockin_plumber

If you are using push fit Make certain you clean all the paint off the pipe back to the copper.


I would suggest using compression really, soldering is better but you cant do this if there is water in the pipe.

Ruski

Nothing more attractive than pushfit on display (sniggers!)

Russ

jenfa

So Russ are you saying that copper pushfit can't be painted afterwards? Seeing as it will be underneath a radiator at 5cm off the ground will anybody really notice especially when they will be distracted by my Wow kitchen!

Rockin_plumber thank you for the advice. As the pipes come through the wall from the loo next door they enter the kitchen about the middle of the radiator all we are thinking we need to do is to cut out a horizontal section and then rejoin the length with the thermostatic valve on.

For the cost of paying a plumber to drain the whole system and set it all up again am beginning to think I will just get an infill panel and a smaller kitchen cupboard be a whole lot less hassle.

Ruski

To be fair, Jenfa, the cuprofit copper isolators dont look too bad, I was imagining plastic....
Paint them if you want to, just make sure you leave the isolator slot free of paint... but more improtantly clean the esiting pipe VERY well before attempting this - a little bit of paint can cause an o-ring to let by and you'll be cursing!

Go for it - it can only add to your book of god/bad experiences!

HTH

Russ