DIY Doctor UK DIY Forums

I have two pipes going from 1st to ground floor. I need to take out a section in each (copper) and put in plastic ch pipe thus removing a kink in both pipes. Can I successfully use one of those vacuum kits where one blocks the overflow and outlet of the feed tank in the loft? I want to make sure before I try this so maybe someone has done this. Thanks.

I've been using these kits regularly for over five years now and how found in a majority of instances ther remove the necessity of draining down. The problem is, I have found no way of gauging beforehand how successful they will be. Sometimes the flow stops after about a pint and other times you wonder what's the point. Occasionally the flow won't stop, but it slows enough to allow for a compression coupling.

Here are a few tips I would offer.

1. Don't use a bung in the expansion pipe. Use a Speedfit end cap.
2. Don't work on the flow and return together. Do each at a time. (Breaks the vacuum otherwise)
3. The lower down you are on the system the less likely it will work.
4. Be prepared for a large unexpected flow of water. On one job I thought everything was under control and suddenly...... Luckily I had a thumb and a mate to empty the buckets.

Basically, you are in the lap of the gods.

Have you considered freezing the pipes?

Thanks for replying, I'll try the vacuum method with your advice points. I have to basically swap over some plastic push on fittings. I will remove a lot of the feed tank water and shut off all radiators and have some stop ends in my pocket ready!

There is no need to empty the header tank, it is blocked off anyway.

Just release the pressure in the system before you separate the pipes. Undo a drain vale close to where you are working. This is going to be the trick bit, undoing the first connection. You could get a good spray of water.

I usually just go for it because it is only water at the end of the day but that's just me.... Bear in mind it could be Dirty water. Black water + beige carpets = four letter words.