Avoid draining down

[georgethedog]

Hi

I have a pressurised heating system. I had a 3 metre radiator in my living room which I replaced with 2 smaller rads at each end of the room. I chased out the floor and used hep2o too connect to the rads.

Yesterday I drained down and hooked up the two new rads filled up and bleed all the rads and ran the system. When the pipes got hot one run of pipe lifted out of the channel in the floor. The pipe is a little too long so I need to shorten it. Didn't seem that bad when it was cool.

The pipe that is too long is the pipe connecting the two new rads together not the pipes that are connecting to the existing system.

If I shut the lock Shields and trv's on both the new rads can I get aways with disconnecting the new pipe and have a bucket handy to catch the water that is in the pipe between the 2 new rads.

I know the you shut the lock shield and trv down you can take the rads off I just wanted to make triple sure before I try and do the reverse.

It took me a long time to drain the system yesterday and I ended up using a bucket and draining from the tails of the old rad. So want to avoid that if possible.

Thanks in advance

 

[oldbuffer]

Call your new radiators Rad 1 and Rad 2. If the flow from the rest of the system goes into Rad 1, then Rad 1 is connected by a single pipe to Rad 2, then the other side of Rad 2 is joined to the return for the rest of your system, then shutting down the valves on Rad 1 and Rad 2 should allow you to remove the single pipe connecting the two radiators with only the water in the pipe to deal with.

You should note that the coefficent of linear expansion of plastic pipe is about ten times that for copper pipe. Assuming a cold temperature of 10 degrees and a hot temperature of 60 degrees, your pipe will expand by 9 mm per metre of length. If you do not provide room for that expansion (and subsequent contraction) you will get leaks from fractured pipe or from broken fittings.

 

[georgethedog]

Cheers oldbuffer

I shut down the rads and have taken 20mm off the end off one of the pipes. Just firing up the system now to see what the expansion looks like. I've got it on a 6.5m run from rad 1 or rad 2.

Ive placed in conduit. Do you think that will be enough room for the expansion?