Heating pipe relocation question for plumbers?

The u turn may be to mitigate the effects of expansion and contraction.

Check to see if that 4 foot wide "U" goes across a doorway or hallway on the floor plan directly above that "U".

You can use 3/4 inch sharkbite fittings for this, but I've never heard of a flexible supply hose being allowed to stand in for a pipe in a hot water heating system.

Now, if this is a house with only one thermostat, then you almost certainly have gate valves on all but the longest radiator loop. These gate valves are called "balancing valves", and their function is to pinch off the flow through the shortest straightest radiator loops to force more water through the longer and more tortuous radiator loops, thereby promoting uniform heating of the house.

If you put another coupla bends in that radiator loop, it's going to offer more resistance to water flow through it, and so you'll have to rebalance the flow of heating water through all of the radiator loops. This would involve closing the balancing valves just a bit on the shorter straighter loops to force more water through the loop that you added the elbows to.

Never saw flex either. You can use Sharkbite fittings and put in a section of PEX too. I did that in a problem area on my system.

I don't see what the problem is with PVC and wood nearby preventing soldering. You cover it up with some wet rags.

Then he can see his situation better than we can, and so it's prudent to leave soldering off the table.

This.

That type of expansion joint is pretty standard on steam systems and sometimes on hot water.

Depends on your skill level. Experienced people can get very close to flammables with no problem. I think he as more concerned about the looping though.

Hi Ed,

So if I hear you correctly Pex can be used for hot water heating feed pipes? If so then I can create a loop of Pex but avoid the area that is causing issues now. That being the case, tomorrow will be Pex purchase day.

BTW - the pipe to be moved is the upper of four layers of copper and pvc pipe so for me even cutting the copper out is going to be difficult.

Thanks all

Yes, 3/4" pex will do the job. I have a section of pex replacing a problem copper line I had originally. Sharkbite fillings are simple to use and hold on both the copper and the pex.

Pex is used in a lot of radiant heat applications. When we renovated our offices, the heating contractor used about 100' of pex for the baseboard heat connections.

I think there is a special type of PEX that is supposed to be used for heating systems. It is called "oxygen barrier PEX" -- there are different types. The difference between oxygen barrier PEX and regular PEX is that the oxygen barrier PEX has a special barrier to keep oxygen from being able to diffuse into the system. When oxygen gets into a closed heating system, it can cause corrosion.

I don't know if it will really matter when all you are doing is putting in a

Plus, this is just based on what I have read since I don't have any direct experience with this. Maybe others here will know for sure if what you should be using is oxygen barrier PEX.