Moving an inverted pipe loop All aspects of plumbing questions and answers, help, tips and information

[greendog]

Hi, I would like to replace a small radiator in a downstairs bathroom with a towel heater and move it up the wall to sit at roughly 110 cm (bottom of the new towel heater). The radiator at the moment is on an inverted loop and has a drain at the bottom.
My question is, can I just replicate the whole lay-out further up the wall or will that cause problems?
Also, is there a way of constructing a side entry into the towel heater that would look nicer than a loop, as it is now at a more visible height.

Thanks for any help you might be able to give.

[plumbbob]

"The radiator at the moment is on an inverted loop"

Sorry. Don't understand this description. Could you explain more?

[chris_on_tour2002]

can't see why this should be a problem, except with the drain-off cock being further up the wall it will probably no longer be the lowest point on the system. so you may want to run the pipe with the drain off almost to the floor then terminate it with a drain cock. tee in further up the pipe to feed the towel radiator.

failing that you might want to insert a drain point on whatever part of the system becomes the lowest point when you move existing rad (may already be another one somewhere, check first to save yourself some work!)

you may need to use normal non-TRV right-angle valves and invert them if you want side-entry. you don't normally use TRVs on towel radiators for 3 reasons:

- they are designed to dry towels as well as heat the room so you want it hot.

- you want the bathroom to be cosy warm

- usually used as the rad to give off excess heat from pump over-run and to protect boiler from overheating if all other TRVs close over. though another non-TRV rad should be in the same room as the room thermostat.

not sure if you can fully invert TRVs it may affect their operation.

[greendog]

thanks chris

keeping the drain cock low makes sense and would solve the issue of it not looking very good further up the wall.

The existing rad is in an extension and it had to be on an inverted loop (plumbob, that's what the DIY manual calls it I didn't make it up :) ) as all our ground floor is solid. We have another drain cock on another rad in the old part of the house, so I think this drain is solely for this rad.

By TRV I take it you mean thermostatic valves on the rad? the existing rad has one so I was just going to recycle that. Leaving the drain low has opened more options on getting the water to the rad so might not go for the side entry after all.

Although, if anyone knows of a towel heater design that has the water entering the rad to the side at top and out at the bottom I would be very interested to hear from you. Thanks!

[chris_on_tour2002]

thinking about it, you may not need to bother with a drain cock. if the pipes drop down from above and only feed the one radiator then any drain down could be done via the rad valves - would leave a tiny bit of water behind but the pipework would look neater.

TRVs are thermostatic valves - not sure if they work properly upside down due to the way in which they work, using molten wax and a spring to open and close the valve. not sure if gravity would cause the wax to run away from where it's supposed to be.

as i say for a towel rad TRVs aren't normally used anyway.

not sure about side entry towel rails, but they probably exist. try your local plumbers merchant.

[greendog]

thanks for your helpful advice

looked online for towel rads and will maybe use a small designer rad with pipe centres at 75 mm, looks quite neat.

Probably will be back with more questions as the project carries on ...