Re: Removing a hydronic towel heater rail help?

You shouldn't need to turn anything off.
The heat source for the hot water will pump the same water that goes round the radiators through a coil/heat exchanger in the hot water tank to heat the water you actually draw off indirectly. This pumped water also goes trhough the rail if either HW or CH or both are on. Your example is how it should be done, many (mine included) are so far from the heat source it's only convenient to put them on the radiator circuit.
Close both valves (you will need to turn E by fitting a valve head (eg the one the other side) or using a spanner.
DO NOT MOVE A, G, F, B, D. A is a plug in case you want to fit pipes from the side.
There should be a bleed screw at the top of the rail. Open this - if a lot off water comes out, you haven't shut the valve(s). Otherwise leave open.
Undo one C with a bucket underneath (on top of a towel to protect the floor). When the water starts to dribble, carry on opening until a useful flow is obtained - you are now draining the towel rail, not the system.
When the water stops coming out, undo it completely and then the other C.
Remove the support fixings and the rail should come away from the wall.
Don't let children play with the valves!
Refit, doing up the C's hand tight plus 1/4 - 1/2 a turn (DO NOT OVERTIGHTEN).
Open one valve - water will rush in and air out the bleed valve, which you have left open.
Shut the bleed valve. There is now water in the bottom of the rail and you are testing for leaks. Assuming there aren't any, bleed all the air out. If there are try a little extra tighten of the appropriate C. If it's a disastrous leak (it shouldn't be) shut the valves, leave a bucket underneath and get someone else to have a look!
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)>
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Thanks very much for all this. Can I be totally sure that I understand the "feed" terminology please.... Ignoring towel rails for the moment, say you just have a boiler, a HW cylinder and a set of normal room-heating CH rads. Then the pump that gets the HW from the boiler pumps it into a 3-way valve that lets the HW go to one or both (or neither - in which case you need the bypass) of: (a) the "HW primary feed" - is this the technical term for the HW cylinder? (b) the "CH primary feed" - is this the technical term for the bunch of CH rads?
So then if you wanted to plumb in a towel rad that came on whenever the HW was on, would you have to supply it by branching it from a point in the pipework that lay between the 3-way valve and the HW cylinder?
Finally (sorry about all the questions, I've never tried anything like this before!) when I put the emptied towel rail back on again, I just turn on the HW pump and bleed at the top until all the air is out - simple as that?
Thanks again Richard
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.