3 April 2014
Today we’re going to look at the really simple process of how to bleed a radiator, and in particular, a heated towel rail.
Now usually, we bleed a radiator when we’ve done some work to the system, when we’re filling it all back up or you’ve tightened up a leak (or something similar) on the bottom of the radiator valve and you need to get that all sorted out and refilled properly.
(There are other reasons that we might need to bleed air out of a radiator and the main one is that there’s not enough treatment in the heating system water, but we’ll cover that in another one of our articles.)
It’s a really simple procedure and you’ll know exactly how to do it after reading this article.
So you’ve done all the work you needed to do to your heating system and now you’re ready to bleed the radiators, and in particular, your towel rail.
The first thing to do is make sure the lockshield and the thermostatic radiator valve (TRV), if it’s present, is open.
You will normally have two lockshields on your towel rail and you will need to pop both caps off and open both valves fully in an anticlockwise direction.
Before you let any air out of the towel rail, you must make sure that either the feed, from the feed and expansion tank in the loft, is open, or that you have enough pressure in your system if it is a sealed or pressurised system. You can make sure of that if you go to the filling loop in the airing cupboard (or wherever that may be in your house).
Alternatively, if you’ve got a combi boiler or a system boiler, the filling loop will be inside the boiler itself. Always refer to the instructions on how to repressurise the system, especially if you’ve got a boiler, as you will have to look at their specific way of doing it.
Make sure you have an adequate supply of water to the system and you should now be able to easily vent air from the towel rail. This can be done with a radiator key, which has a very small square in them at the end. But also many bleed valves have a small slot as well, so it’s possible to use a slotted screwdriver instead.
If you are using a radiator key, a small tip is to file off the taper that’s on the inside of the key. The reason for doing this is sometimes you’ll be working on a radiator that’s been painted loads and having the taper on the end of the key doesn’t let you get a grip on the end of the bleed square quite as it should.
What needs to be done is very simple - put a cloth around the bleed valve, slack (loosen) it off, let the air out and as soon as a little bit of water starts to come out, close it really quickly. Fingers crossed, the cloth will catch all the water.
When you start to release the air, you will hear a fairly loud hissing noise as the air escapes. Once this noise stops, quickly tighten the bleed and you can then be confident the towel rail has been bled of air.
So there you go. You’ve read how easy it is to bleed a towel rail of air. All you need is a cloth, a radiator key and a small adjustable spanner (or set of grips) to make sure that the radiator valves are open. This also works for normal column radiators, panel radiators or any type of radiator you’ve got that will take a radiator key or a slotted screwdriver.
You can also view a video
of this process on our YouTube Channel.
The radiator featured in the main image is the Pagini 1200x500mm Contemporary Heated Towel Rail
Article by Benjamin Clarke