VIDEO - How to fix a radiator that wont get hot

VIDEO - How to fix a radiator that wont get hot
10 April 2014
VIDEO - How to fix a radiator that wont get hot

We have brand new, efficient versions of the radiator in the video in our Convector Radiator range.

Today we’re going to have a look at the problems you might have if you’ve only got one radiator that’s not working.

So let’s say you’ve got a house full of ten rads and you’ve got one radiator in one of those rooms that just won’t get hot. Usually you’ll find that it’s actually a really really simple solution and one that you can do yourself, without actually having to call a plumber out. So let’s see how we can do that now.

There are two ends to a radiator where the heating will come in and go out. The lockshield end is generally on the return side back to the boiler, so the first thing to do if the radiator isn’t getting hot is to get yourself an adjustable spanner, or a pair of grips, and open the lockshield valve one full turn. Now go to the other end of the radiator and, if there’s a thermostatic radiator valve (TRV) present (which there is on most radiators in the UK), make sure it’s fully turned open.

If you’ve opened the lockshield at one end and the radiator TRV at the other end and the radiator still doesn’t get hot, what you can then do is remove the radiator TRV head. Once you’ve removed the head, that will expose the TRV pin, that the radiator valve acts on.

Now often these can get stuck down in the shut position. To solve this issue, do not use anything to hit the pin with, but instead, grab a set of grips and wiggle the pin up and down in order to free it off.

Once you’ve got that working properly, you should see the pin goes up and down on its own. If you feel like it once you’ve freed the pin, you can spray some lubricant around the pin shaft to try and prevent it from getting stuck again.

Those are the first two points you should try and cover when you’ve got one radiator that isn’t working.

If you’ve done all that - you’ve opened up your lockshield, turned on the TRV and freed up the pin and you’re still not getting any heat or flow through the radiator, then there’s one more thing you can probably do as a homeowner, although it is still quite advanced.

The first thing to do is shut the thermostatic radiator valve and shut the lockshield. Then get a small towel, put it under the air bleed valve and open up the bleed with a radiator key. That will dissipate any pressure that’s in the radiator because no water can now get into the radiator as both of the valves are shut.

The next thing to do once the pressure has been fully dissipated is to remove the whole airbleed assembly itself and put in a connection that will allow you to attach a normal garden hose. (½ inch male to 15mm compression with a small stub of 15mm copper is fine).

Then turn the heating system off, take the end of the garden hose outside and then open up the thermostatic radiator valve. What will happen is a large body of water will come out through the top of the radiator, go down your hose and out into the garden. The reason to do this is potentially the remaining problem about that radiator is there could be an airlock.

Flushing out the flow side through the thermostatic radiator valve will push any trapped air out. Remember, once you’ve pushed any air out, if you’ve got a pressurised system, top up the pressure on the filling loop. Or if you’ve got a non-pressurised system, you shouldn’t have to worry as it will fill up automatically.

Once you remove any slugs of air, you will then need to shut the thermostatic radiator valve and do the same with the lockshield. Also remove your hose and reinstate the radiator with it’s airbleed, so it’s back to normal. 

Turn the radiator back on and with any luck, you should get some heat flowing into the radiator. Alternatively, if this has not solved your problem, you are advised to watch out How To Balance Your Heating System video.

Convector radiators at Trade Radiators


Related posts
VIDEO - How to replace a small radiator with a large one
VIDEO - How to replace a small radiator with a large one
17 January 2023
VIDEO - View all the colours in our cast iron radiator range
VIDEO - View all the colours in our cast iron radiator range
17 January 2023
VIDEO - How to install a radiator under a window
VIDEO - How to install a radiator under a window
17 January 2017
VIDEO - How to install anthracite radiators in different rooms
VIDEO - How to install anthracite radiators in different rooms
9 September 2016
VIDEO - How to install a dual fuel heated towel rail
VIDEO - How to install a dual fuel heated towel rail
22 July 2016
VIDEO - How to hang a radiator in a pub
VIDEO - How to hang a radiator in a pub
23 May 2016
VIDEO - View our Trade Direct heated towel rail range
VIDEO - View our Trade Direct heated towel rail range
11 May 2016
VIDEO - How to bleed a radiator
VIDEO - How to bleed a radiator
4 May 2016
VIDEO - How to install a radiator in a tricky place
VIDEO - How to install a radiator in a tricky place
30 March 2016
VIDEO - How to install a vertical radiator in a kitchen
VIDEO - How to install a vertical radiator in a kitchen
4 March 2016
VIDEO - How to install a radiator in a conservatory
VIDEO - How to install a radiator in a conservatory
11 February 2016
VIDEO - How to connect cast iron radiators together
VIDEO - How to connect cast iron radiators together
20 October 2015
VIDEO - Installing a heated towel rail (timelapse)
VIDEO - Installing a heated towel rail (timelapse)
22 September 2015
VIDEO - How easy is it to move a radiator?
VIDEO - How easy is it to move a radiator?
17 September 2015
VIDEO - Learn how to pipe a radiator
VIDEO - Learn how to pipe a radiator
30 June 2015
VIDEO - Learn how to balance a vertical radiator
VIDEO - Learn how to balance a vertical radiator
23 June 2015
VIDEO - How to hang a radiator on plasterboard
VIDEO - How to hang a radiator on plasterboard
5 May 2015
VIDEO: How to install a Deco Stainless Steel Radiator
VIDEO: How to install a Deco Stainless Steel Radiator
2 April 2015
VIDEO - How to Bleed a Radiator
VIDEO - How to Bleed a Radiator
24 February 2015
VIDEO - Why adding inhibitor is beneficial to your heating system
VIDEO - Why adding inhibitor is beneficial to your heating system
19 February 2015
VIDEO - How to install a column radiator
VIDEO - How to install a column radiator
7 August 2014
VIDEO - How to add inhibitor to your pressurised central heating system
VIDEO - How to add inhibitor to your pressurised central heating system
24 June 2014
VIDEO - How to add inhibitor to your heating system via a loft tank
VIDEO - How to add inhibitor to your heating system via a loft tank
15 May 2014
VIDEO - How to add inhibitor to your heating system via a heated towel rail
VIDEO - How to add inhibitor to your heating system via a heated towel rail
17 April 2014
VIDEO - How to change a thermostatic radiator valve
VIDEO - How to change a thermostatic radiator valve
31 March 2014
VIDEO - How to bleed a heated towel rail
VIDEO - How to bleed a heated towel rail
20 February 2014
VIDEO - How to fix one radiator not working
VIDEO - How to fix one radiator not working
1 February 2014
VIDEO - How to balance your heating system
VIDEO - How to balance your heating system
15 January 2014
VIDEO - How do thermostatic radiator valves work?
VIDEO - How do thermostatic radiator valves work?
28 November 2013
VIDEO - How to install a heated towel rail
VIDEO - How to install a heated towel rail
1 November 2013