Tuesday 3 October 2017

Why do radiators leak?

Why do radiators leak?

Here at Feature Radiators we realise that an article referring to leaks is probably best avoided for a company selling radiators but we are extremely confident about our range of feature radiators, their quality and our track record in dealing with issues. Therefore let’s grab this ‘leaks from radiators’ subject by the horns and discuss.

Three main reasons a radiator would leak:

·         Inadequate maintenance of the central heating system the radiator is on.
·         A manufacturing fault with the radiator.
·         Incorrect or poor installation.

Incorrect or poor installation

Let’s firstly look at possible installation issues. All our feature radiators come with instructions to install, so the process should be as simple as possible for a qualified heating engineer/plumber. Should your installer have any questions we have a dedicated Technical Manager to deal with any queries.

To start if you imagine you are looking at a radiator….
The majority of radiators will have 4 entry points (holes), some have 6.
Starting at the top, all radiators will have a bleed vent to go in one of those entries and usually on the opposite side at the top a blanking plug. Both of these plugs come supplied from Feature Radiators and those parts will have an O-ring, (ring of rubber or silicone) that when screwed into the radiator forms a water tight seal.

We find that these get over tightened, so the rubber o ring that is present gets deformed due to being compressed too much and that leaves gaps for water to escape, although in very small amounts initially over time the issue worsens. Symptomatic of this is ‘veining’ paint around that part of the radiator or rust runs from that part of the radiator.

With bleed valves and blanking plugs, sound advice would be to screw them in hand tight then one quarter turn more with a suitable tool. Also never use any other sealant when an o ring is present. This will ensure the seal is formed correctly and avoid deforming.
Moving onto the remaining 2 entry points at the bottom of the radiator. In 99% of installations in the UK the bottom entries will be for taking the valves (taps).

When installing the majority of valves offered by Feature Radiators an installer would add PTFE tape (plumbers tape) to the threads of the valve tail, this helps to form a water tight seal between the radiator and the valve, there are a few examples of valves that arrive with their own O ring on the valve tail but the majority require a sealant.

Once the installer has filled each of the 4 entry points of a radiator, so air vent, blank plug and a valve at each entry at the bottom, the radiator is ‘dressed’ but may not be filled with water as other works may be ongoing.

At the end of the whole works to the central heating system and after other relevant chemical cleaning and preparation work in accordance with British Standards has taken place the plumber will fill the system with water and fire up the heating. This gives the plumber a chance to inspect all their joins on the radiator with the radiator under the pressure of the central heating system and the radiator also expanding with the heat and then contracting when the system is turned off, that is always a good test for their seals and allows them to notice any seals that need attention.
Based on a sound water tight installation and good seals being formed the next possible reason for a leak would be poor maintenance of the central heating system.

Inadequate maintenance of the central heating system the radiator is on

Much like a car our central heating systems and radiators require regular maintenance to keep them in top condition. We provide this advice on our Feature Radiators delivery information sheet that every customer receives when ordering.

The plumber will chemically clean the entire central heating system on its initial set up or if work is being done on an older system they will use their professional acumen to decide if that is required, always speak to your plumber if in doubt or you have questions it is always best to check. Once the plumber has successfully filled the system with water and everything is water tight they will add – inhibitor, this is the chemical that stops water rusting through radiators and boilers.

Water in its natural state is very corrosive therefore a chemical is required to counter that corrosiveness. Without inhibitor in your central heating system it can suffer an array of issues and leaks can occur from a variety of places. A qualified heating engineer/plumber will appropriately deal with the relevant chemicals for your central heating system. A good point to remember is making sure inhibitor levels are checked annually, usually you can incorporate that on your annual service. If your radiators have been installed for over a year and then they begin to leak, serious consideration needs to be given to the maintenance they have received in their working life.

A manufacturing fault with the radiator itself

Finally and the I am glad to report (from Feature Radiators point of view) the  least common cause of leaks in radiators we supply are due to manufacturing issues.  As an ISO 9001:2008 Quality Management Systems accredited company we ensure all our manufacturers and suppliers work to the highest possible standards. This means our products are all either batch tested in the factory or pressure tested and/or visually inspected before they are dispatched to customers. In doing so the majority of issues are identified before they are even dispatched to the customer. 

In the unlikely event a leaking radiator is supplied this will most likely be down to a pin hole in the radiator body, faulty weld or joint possibly hidden out of view of the naked eye or under the radiators paint coat preventing it being identified on the pressure test. In any of these eventualities the manufacturer’s warranty would cover a replacement or repair of the leaking radiator to ensure you get the radiator working as it should.


I hope the article has been useful, if you have any further questions or queries on this subject matter or Feature Radiators in general, feel free to contact us on 01274 567789 or email – contact@featureradiators.co.uk