What Do You Do If Your LST Radiator Doesn't Work?

22 Feb 2019

What Do You Do If Your LST Radiator Doesn't Work?

What Do You Do If Your LST Radiator Doesn't Work?

LST Radiators are an important safety aspect in many commercial environments and it’s vital that they are working to their full capacity to keep spaces comfortable and up to the required temperature standards.

If your LST radiators aren’t working, there are several factors that could be causing the fault.

Contour have been blogging about potential causes and what you can do if you do encounter an issue with your LST radiator.

Read on to find out more…

Why Isn’t The LST Radiator Working?

When you realise that the LST radiator isn’t working as it should be, call the supplier and explore the issue with them.

You could send photographs to the supplier of the LST radiator which would help them to diagnose the problem quicker and could lead to a faster solution being implemented.

There are several reasons that could account for why the LST radiator isn’t working. The most common causes of a faulty LST are:


Stuck TRVs

TRVs can get stuck due to their age. Older TRVs sometimes stick which can cause problems with the overall performance of the LST Radiator.

Similarly, the TRV may stick if it hasn’t been used for a long time.

You’ll be able to hear if the TRV is stuck because, when you turn the LST radiator on, you won’t hear water flowing in and out of it. If there’s no sound; a stuck TRV could be the cause.


Incorrect Connections

If the flow and return on your LST radiator is connected the wrong way, the LST radiator will not work.

If this is the case, when you turn the system on, you’ll hear a knocking or banging sound coming from inside the LST radiator.

To fix this, you’ll need to have the flow and returns swapped to the right positions.



If the LST radiator is taking a long time to heat up or has cold patches at the top then this could be a sign that it needs bleeding.

Most LST radiators need to be bled once every 12-18 months to ensure that they are fully maintained and working to their full potential.


Position of The TRV

The position of the TRV head can affect the overall performance of the LST radiator.

If the TRV sensor is inside the cover rather than remotely located elsewhere then it will pick up on the temperature inside the radiator cover rather than in the room.

As a result, the system will shut off because it will think that it’s reached the right temperature while the room is still cold.

Remotely located TRVs will help to prevent or resolve this issue and create warmer spaces.


Contour LST Radiators

Contour LST Radiators are designed to have an expected life-span of between ten and fifteen years.

For added peace of mind, Contour supply LST radiator with a 5-year warranty.

This means that, in the unlikely event of a problem, your heating solution is covered to help resolve the issue and restore your heating system to its full potential performance.



There are many reasons why your LST radiator might encounter a fault that prevents it working to its full capacity.

If you find that there is a problem with your LST radiator you should contact the supplier and describe or provide photographs of the LST to help them to diagnose the issue and offer a quick resolution.

Contour LST radiators are supplied with a 5-year warranty. This means that, in the unlikely event of an issue, it can be resolved quickly and efficiently.

Would you like to find out more about LST Radiators? Fill out the form below to speak to a heating expert today…



About Us

Contour produces a range of innovative, safe surface temperature systems for healthcare, education, mental health, commercial and secure sectors, working in close partnership and collaborating with architects, M&E engineers, NHS Trusts, local authorities, design consultants and contractors to deliver outstanding safe heating solutions.

Contour is the exclusive partner of BioCote® anti-microbial technology for LST and anti-ligature radiators.  BioCote® additives reduce bacteria by up to 99.9%. Contour combine an extensive range of colour-paints is  with BioCote® for a durable, high-quality finish.

Contour’s heating solutions offer secure, single-person quick access to radiator guard interiors for regular deep cleaning and maintenance.  Each year, Contour save the NHS millions of pounds in cleaning costs, therefore delivering cleaner, safer environments.  Contour is redefining the marketplace and therefore many regard us as a design and innovation leader within the industry.

Contour have a quality- first philosophy. Our customer-focused team possess a ‘can-do’ attitude, they take pride in developing solutions for your heating requirements.

Contact us at:

The Mansions, 43 Broadway Shifnal

Shropshire TF11 8BB United Kingdom

+44 1952 290 498


Twitter: @Contour_Heating

LinkedIn: Contour Heating Products Ltd