Is your central heating system dropping pressure? You might have a hidden leak!

Water leak detection and repair specialists.


Our Central Heating Leak Detection service brings you cutting-edge technology to identify and address hidden leaks, ensuring the optimal performance and longevity of your heating system.
Central heating leaks, boiler losing all pressure, mains leaks, awkward hard to find leaks. Our engineers carry extensive equipment including acoustics, trace-gas, thermal imaging and moisture meters.
For people using Insurance and their trace and access policy we will investigate, access and fix your problem leak, providing a full report for your Insurance company afterwards.
Designed for people who suspect but are not definite they have a leak. We will rule in or out a leak on your pipework and either continue with a full survey or point you towards another solution.
We offer a full homebuyer pipe survey report to anyone who wants to check the property they are buying.
We are appointed to find and fix leaks on some of the most prestigious commercial buildings in the UK. You will have a dedicated point of contact within the office and the same engineer will deal with all your leaks within a set geographical spread.

About Harmuns

We are a specialist non-invasive pipe and water leak detection company here to fix your problems. We find hidden leaks on central heating systems, water mains and hot & cold water supply within the property.

Green Harmuns van

Why Harmuns

  • Excellent customer service. 
  • Vastly experienced and highly qualified engineers. 
  • No find no fee on a verified leak. 
  • Gas safe engineers who can legally work on boilers. 
  • Simple transparent pricing.  
  • No credit card details or deposits taken up front. 
  • No mark up on materials. 
  • No hidden costs. 
  • 12 month guarantee on all our work.

We believe in customer satisfaction. 

From the first phone call to the last and throughout the entire visit the level of customer service was excellent. It was a relief to have a technician with so much experience and expertise attend the house to find our mysterious leak. Will definitely call-on again if and when we experience any more problems.

Harry M

Harmuns really led the way on a 10-bedroom property that had bamboozled other firms. Despite the complexity, they clearly and concisely worked out what was wrong and planned out a successful course of action. They are our go to when we need specialist leak detection.

Chris Fraser
Coombe Residential specialises in the luxury residential market across south west London.

We found Harmuns on line and were so glad we did. We had a suspected leak under the tiles in our hallway/kitchen floor. The team were friendly and efficient; the issue was investigated thoroughly, located and repaired promptly. Highly recommend this company.

Rose A
Fulham, London

I was very impressed with the end to end customer service of this job. From the fast and attentive service from David initially to discuss the work and then Pete’s diligent hard work across 1 and a half days to identify and then fix the leak. Pete was respectful of our working from home and facilitated conversations when it was convenient to do so. He explained his findings every step of the way and tidied up well after the work was completed. I hope never to need their services again (!) but I can at least have the confidence that if we get a leak in the future we are in excellent hands.

Adam S

I couldn’t recommend Harmuns more highly. We had damp issue which pointed towards a burst or leaking pipe and we engaged Harmuns to carry out a water leak survey and possible fix. Stephen the engineer who carried out our trace and access investigation could not have been more thorough; he went above and beyond to find the cause of our issue. From start to finish Harmuns team were friendly, professional and extremely knowledgeable. We will be using them for any similar issues going forward.

Sean H.
Brixton, London

Excellent service. The engineer was prompt and thorough and was very reassuring. He located the leak and was able to access and fix it with the very minimum of damage, leaving the house clean and tidy and advising us how to dry the affected area. He checked the heating system was working properly and there were no further leaks before leaving.

Judith H.

Why Choose Us

From our blog

Contact us for hidden
leak detection!

We fix the leaks
that you can't find

We are not an emergency plumber. If you have a visible leak, please contact your local plumber.