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


Harmuns engineers only carry the latest, best equipment available on the UK market.

The best equipment

At Harmuns our engineers only use the latest, best equipment available in the UK market. However all the equipment in the world won’t help if you don’t invest in people and training, which is why our engineers as standard are time-served gas-safe heating engineers. This means that they are already incredibly skilled and experienced. Being a good leak detection engineer means having the fortitude, tenacity and doggedness to keep on searching. To trust the process and the equipment. Having the best engineers and equipment means that we are always striving towards the perfect result every time.

Our engineers carry a multitude of very expensive, specialist equipment: trace gas, acoustics, moisture meters, thermal cameras, hygrometers, pipe locators, salt analysis & endoscope cameras. Each piece of equipment helps identify a leak. Our engineers look at it as building the evidence, trusting the process and believing that with enough patience they will be able to find that elusive leak.

Trace Gas Detection

Great for detecting hidden leaks. You drain the heating or hot and cold pipework and put tracer gases into the system and find the area with the highest concentration of escaping gas. This along with evidence from other equipment can get you very close to the leak area.

Acoustic Detection

Specialist acoustic detection equipment is great for picking up the sound of leaking underground pipework. Our equipment is incredibly sensitive. The gentlest of inaudible taps on a table, sounds like a banging drum with a headset on.

Thermal Imaging Cameras

Thermal Imaging Cameras will pick up heat traces and thermal anomalies within the property. Used correctly and along with other detection equipment, can get you remarkably close to the leak area. 

Moisture Meters

Moisture meters are extremely sensitive and a must for leak detection. Moistures meters will find areas of moisture which the naked eye can’t. This can give you some great evidence along with the other equipment to find a difficult leak.

Borescope Cameras

A borescope camera is a great way to see behind and under things. We can take screen shots of what’s showing on the large colour monitor. The camera we use has 3 lenses, facing forwards, left and right so the engineer can easily toggle between the views, giving a wider scope of vision. 

Salts Analysis

When water from the ground leaks into a space and then evaporates it will leave behind chloride salts and nitrates. Our salts analysis kit enables us to take samples and test for the presence of these salts on walls, flooring, wallpaper and plaster.

Pipe Locators

Pipe locators can find pipes and cables down to a depth of 10 metres. Extremely sensitive and highly accurate. They are particularly useful finding the mains water that comes into the property from the street.


Hygrometers measure the amount of water vapour or humidity in the air. It’s good for getting a snap picture in an enclosed space such as a cupboard. It’s not infallible, but it combines with other equipment to suggest where a leak is.

We have tried for 4 months to locate the cause of the damp patch with many different ‘experts’ telling us different things. David in the office was so helpful and arranged for the leak detection engineer, Peter, to phone me and advise me. Peter arrived today at 9am promptly and had found the small, slow leak within an hour. His work was careful, neat and the repair perfect. I would recommend Harmuns wholeheartedly. Very professional, excellent value and such helpful people.

R Harris

Why Choose Us

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.