Your home's hydronic heating uses a semi-closed system. Under normal operating conditions, water shouldn't enter or leave, although system pressure will vary with temperature. Since water expands as it heats up, an expansion tank prevents the excess pressure from overloading the system and causing leaks or other damage.

As a result of this design, conspicuous pressure drops are usually a good indication that something is wrong. If you've noticed your pressure dropping or your other issues with your heat, your system might be leaking. If your heating contractor suspects a problem, they'll usually follow these three steps to locate, diagnose, and repair it.

1. Visual Inspection

Sometimes an old-fashioned walkthrough is the best way to detect a problem. Your hydronic system uses pipes that run through your walls, floors, and ceilings, which means a hidden leak can potentially cause damage to other parts of your home. If your contractor believes your system has a leak, they'll often begin by simply walking through your home near radiators or supply pipes for radiant floor heating.

Signs might be obvious, such as wet spots or evidence of mold growth, or they may be more subtle. Sometimes you can detect a small leak by listening for the sound of dripping water or the hiss of pressure escaping from the system. These methods might seem a little outdated, but they're often the quickest way to reveal a problem.

2. Infrared Detectors and Cameras

If a visual inspection doesn't help, it might be time to step up to some more advanced technology. Contractors also often employ these methods when looking for leaks in concrete slabs since water typically won't penetrate through the floor unless the leak is severe. An infrared thermometer — like the kind nurses use to take your temperature — is one easy method. IR cameras can provide even more details.

Your contractor may also turn to these tools even if they find the problem by visual or auditory clues. Cameras and thermometers can help pinpoint the exact location of a leak. This extra information means less demolition work to reach the affected pipes and less disruption for your home.

3. Pipe Access and Repair

Finally, your contractor will need to access the leaking pipe to conduct repairs. Radiant slab heating might require significant demolition, while pipes behind drywall may only require some minor cutting. However, corrosion and other issues may force you to replace more than simply one small section of pipe. In these cases, additional demolition may be necessary to gain access to enough of the system.

Finding a leak in a hydronic heating system can be more challenging than locating other plumbing issues. The best way to resolve these leaks and restore your heat is by working with an experienced heating contractor.