Five Causes of a Leaking Boiler

A leaking boiler can cause massive amounts of water damage in the home. Locating the cause and fixing it promptly is necessary to prevent disaster.

1. Faulty Expansion Tank

The expansion tank is designed to safely relieve pressure in the event the boiler overheats. The tank will fill with the steam and water produced in an overheated boiler, then allow the moisture to trickle back into the boiler once pressure reduces. Unfortunately, expansion tanks can develop leaks of their own, either at the connection point to the main boiler or somewhere on the tank body. Repair of the connection or replacement of the expansion tank will be necessary

2. Failed Safety Valve

Every boiler has a safety valve that is designed to allow pressure to slowly and safely escape in the event of a malfunction. The purpose of this valve is to prevent the boiler from exploding due to pressure issues. It's vital that this valve is tested annually to make sure it works properly. If the valve is leaking, either it wasn't shut properly following such a test, or there is an issue with the seals and it needs to be repaired.

3. Abnormal Pressure

High pressure in a boiler indicates a major malfunction. When pressure is building, the boiler may hiss or rumble. Water will also begin to leak from the pressure relief valve. It is best to evacuate the area and call for help while cutting off power to the boiler if it is safe to do so. In some cases, abnormal pressure is caused by a broken thermostat or an overly high thermostat setting. A failed or badly adjusted pressure relief valve can also be the culprit.

4. Pipe Corrosion

The pipes leading into and out of the boiler can corrode or rust over time. When this happens, pinprick holes will first appear. Moisture may seem to condensate on the outside of the pipes due to these small holes. As the holes become larger, the leaks will become more severe. Replacing the pipes is the only possible way to fix the problem.

5. Failed Seals

Various seals prevent leaks where water supply and outlet lines attach. There are also seals at each valve opening on the boiler, as well as seals where two pipes adjoin. Over time, these seals can fail and leaks can occur. If leaking is happening at a joint, then chances are the seal needs to be replaced.

Contact a boiler repair service immediately if you find a leak near your boiler.