Hydronic (water-based) heating systems are more complex than forced-air furnaces, and common boiler problems may require substantial troubleshooting. Most boiler systems consist of more components and moving parts like valves and temperature controls than furnaces that blow hot air. Due to the complexity as well as the heat and pressure produced by a hydronic system, trained diagnosis and repair by an HVAC professional with experience in hydronic systems is recommended.
There are two main types of hydronic systems: steam systems and water systems. Both can use radiators to heat the home or building, but there are major differences between these systems in terms of problems and diagnosis. For the purpose of this article, we will focus our attention on the water systems and we will discuss the steam-based systems in future discussions.
However, some general guidelines about the possible sources of malfunction or reduced performance may help you communicate the problem to a technician and understand his recommendations.
Here are five common boiler problems most likely to require a service call:
- No hot water. This is a wide-ranging problem that could involve a number of components. A defective diaphragm or an air lock somewhere in the system are common sources. Stuck valves that obstruct circulation are often the culprit. If the system is circulating water freely, a defective or improperly calibrated thermostat could be the problem.
- Leaks. Some of the most common sources include temperature and pressure relief valves opening due to excessive boiler heat or internal pressure, or because the seal inside the valve is defective. A crack in the main boiler is another possibility, as are leaky seals in the circulating pump.
- Unusual noises. Banging or gurgling sounds most frequently result from air in the system. Sediment accumulation in the boiler can also cause uneven water heating that creates steam and generates noise. Another cause may be a defective expansion tank or zone valve.
- Pilot light extinguishing. The thermocouple that shuts off the gas supply to the pilot automatically may be defective. A broken air seal nearby could be blowing out the flame, as well. Buildup of combustion residue in the pilot light may also be a factor.
- Loss of water pressure. Commonly the result of a leak, this could also be caused by a relief valve stuck open, perhaps an indirect consequence of a pressure leak in the expansion tank.
P.K. Wadsworth Heating & Cooling covers greater Cleveland with experienced HVAC service. Call us for fast diagnosis of common boiler problems that may affect home comfort this winter.