If your home uses hydronic heating, you have a boiler instead of a furnace. While hydronic heating systems can be an efficient way to keep your house warm, problems with your boiler can reduce this efficiency and increase your utility bills. A sudden increase in your monthly gas budget may be a sign that your boiler has an issue that you'll need to address.

Unfortunately, not every problem that can reduce your boiler's efficiency will also stop it from heating your home, so you might not realize you have an issue. However, if you've noticed your heating bills creeping up, it may be due to one of these three common efficiency problems.

1. Insufficient Combustion Air

Gas appliances require natural gas and oxygen for combustion, and they need a specific quantity of each to ensure clean, efficient burns. Insufficient air is as much of a problem as inadequate fuel, and it can cause your boiler to use more gas and even wear out prematurely. In a worst-case scenario, a boiler that's not getting enough air may produce harmful amounts of excess CO2.

There are many potential reasons why your boiler may not be getting enough air. For example, you might have a restriction in the intake vent, such as a bird nest or even a dead animal. Faulty flue dampers are another potential issue since they can stick closed and prevent air from moving through the system. Whatever the case, it's best to resolve combustion air restrictions as soon as possible.

2. Faulty Aquastat

The aquastat is a crucial component of any boiler. This device functions similarly to the thermostats in your home, but instead of maintaining air temperature, it monitors the water temperature in the boiler. Aquastats have high and low cut-offs, which engage the burners when the water is too cold and turn them off when it gets hot enough.

A faulty aquastat can allow your burners to run for too long, overheating the water and causing efficiency and pressure problems. At the other end of the scale, a lousy aquastat may prevent your water from reaching an adequate temperature, resulting in short cycling and poor heating.

3. Mineral Build-Up

Your boiler's heat exchanger is where energy from the burner flames transfers into your hydronic heating system's water. Mineral build-up on the heat exchanger can reduce heat transfer efficiency and even cause the heat exchanger to overheat and become damaged. If your boiler heats poorly and costs more to operate, there's a chance you have a mineral build-up problem.

Flushing out a hydronic system isn't always easy, so this is a job that typically requires professional attention. You'll also want a professional to confirm that your heat exchanger isn't already damaged since this can lead to potentially dangerous situations. If you need residential boiler repairs, contact a professional.