A combi boiler turns itself on and off to preheat water so that you’ll have hot water when you need it. However, if your boiler ia turning on and off every few minutes, you have a problem. Below are some of the reasons your boiler in Homer City, PA, might constantly turn on and off.


Boilers keep a small amount of water in the heat exchanger to ensure that you have hot water when you need it. If the small water reservoir starts to cool, the internal thermostat instructs the boiler to heat the water again. Once the water reheats, the boiler will turn off until the next time the water cools and needs reheating.

Short-cycling occurs when you have an oversized boiler. If your boiler is the right size, short cycling won’t occur and your heat exchanger won’t overwork or consume more than the needed energy.

Damaged Valve

The temperature control valve regulates the temperature of water in the boiler. If this valve breaks, the boiler doesn’t regulate the water temperature. This leads to extremely high temperatures, which can result in the boiler shutting off automatically.

If the valve closes and limits the flow of water in the boiler, it’ll shut off. Some valves are outside the boiler while others are inside. A professional can help you inspect them.

High or Low Water Pressure

If the pressure of the water is too high or too low, the boiler will shut off. When turning off, the boiler will show a code that a professional can help you decipher. Low water pressure will likely result from a leak in the system that needs immediate fixing.

Other factors that can cause the boiler to turn on and off include a damaged heat exchanger, a faulty thermostat and a malfunctioning heat pump. Call Miller Plumbing & Heating today for water heater maintenance and repair in Homer City, PA.

Image provided by iStock

Pin It on Pinterest