When a heating system “short cycles,” that means that the system runs for only a brief period before shutting off, typically before reaching your desired temperature on the thermostat. If your heater short cycles throughout the day, it could increase your energy bills, fail to heat your home evenly, and accumulate wear and tear faster.
If you do a quick Google search, you’ll find that a common answer as to why heaters short cycle is incorrect sizing: the heating system is too big for the home. While an oversized heater can be a factor, an appropriately-sized heater can also short-cycle for the following reasons:
1. A Dirty Air Filter
A dust-coated air filter will inhibit airflow through your system. This can cause heat to build up in your furnace. Eventually, a safety mechanism called the fan limiter will shut down your heater to prevent overheating and fires. This causes an abrupt end to the heating cycle.
2. A Blocked Flue or Vent Pipe
Gas, oil, and propane furnaces produce some harmful gases as a byproduct during the heating process. Your furnace keeps these gases separate from your breathing air and disperses them outdoors through a flue or exhaust vent.
Sometimes, things like ice, bird nests, or animal carcasses can clog this vent, allowing flue gases to build up in your heating system. When this happens, a safety mechanism called the flue limiter will shut off your system to prevent any further buildup of toxic gases.
3. A Corroding Flame Sensor
Your furnace’s flame sensor is another critical safety feature. If it can’t detect a flame in your furnace, it stops the flow of gas to the equipment and shuts the furnace down. Without a flame to burn fuel, you can end up with a huge concentration of flammable gas in your furnace that is liable to explode. The flame sensor prevents that dangerous gas buildup from occurring.
Problems arise when your furnace’s flame sensor either gets too dirty or starts deteriorating. Dust buildup and corrosion inhibit the sensor’s ability to detect flames. That means that even if there is a flame safely burning in your furnace, the sensor won’t sense it and will shut your system down. Routine maintenance can help keep your flame sensor clean, but if the part has started to corrode, you will need to replace it.
4. A Damaged Hot Surface Igniter
Most newer furnaces ignite either with an intermittent pilot light or with a hot surface ignition system. In a hot surface ignition system, a component inside your furnace gets so hot that it allows gas to ignite. If the hot surface igniter in your furnace is malfunctioning, the equipment will shut down to prevent gas from accumulating inside of it.
Trust the Dallas technicians at Rescue Air Heating and Cooling to get to the bottom of your heating system’s issue. For fast and fair service, contact us today: (972) 201-3253.