Why Is Your Indianapolis Furnace Short Cycling?

By: Brian Schutt  |  January 2, 2019

Furnace short cycling is a problem for many Central Indiana home and business owners. If you’re unfamiliar, furnace short cycling is an HVAC term used to describe a scenario when heating and cooling equipment turns on and off too frequently. A cycle is the length of time the system is either heating or cooling the air.

You might hear it turn on, but it turns off before the home is at the desired temperature. The thermostat senses the temperature is low and the furnace kicks on again. Let’s review what causes furnace short cycling and what to do about it.

Reasons for Furnace Short Cycling

The Furnace is Too Big

Your HVAC equipment is one of the biggest investments you’ll make in your home. As a key component to the health, comfort and safety of your household, it should be the right size for your home and your needs. When it comes to a furnace, air conditioner or heat pump, it’s important to perform the correct calculations.

When we consult with Indianapolis-area home and business owners, we evaluate anticipated occupancy and usage. Based on the square footage, insulation, plot, area climate and other factors we determine the most appropriate load for you.

This translates into specific equipment recommendations. Remember, bigger is not always better. A furnace, for example, which is too big for the space will blast out the warm air and heat the home too quickly. As it reaches the set temperature, it shuts off. As your home cools off the furnace repeats the cycle.

Ultimately, this start-stop-start repetition strains your equipment. This strain causes excess wear and tear. After a while, it prematurely ages your system and requires a major repair or even replacement.

If this is the reason your furnace short cycles, discuss it with your Homesense consultant. We have short and long-term options to help correct the situation.

The Flame Sensor is Dirty

The function of a flame sensor is to inform the furnace system if there’s a flame when the gas valve is open. To prevent gas from invading your home, the sensor shuts off the gas valve if it doesn’t detect a flame.

However, when corrosion on the flame sensor is present, the sensor won’t recognize the flame. Because it thinks there’s no flame, it turns off the gas valve, which shuts your system down.

Fix this with a service or maintenance visit from Homesense. Our technicians will clean the flame sensor and prevent the short cycle problem. The sooner the better, to better preserve the lifespan of your furnace.

The Exhaust Vent is Blocked

Occasionally, yard waste or animal nests obstruct these HVAC exhaust vents. Also known as flue pipes, these are typically located on the roof, or can be in a side wall if you have a high-efficiency furnace. The obstruction causes hot gases to build up inside. Once it overheats or senses exhaust air is not leaving the flue, safety features shut the furnace down.

We recommend a visit from our professionals. Especially if your flue pipe is on the roof. We’ll inspect it and if it’s the cause, clean it out.

The Thermostat is in the Wrong Location

If your thermostat is installed in a poor location, it affects the performance of your heating and air system. For example, if it’s on a wall which receives a lot of direct sunlight during the day, it may read the ambient air as warmer than the house as a whole.

Likewise, if it’s located near a heat source it will feel the heat and turn the heating system off. Soon it will realize the house is cool and kick the heat into gear again.

Rectify the situation with a thermostat relocation. If you’re unsure of where to put it or how to deal with the wires, call Homesense at 317-203-8149.

The Furnace Has a Clogged Air Filter

Dirty air filters are the nemesis of heating and air systems everywhere. Clogs in the system, such as a dirty air filter, prevent air from reaching your heat exchanger.

This causes it to overheat and the “limit switch” shuts the heating unit down. It repeats as the system turns on again to try to warm the house to the desired temperature.

At Homesense, we recommend checking your air filter monthly. Change it as needed. For most people every two to three months is sufficient.

Furnace Experts in Indianapolis: Homesense

Short cycling can happen with furnaces, air conditioners and heat pumps. If you experience what you suspect is a short cycle problem, we want to help. If you’re a homeowner in Indianapolis or the suburbs, like Westfield or Carmel, Homesense is available for your heating and air service, repair and installation needs.

Have you scheduled HVAC service lately? If not, call us at 317-203-8149. Our technicians are thoroughly trained and certified to repair any brand. Plus, we encourage you to take advantage of our preventative heating and air service agreement. It’s a great value and convenience.

Call Homesense or submit an appointment request form today.

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