December 13, 2019 • In Heating & Cooling • 4 Min Read

How to Fix Your Furnace if it’s Short Cycling

GEM

By GEM

Your furnace isn’t a bike—it shouldn’t be short cycling anywhere. That is where we come in! Furnaces are meant to come on three to eight times per hour and run for several minutes at a time. 

If your furnace keeps turning off and on, you are experiencing short cycling. Short cycling is when your furnace comes on, runs for a minute or two, and then shuts off without properly heating the house. 

This is an important issue because a working furnace is what ensures that you and your house stay warm, especially this winter season in Rhode Island! In this article, we will explore what to do if your furnace is short cycling. 

WHAT TO DO WHEN YOUR FURNACE WON’T TURN ON

The reason your furnace will not turn on is probably related to a safety device in your furnace that is being tripped, causing your furnace to shut down. Due to the complexity of this issue, repairing it requires a professional, but professional technicians are here to help you find the best solution for you. Here are some of your options:

SOLUTION #1: REPLACING YOUR DIRTY AIR FILTER TO IMPROVE AIRFLOW

If there’s not enough airflow, a high-temperature limit control will shut the furnace off. In order to ensure that air can move freely throughout your furnace, you need to clean or change your air filter. 

Call GEM today, and a technician will be happy to get your filters replaced for you.

SOLUTION #2: REBOOTING YOUR THERMOSTAT WIRES TO FIX A FAULTY THERMOSTAT

Your furnace may be turning on and off again because the thermostat is faulty. If you are comfortable and well-acquainted with electrical systems, here is a quick way for you to see whether a faulty thermostat is causing your issue. It can, however, be dangerous, so we recommend contacting a professional to help determine whether your thermostat is faulty. 

  1. 1. Pop the cover off your thermostat. 
  2. 2. Carefully unscrew the white wire and the red wire and connect them together for at least five minutes. 

If your furnace runs normally without short cycling, you need to replace the thermostat. GEM’s licensed technicians are well equipped to replace your system’s thermostat. Book an appointment today to get your furnace back on track.

SOLUTION #3: REPLACING YOUR FURNACE BLOWER MOTOR

The blower motor in your furnace is a device that turns the fan that circulates and pushes warm air into your home. Without the furnace blower motor, warm air will not be released, and your home will not be able to maintain the temperature set on your thermostat. The high limit temperature control will shut off your furnace if your blower motor is not working properly. If this is the source of the issue, you are going to need to replace your furnace blower motor.

Call GEM today, and a technician will take a look and see if a new blower motor is what you need.

SOLUTION #4: CLEANING YOUR CLOGGED FLUE PIPE TO ALLOW FOR PROPER AIRFLOW

The flue pipe is a component of your heating system that works to ventilate unwanted exhaust and combustion byproducts out of your home. It is thanks to this pipe that accidental fires do not start by way of your furnace. To do so, when there is a problem with the flue pipe (such as blockage), the flue limit switch will shut down the furnace. 

Before calling a technician, you can check to see if this is the issue causing your furnace to short cycle. Here’s how to check for a clogged/restricted flue: 

  1. 1. Carefully go up on your roof to check if there’s air coming out of the flue pipe. It may be hot, so be cautious before touching it. 
  2. 2. If the airflow seems weak, turn the furnace off. 
  3. 3. Pull the vent cap off and look down the flue for any restrictions or blockage, such as debris. 

Hint: The most common cause is critters trying to nest in your flue. 

If it is clogged, debris will have to be cleaned out of the flue. Call a technician today to get it taken care of.

SOLUTION #5: REPLACING YOUR CONDENSATE PUMP TO ALLOW FOR PROPER DRAINAGE

In order for a furnace to work properly, it will produce condensate, water vapor, as a byproduct of combustion. New high efficiency condensing furnaces, called condensing furnaces, run that condensate through a drain tube. If the tube is clogged or the condensate pump fails, the condensate will back up and a safety device will shut the furnace off. 

A GEM technician can replace your condensate pump to ensure that your furnace is draining properly. 

SOLUTION #6: CLEANING OR REPLACING YOUR FURNACE FLAME SENSOR

If you hear the furnace come on for a minute, shut down, then try to come on again three times in a row, the flame sensor isn’t sensing a flame. If a flame is there, then the problem is the sensor. 

If either or these is the case, you will need to have your flame sensor cleaned or replaced by a technician.

SOLUTION #7: REPLACING YOUR FURNACE WITH ONE BETTER SUITED FOR YOUR HOME AND ITS NEEDS

If you recently added new insulation and energy efficient windows, you may have more furnace than house! Believe it or not, sometimes furnaces can be too big. 

The solution is a furnace with a lower heating capacity. Contact GEM to speak to a heating and cooling specialist about what options are best for you and your home.

If one of these problems was causing your issue, we’re glad we were able to help track it down. Now you’re all set and back to normal with a warm, cozy home! 

If these troubleshooting solutions didn’t help you out, or you need more assistance, contact us today, and a GEM technician can give you a hand. 

Featured Related Articles

August 19, 2020 • 7 Min Read

Fall Home Maintenance Checklist 2020

There’s a lot to look forward to as summer turns to fall: leaves will change, football season will begin, pumpkin...

Continue reading

July 20, 2020 • 4 Min Read

Office Safety and Maintenance During COVID-19

Since mid-March, many businesses have closed their office doors and transitioned their employees to working remotely in order to preserve...

Continue reading

March 9, 2020 • 3 Min Read

Maintaining Home Hygiene & Protecting Your Health

With a coordinated response to the coronavirus (COVID-19) underway in Rhode Island and surrounding areas, hygiene lessons from our childhood...

Continue reading

January 28, 2020 • 1 Min Read

The Phase-Out of R-22 and How It May Affect You

If your AC system was built before 2010, chances are it runs on the refrigerant R-22 (Freon). If you’ve needed...

Continue reading