At Your Service Plumbing, Heating & Air Blog: Archive for February, 2020

Common Causes of Furnace Short Cycling Issues, Part 1

Tuesday, February 11th, 2020

The last thing any homeowner wants during the cold Utah winter period is a malfunction in their furnace, and one possible such issue is known as short-cycling. Referring to issues with a furnace that is not turning on and off appropriately, short-cycling can be caused by several different possible culprits, and will bring results that range from limited heating capability to major stress on the system that causes it to wear down much faster than usual.

When you visit the pros with At Your Service Plumbing, Heating & Air, we’ll provide the kind of furnace repair and upkeep services that prevent short cycling and all other potential issues from taking place within your furnace and overall HVAC system. If you’ve never dealt with short-cycling before, this two-part blog series will dig into what it is and its numerous different potential causes, plus how you can ensure your furnace isn’t at risk of any of these.

causes furnace short cycling

Short Cycling Basics

As we noted above, short cycling is a condition related to the on and off cycles of your HVAC system. When a furnace is short cycling, that means it’s turning on and off far too often, way more frequently than a normal system would be. In many cases, it turns itself on and then off again so quickly that barely any heat is actually provided to the home before it shuts back down. As we also noted, this can lead to not only poor heating and an uncomfortable home, but also major strain on the HVAC components involved that often causes a need for earlier replacement.

Our subsequent sections will dig into the common reasons for short cycling, plus how you can prevent their risks.

Overheating Issues

The most common cause of furnace short cycling, and one that may play a role in certain other sub-causes as well, is the furnace attempting to protect itself from potential damage by turning off ahead of time. When furnaces overheat, they risk cracks in the heat exchanger, which can spread harmful carbon monoxide gas – the furnace is built to protect against this.

For this reason, the key to preventing short cycling is avoiding factors that lead to furnace overheating. The most common such factor is restricted air flow, whether due to poor ventilation or some other cause.

Furnace Filter Clogging

One such potential cause of restricted air flow: An HVAC filter that has gone too long without being changed or cleaned, and is therefore clogged and blocking air from flowing properly. This prevents air from returning into the furnace, which will overheat it and cause it to turn off. Filters should be replaced regularly to avoid this.

Flame Sensor Malfunction

In other cases, the flame sensor or flame rod in your furnace will shut off almost immediately after lighting. This tends to relate to issues in the inducer motor, where flame sensors do not properly register a flame and shut off the gas valve prematurely. Our team will be happy to clean or replace your flame sensor if we discover this is the cause of short cycling.

For more on the potential causes of furnace short cycling, or to learn about any of our plumbing or HVAC services, speak to the staff with At Your Service Plumbing, Heating & Air today.

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