HeatingWhy Won’t My Furnace Shut Off in Harrisonburg, Va

February 15, 2021by Dev

The cold weather of winter is settling in and your furnace is working overtime. Pay attention, if the furnace does not seem to cycle properly, or satisfy the thermostat, you may have one of the following issues, which needs to be evaluated and corrected by a professional HVAC contractor.  

Mountain Valley Home Comfort has been providing answers to local homeowners in the Shenandoah Valley since 1984.

Undersized equipment

If your furnace is undersized, it will not generate enough heat to satisfy the thermostat. Therefore, the furnace will continue to operate, using much more energy, than it should. This causes additional wear and tear on the system, decreasing the life-span of the equipment.

Mountain Valley Home Comfort will assess the overall output of the heating system, relative to the size of your home. They calculate the optimum size needed for your comfort needs.

Not enough return air

When you turn on your furnace, not only is supply air crucial, but also, return air must find its way back to the furnace. When properly sized, the return air flows back to the furnace, to be heated again, in a continuous cycle. A lack of proper return air can cause inconsistent temperatures; uncomfortable rooms; higher energy costs; and could lead to heat exchanger issues.

It is important not to block return air vents with furniture or obstructions. Crushed or disconnected ductwork can prevent return air from circulating back to the furnace. Inspecting your duct work between maintenance visits can prevent an emergency situation. 

Mountain Valley Home Comfort is your local expert to diagnose and alleviate heating problems.

Not moving enough supply air in Harrisonburg, Va

Much like return air, supply air must be able to circulate throughout the living space for optimum comfort. The effectiveness of your heating and cooling system depends on proper air flow. Damage to supply ductwork can result in less air flow to your home.

If your system includes manual dampers, these can become stuck, restricting air flow. In automatic damper applications, the thermostat changes the position of the dampers automatically.

If you are experiencing low air flow and have automatic dampers, you could have an issue with the damper system. A dirty air filter is one of the most common reasons a home HVAC system does not move enough air. A clogged air filter can restrict air flow causing the system to work harder than necessary, which shortens the lifespan of a furnace.   Dirty air filters are a major contributor to premature heat exchanger failure.

Unfortunately, due to the complex nature of HVAC systems, if your furnace will not shut off, it probably needs to be addressed by a professional. If you attempt to fix them yourself, you may do more harm than good. Ensuring your system is properly sized for your home and circulates warm air effectively are best left to a licensed HVAC contractor.

Contact your local experts at Mountain Valley Home Comfort!

2064 Old Valley Pike
New Market, VA 22844
(540) 740-3844
260 Charles St
Harrisonburg, VA 22802
(540) 433-0106

24-Hour Emergency Service

(540) 592-8612


Proudly meets the HVAC needs of Virginia’s Shenandoah Valley in Shenandoah County, Page County, Warren County, Winchester, Rockingham County, Harrisonburg, Augusta County, and Staunton, and in West Virginia’s Pendleton County, and Hardy County.

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