What Should You Do if Your HVAC System Isn't Pumping out Heat for Your Home?

Technician performing maintenance on a furnace - Williams Comfort Air Heating, Cooling, Plumbing & More

No heat is a cause for panic among Indianapolis homeowners, but it doesn’t always mean a big, expensive problem! If you experience heating system troubles, walk through our No Heat Checklist to troubleshoot potential issues before you call Williams Comfort Air for assistance.

If these heating system troubleshooting tips do not restore warmth in your home and you are truly without heat, call us right away. We offer 24/7 emergency service to resolve no heat issues in order to keep your family safe and warm this winter.

The No Heat Checklist

Heating system issues that leave you with no heat are sometimes the result of simple errors. These things can often be resolved by the homeowner without professional help. Not only does this save you the cost of a service call, but helps you rewarm your home quicker so there’s less wait time for comfort.

The No Heat Checklist walks you through areas to check and steps to take before you call for heating repair. The first few steps are general for all types of heating equipment, then we get into tasks for specific types of heating systems.

1. Thermostat

Sometimes thermostat settings get bumped or mistakenly changed, which makes the heating system fail to turn on when you expect it to. Whenever you have no heat, your first stop for troubleshooting needs to be at your home’s thermostat.

  • Is the thermostat on? If not, power is the likely issue here. If your thermostat’s batteries are dead, it doesn’t communicate with your furnace or heating system, therefore you have no heat. Replace the batteries. If hardwired, check the breaker and reset if needed. If your thermostat still does not come on, you need heating repair – call us now.

  • If your thermostat is on, check its settings. Is “Heat” mode selected, or has someone accidentally knocked it into “Cool” mode? If you have cold air blowing from your vents but no heat, the thermostat’s fan setting may have been changed to “On” instead of “Auto”, which allows the blower fan to continuously run.

  • For programmable thermostats, verify your temperature schedules and make sure “Hold” or “Vacation” mode is not activated.

  • Next, look at the temperature settings. Set the thermostat a few degrees higher than the room’s temperature – this should start a heating cycle. If this does not start a heating cycle, there could be other issues still standing in the way of warmth – move on through the No Heat Checklist to address other potential areas of concern.

2. Access Panels

Some furnaces and air handlers have safety features which prevent the equipment from operating if an access panel is not secure. An access panel may have been knocked off, come loose, or have been damaged in some way. Inspect your interior heating equipment to verify that all panels are secure as they should be.

3. Power Supply

If your HVAC system equipment doesn’t have power, you get no heat. It’s time to check the various power supplies and switches to ensure your heating system has the electricity it needs to heat your home.

  • Start at your electrical panel (even gas furnaces use some electricity in operation). Find the breaker or fuse that powers the circuits of your HVAC equipment. Make sure they are not tripped or blown. Reset or replace if needed.

  • Next, we need to look at the physical on/off switches to the equipment – each piece of equipment has one. For furnaces and air handlers, look on the equipment or on the nearby wall. For exterior heat pump units, look on the unit or along the line set where the refrigerant lines go into the home. The switch may be on the exterior wall of your house. Make sure these switches are set to “On”.

4. Air Filter

Did you know that a clogged air filter has the potential to cut off heating? When the air filter is dirty, it restricts the flow of air through your system. When the heating equipment doesn’t receive enough airflow, it overheats, and the system shuts down for safety reasons. This is true for both furnaces and heat pumps that use an air handler.

  • Locate for Air Filter Compartment and Remove Any Access Doors
  • Pull Out the Old Filter
  • If It Is Dirty, Throw It Away and Use a New One
  • Reinsert the Filter According to the Markings on Its Frame (These Indicate Airflow Direction)
  • Make Sure the Filter Is Properly Inserted and Fits Snugly
  • Replace Access Doors, if Applicable

Give your heating system time to cool down, then see if it restarts and works well with the new filter. Additionally, closed vents throughout the home cause overheating, which leaves you with no heat when the system shuts down for safety. Walk through your home and make sure all vent louvers are open and all vents and grills are unblocked – remove any rugs, carpeting, furniture, and other items which are blocking them. If you still have no heat, check the following areas.

No Heat from Gas or Oil Furnaces and Boilers

Now let’s talk about troubleshooting the fuel supply for gas, oil, and liquid propane furnaces as well as boilers. Your furnace or boiler needs an adequate supply of fuel to burn and heat your home. If the fuel supply is interrupted, you are left with no heat.

  • For gas furnaces, check that the gas valve near the furnace is open. Verify there have been no interruptions to your utility gas service.

  • If your furnace is equipped with a pilot light, verify that it is lit. If it has gone out, you need to relight it. Follow the owner’s manual instructions. Turn off your gas valve for 10-15 minutes before you attempt to relight to avoid danger and stop gas from spilling into the area. Do not attempt to relight your pilot light if you still smell gas.

  • For oil and liquid propane furnaces, first verify at the tank that there is adequate fuel for heating. Next, check the valves to ensure they are open, which allows fuel to travel to the furnace.

 No Heat from a Heat Pump

A problem unique to heat pumps in the winter is freezing. Sometimes, the outside unit becomes covered with ice. This ice stops the heat pump from properly transferring heat, so you receive no heat indoors. This is an issue you want to solve quick before it causes damage to your system.

Normally, the heat pump runs a defrost cycle to remove minor frost buildup. It switches to cooling mode for a cycle that sends heat from the home to the outdoor unit to melt frost. When ice accumulation is too much, the defrost mode is unable to help. Additionally, malfunctions with the defrost may prevent the cycle from working.

If you find ice accumulation on your outdoor heat pump unit, follow these steps to troubleshoot:

  • Turn Off Power to the Unit

  • Use Water to Melt Away Ice

  • If possible, chip away ice buildup. Do not use sharp objects or blunt force as this causes additional damage to the unit.

  • Remove any debris that has built up surrounding the unit. Clear away snow drifts, yard debris, vegetation, and any outdoor items that you have stored in the two-foot area surrounding the unit.

  • Check above the heat pump and look at the gutters – it is common that a gutter issue causes water to spill down upon the heat pump and freeze. Clear gutter blockages and make repairs as needed.

If your heat pump does not thaw on its own or with your help, you need to call for heating repair. Our NATE-certified technicians thaw your heat pump and identify the source of its freezing. We repair system issues and even are able to recharge refrigerant levels in the winter so you don’t have to freeze indoors or rely on expensive backup heating.

No Heat from a Hot Water Boiler

If you use a hot water boiler to heat your home, issues specific to this type of heating system can cause no heat. Follow the above directions to check thermostat, power, and fuel supply issues. The problem may also be low water supply within the boiler.

If the boiler’s automatic water filling system doesn’t keep proper water pressure in the unit, it is unable to properly run. Some boilers allow for the manual feeding of water and have no pressure-reducing valve – open the water-feed valve to raise boiler pressure to the appropriate level (usually between 12 to 15 psi – check your owner’s manual for the proper pressure your boiler needs).

Ice can form on a boiler’s condensate pipe, which causes condensation to back up into the unit. When this happens, the boiler turns off, giving you no heat. The pipe needs to be cleared to restore function.

  • Locate ice accumulation at the end of the condensate pipe by the drain, as well as elbows or bends in the pipe.
  • Pour buckets of hot water as needed into the pipe to melt ice – do not use boiling water as the temperature could cause the pipe to crack.
  • If you don’t want to use hot water, you may use a heat blanket or hot water bottle wrapped around the pipe to thaw it.
  • Reset your boiler per the owner’s manual instructions.

No Heat Help from Williams Comfort Air

If you find yourself without heat after you work through our No Heat Checklist, it’s time to give us a call. Williams Comfort Air has NATE-certified technicians available day and night, 24/7 to perform the emergency heating repairs you need to stay warm and safe throughout the winter months. Call today to schedule heating repair for your furnace, heat pump, or boiler.

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