It’s the coldest time of the year and you have no heating. This is a scenario no one wants to face. If your furnace stops working, like most people you’re probably thinking the worst. But a lack of heat is not always a sign of a full-fledged furnace breakdown. Before you call an emergency HVAC company, start with these troubleshooting steps to see if you can isolate if not resolve the problem on your own
Check the thermostat display. If it’s not on as usual and your furnace isn’t running, the thermostat’s batteries may have drained or the device isn’t getting power. Change the batteries (if applicable) or go to the electric panel and check for a tripped circuit breaker. Resetting it should get your heater going again.
If the thermostat is on, verify it’s in heat mode. There will be no heating if the system is set to cool, so adjust as necessary. Check the fan settings as well. If the fan is set to “on” mode instead of “auto”, it will run even when the heater’s off and may blow cold air. Also, make sure the thermostat is set higher than the room temperature, which signals the furnace to start when the air is cooler; adjust accordingly to see if the heater cycles on.
Every furnace or air handler has a switch located on the unit or a nearby wall. The system will work only when the switch is in the “on” position. It’s easier than you think to accidentally hit an on/off switch. So, this is a good place to look if a heater isn’t running.
A clogged filter can cause a furnace to overheat, in which case it will shut down. Locate the filter and check it for dirt and dust. Change the filter if it’s dirty. This is also a common reason for no heating even when the blower is running. To avoid future issues, replace a flat filter once a month and thicker pleated filters every three months; or, more frequently if you have pets or kids.
If a vent is blocked or closed, this can also cause a furnace to overheat and shut off. Check the return air grills throughout your home to make sure furniture, curtains, rugs, and objects aren’t blocking them. Vent louvers must be open as well. If you find any closed ones, moved them to an open position and see if your furnace kicks in. Then check outside vents for leaves or debris and clear them to open the intake or exhaust.
Locate the gas valve to see whether it was turned off by accident. Turn the handle on the gas meter until it is parallel to open the line. If you have an older furnace, check the pilot light to see if it is on; if not, shut the gas for 10 to 15 minutes and follow the owner’s manual for relighting the flame. Call for help if you smell gas.
If you have an oil or liquid propane heater, check the fuel storage tank. You may have no heating because the unit’s fuel source has drained. Refilling the fuel tank should resolve the problem. Also, check the tank’s valves and open them if necessary; this will make sure fuel will flow to your heating equipment.
This step requires a little bit of work but can save you an emergency call. Turn off the furnace and then set the thermostat as low as it goes. Then remove the duct and check the flue for debris, birds, or other animals. A clogged flue can prevent the system from exhausting so it could stop working. Once the exhaust is clear, reassemble the parts in the order you removed them.
Furnaces can drain gallons of condensation per day. If the drain lines clog up with sediment or mold, a heater will stop working. To resolve the issue, remove the drain hose and clean it with a mix of bleach and water. Let it sit for a few minutes and then flush out the hose before reinstalling it.
Ice causes big problems for pipes. If you use a hot water boiler, see if the condensate pipe is frozen. Ice buildup tends to occur at the bends in the pipe. You can melt ice by pouring hot water (not boiling) down the pipe or wrapping the pipe in a heat blanket. Once the ice is gone, reset the boiler.
Heavy ice on a heat pump can block heat transfer and damage the system. While a heat pump has a defrost cycle, ice accumulation is a different story. It needs to be resolved by turning off the power and pouring warm water over the affected area. Gently chip at the ice if you can and clear any snow, vegetation, or outdoor items from the unit. Also, inspect the gutters for leaks that can cause water to drip on the unit and freeze (and clear or repair a gutter as needed).
If none of these steps have gotten your heater working again, it’s time to call a professional. NexGen employs qualified heating repair technicians who are prompt, trustworthy, and experienced at fixing any problem. Our trucks are fully stocked with parts and equipment so repairs can be completed quickly. We’re available 24/7 for emergencies. If you have no heating, and can’t figure out why, call NexGen at 833-729-9735.