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Central Heating Troubleshooting | How to Restore Heat

by vscontent on November 30, 2015

Everybody experiences a heating failure at one point or another. All heating systems convert fuel or energy into heat and distribute it throughout the building. When your heat goes out, there are several things you can check before having to call in the professionals.

furnace and heat pump troubleshooting

Although the best advice we can give you is to have professional heating and cooling maintenance check-ups every year, unfortunately breakdowns can still unexpectedly occur.

If you have no heat (or air conditioning), these central heating tips will help you get your HVAC system back up and running, but can also apply to many electric heating and water heating systems.

Central Heating Troubleshooting Tips

1.  Look at the thermostat. Does it have power? Is it set to “heat” in the winter and “cool” in the summer? For some tips on changing the batteries in your thermostat, watch this video:

Check to make sure your thermostat is out of direct sunlight and other sources of heat. This could give your HVAC system false temperature readings, leading to a variety of problems.

If you have an older, electromechanical thermostat, you may need to open up the housing and give the insides a good dusting.

For more advanced thermostat troubleshooting tips, read this guide by

2.  Check breaker box. You may be able to restore power and heat to your home by going to your breaker box and shutting off power to your thermostat and HVAC system. Wait for about 30 seconds before flipping the breaker back on. Hopefully, this little “reboot” is what you needed to get your heating system working again.

If you don’t know which breaker leads to which appliance or section of the home, now is a good time to find out and label all of your breakers for future use.

Before doing anything else, make sure power to your heating systems and thermostat is on and working. There may also be a shut-off switch near your indoor air handling unit. Check to make sure the switch by your furnace is turned on.

3.  Change air filters. Sometimes the cause of your central heating failure is a clogged or dirty air filter. Newer HVAC systems even have emergency shut off mechanisms in place to shut the system down if the air filter gets too dirty. This is because your central HVAC system needs proper airflow to work safely and efficiently.

If the blower turns on, but no heat is being distributed, you may have a clogged air filter. Before you call a professional, make sure you have a clean air filter in place. It’s located near the indoor air handler, where your air duct system enters the furnace. Take note of the arrow on the air filter and make sure it is pointing toward the furnace.

Watch this video to learn where your furnace filter is located and how to properly replace it with a clean one:

4.  Check the gas valve and flame color. Make sure your heating systems is getting the fuel it needs by checking to see if the gas is on or off. The gas may have been accidentally turned off at some point. Look for the shutoff valve on the gas line that feeds your furnace. The “off” position is normally perpendicular to the gas line, while the “on” positions is usually parallel.

If your gas line is active, check your pilot light. If your flame is yellow, orange, or any other color than BLUE, you should call your HVAC technician to conduct a heating inspection. In order to heat the fuel efficiently, your air to gas ratio must be exactly right. the flame should have an inner blue-green flame with a small orange tip. If there is not enough air, your flame will have a yellow tip and a mostly orange base. Too much air, and your flame will be too blue, with a dark blue inner flame.

5.  Make sure the exhaust flue is clear. It’s a good idea to periodically inspect your exhaust flue for leaks and blockages. Sometimes birds and other critters will find their way into your exhaust pipes, so it’s a good idea to turn your system off, dismantle your exhaust ductwork, and inspect for blockages.

Small leaks in your exhaust venting can be fixed with mastic sealant or aluminum foil tape. If you notice moisture and condensation near your exhaust, you could have a ventilation problem and carbon monoxide leaking into your home. Call your local HVAC technician to inspect your home for proper ventilation levels this winter and make sure you have working carbon monoxide detectors installed throughout the home (at least one on each level of the home).

6.  Flush out drain lines. A clogged drain pipe can cause a lot of problems for both furnaces and air conditioners. If they get too clogged, they’ll shut down automatically until they are cleared again. If you have a pool of water underneath your furnace, that’s a clear sign you have a clogged drain pipe. A water-stained ceiling underneath your system is also a common sign of drain pipe problems. The biggest problem of course is water damage to your floors and ceilings. Click here to learn why there is water leaking from your A/C or furnace.

To clean your drain line, follow these steps. It is also a good idea to maintain your drain line by periodically removing the drain hose from the inside and pouring a mixture of water and bleach down the line (25% bleach). After allowing it to soak, flush it and then reattach the drain hose.

Another prevention tip is to make sure you have clean air filters. If your filter is too clogged, dirt will find its way into the evaporator coils and then into your drain pipe. Also, you may need to clean out the drain pan located underneath your evaporator coils.

7.  Check your ductwork. If your heating system is working, but you can’t seem to get the heat you need, conduct and inspection of your duct system, including your vents and registers. Walk around your home and make sure that no vents or registers are closed or being blocked by rugs, heavy drapes, and/or furniture. All of your vents should be fully open to allow for proper air distribution. Click here for a more thorough explanation on why it’s NOT a good idea to close or block vents and registers in the home.

Warm air may also be escaping through leaks and cracks in your ductwork. Check for areas where there might be air leaks by holding up an incense stick or piece of toilet paper near suspected leak areas.

8.  Clean debris around indoor and outdoor HVAC units. Go outside and inspect your outdoor unit and intake and exhaust ducts. If there is anything blocking either of your ventilation ducts, you will need to unblock it. If ice is clogging your pipes, call in a professional.

If you have an outdoor heat pump, make sure there is nothing on top of the unit and that there is a minimum 24-inch clearance around the unit. You can clean the unit of dirt and debris with a simple garden hose. For a more thorough heat pump and condenser coil cleaning, call an HVAC professional.

Ensuring Proper Ventilation

Your fireplace, gas, and oil heating systems need proper ventilation for combustion gases. The best way to ensure proper ventilation of harmful gases, such as carbon monoxide, is to schedule annual professional maintenance for your heating system. You can improve indoor air quality, lower heating costs, and improve safety by making sure your chimney and ventilation systems are venting properly.

Sign up for Pacific Air System’s HVAC Maintenance Plan to reduce the risk of heating problems and breakdowns. We work on all HVAC makes and models, heat pumps, hybrid heating systems, forced air furnace, gas-fired furnace, electric systems, and much more!

If you are thinking about replacing your current HVAC system, give Pacific Air Systems a call for a free estimate!

Heating System Maintenance Tips

heating troubleshooting maintenance tips




For more information on how your heating and cooling system works and how to save money and energy this winter season, read these articles:

Call Pacific Air Systems Heating & Cooling at 253.292.3995 for 24/7 service!

For over 30 years, Pacific Air Systems has been proudly serving communities in Federal Way, Graham, Spanaway, University Place, Steilacoom, Sumner, Lakewood, Puyallup, Tacoma and Gig Harbor.

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