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Quick answer: If your heat goes out, check three things first: the thermostat (set to Heat, set above room temperature, fresh batteries), the power to your furnace (the switch near the unit and the breaker), and the air filter. If the system still will not run, or you smell gas or something burning, turn it off and call an HVAC technician. In Lake Stevens and Snohomish County, Altitude Heating & Cooling answers after-hours calls at 425-201-1998.
Losing heat on a cold, wet night is stressful. The good news is that a lot of no-heat calls turn out to be simple problems you can check in about ten minutes. Here is the order we recommend.
Step 1: Check the thermostat
- Make sure it is set to Heat, not Cool, Off or Fan.
- Raise the setting 3 to 5 degrees above the current room temperature.
- If the screen is blank or dim, replace the batteries.
- Smart thermostats can lose Wi-Fi or run a schedule you forgot about. Check the app.
Step 2: Check the power
Most furnaces have a power switch on or near the unit. It looks like a regular light switch and is easy to bump off by mistake. Make sure it is on. Then check your electrical panel for a tripped breaker labeled furnace, heat pump or air handler. Reset it once. If it trips again, stop there and call for service. A breaker that keeps tripping points to an electrical problem that needs a technician.
Step 3: Check the air filter
A clogged filter chokes airflow. When that happens, the furnace can overheat and a safety switch shuts it down. If your filter looks gray or packed with dust, replace it and give the system a few minutes to reset.
Step 4: Check the furnace door and drain line
Furnaces have a safety switch behind the front panel. If the panel is loose or not fully closed, the furnace will not start. On high-efficiency furnaces, a clogged condensate drain can also shut the system off. If you see water pooling around the unit, that is a sign to call.
Step 5: Look for a blinking light
Many furnaces have a small window with a status light on the control board. The blink pattern is a code. The chart is usually printed inside the furnace door. Write the code down. It helps the technician diagnose the problem faster.
Stop and call right away if you notice any of these
- You smell gas. Leave the home first, then call your gas utility or 911 from outside.
- Your carbon monoxide alarm goes off. Get everyone out and call 911.
- A burning or electrical smell that does not fade after the first few minutes of a heating cycle.
- The breaker trips again after you reset it.
- The furnace turns on and off every few minutes and never warms the house. This is called short cycling, and it can point to a serious problem such as a cracked heat exchanger.
Heat pump owners: check for defrost mode
If you have a heat pump, it may blow cooler air for a few minutes while steam rises from the outdoor unit. That is defrost mode, and it is normal. If it lasts longer than about 15 minutes, or the outdoor unit is covered in a solid block of ice, it needs a repair. Our guide to heat pumps blowing cold air explains what to look for.
What happens when you call Altitude Heating & Cooling
If you have worked through these steps and the house is still cold, it is time for a professional. Altitude Heating & Cooling is a local HVAC company based in Lake Stevens. We answer after-hours calls, and we serve homes across Snohomish County, including Snohomish, Everett, Marysville, Granite Falls, Monroe, Lynnwood and Mukilteo.
Every visit starts with a full diagnosis. We test the system, find the real cause and explain what we found in plain language. You get clear options and the price before any work begins. If the fix is small, we fix it. If your system is near the end of its life, we tell you honestly and show you choices that fit your budget, with financing available.
Homeowners say it best. One recent review said they had been told by another company that they needed a whole new system, and our team repaired it instead. That is how we work.
No heat right now? Call 425-201-1998 or visit our emergency HVAC services page. Not urgent yet? Book our $49 HVAC diagnostic and maintenance visit and catch small problems before winter gets worse.
Frequently asked questions
Why is my furnace running but blowing cold air?
The most common causes are a thermostat set to Fan On, a dirty filter that tripped a safety switch, or an ignition problem. If changing the filter and thermostat setting does not fix it, call for a diagnosis.
Is no heat an emergency?
It is when temperatures drop near freezing, when someone in the home is very young, elderly or sick, or when pipes could freeze. In those cases, call right away.
Do you answer calls after hours?
Yes. Altitude Heating & Cooling answers after-hours calls for no-heat problems in Lake Stevens and Snohomish County.
How much does it cost to diagnose a furnace?
Altitude offers a $49 HVAC diagnostic and maintenance visit. You get the repair price before any work starts.
