Common Furnace Problems in the Salt Lake Valley
Local furnaces work hard combating cold, dry air and are often affected by mineral deposits from our hard water. A frequent issue is a dirty flame sensor, where buildup from dust and dry air prevents the furnace from starting. Ignition problems, often due to a faulty hot surface ignitor or intermittent pilot, are also common.
High-altitude operation can affect gas pressure and combustion efficiency. Draft issues, exacerbated by wind in valleys like Herriman or Draper, can cause safety switches to trip. In older homes in Murray or Millcreek, aging ductwork can lead to uneven heating and strain on the system.
What an HVAC Technician Will Do
The HVAC technician we connect you with will start by asking about the symptoms. They will then perform a systematic diagnosis, checking thermostat signals, electrical power, the gas valve, and safety switches. They will inspect the heat exchanger for cracks, a critical safety check, and measure gas pressure and airflow.
For a dirty flame sensor, they will clean it with emery cloth. A failed ignitor or pressure switch will be replaced. They will also check the condensate drain line in high-efficiency units, which can freeze or clog. Repairs typically take one to three hours, depending on the part and accessibility.
What You Can Check Safely Before Calling
- Verify the thermostat is set to 'Heat' and the temperature is set above the current room temperature.
- Check the furnace's power switch, often located on the unit or a nearby wall, to ensure it is on.
- Inspect your home's main electrical panel for a tripped circuit breaker labeled for the furnace or HVAC.
- Ensure the furnace's access door or panel is completely closed, as a safety switch may prevent operation.
- Look at the air filter. A severely clogged filter can cause the furnace to overheat and shut down.
- For a high-efficiency furnace, check the PVC vent pipe outside for ice or snow blockages.
- Make sure all supply and return air vents inside your home are open and unobstructed.
When Furnace Repair Cannot Wait
Some situations require immediate professional attention. If you smell natural gas (a rotten egg odor), leave the home and call for help from outside. A cracked heat exchanger can leak carbon monoxide, indicated by sooty stains around the furnace or moisture on interior windows. If the blower runs constantly without heat, it could indicate a failing limit switch, which is a fire hazard.
Ignoring these signs risks safety. During a service call, the technician will use a combustion analyzer and carbon monoxide detector to ensure your system is operating safely.
Questions homeowners ask
How much does furnace repair typically cost in Salt Lake City?
Repair costs vary by the issue and part. Typically, a service call with a minor repair like cleaning a sensor or replacing a thermostat may range from $150 to $350. More involved repairs, like replacing a blower motor or gas valve, often range from $400 to $800. Prices depend on the specific furnace model and part availability.
Why does my furnace short cycle (turn on and off frequently)?
In our dry climate, a very dirty air filter is a common culprit, causing the furnace to overheat and shut off prematurely. It can also be a sign of an oversized furnace for the home or a failing flame sensor. A local technician can check airflow, sensor cleanliness, and the heat exchanger to diagnose the specific cause common in our older, drafty homes.
Is it worth repairing an older furnace?
This depends on the repair cost and furnace age. Many homes in Salt Lake City have furnaces 15-20 years old. A repair costing more than half the price of a new, high-efficiency unit may not be economical. A technician can assess its efficiency and reliability, considering our cold winters where a breakdown is more than an inconvenience.
What maintenance helps prevent winter breakdowns?
The most important thing is changing your air filter monthly during heating season due to our dusty environment. Have a professional inspection and cleaning performed annually, preferably in the fall. They will check gas pressure, clean the burner assembly and flame sensor, and ensure the venting is clear, which is vital for safe operation at our altitude.
My furnace is running but blowing cold air. What's wrong?
This often points to an ignition problem. The pilot light or hot surface ignitor may have failed, which is a common repair. It could also be a problem with the gas valve or a tripped limit switch from overheating. A technician will test these components to find the root cause.