A furnace that runs but blows cool air is one of the most common winter calls in Cache Valley. Before you pay for a visit, a few of the causes are things you can check yourself in ten minutes.
1. The thermostat
Make sure it is set to Heat and the fan is set to Auto, not On. With the fan on, the blower runs between heating cycles and pushes room-temperature air, which feels cold.
2. The filter
A clogged filter makes the furnace overheat and shut its burners off while the fan keeps running. Pull the filter. If you can’t see light through it, replace it.
3. The furnace switch and breaker
Look for a light-switch style power switch near the furnace and the breaker in your panel. Both get bumped more often than you’d think.
4. The gas valve
The handle on the gas line to the furnace should run in line with the pipe. If other gas appliances are also out, call your gas utility.
5. Vents and registers
Closed or blocked registers raise the temperature inside the furnace and trip its safety limit. Open them, including in rooms you don’t use.
6. The intake and exhaust pipes
High-efficiency furnaces vent through plastic pipes on an outside wall. Snow and ice can block them after a storm. Clear them gently by hand.
7. The error code
Most furnaces have a small window with a blinking light. Count the blinks and match them to the chart on the inside of the furnace door. Write the code down for the technician.
When to stop
If you smell gas, leave the house, then call 911 and your gas utility from outside. If the furnace starts and stops every few minutes, or you have reset it more than once, leave it off and have it looked at.
Need a hand? Logan Plumbing Co. connects Logan and Cache Valley homes with licensed local heating and cooling pros. Call (435) 294-3502 or request a free quote.