A price list tells you what a part costs. It does not tell you which part is failing. The HVAC Price Increase List for November 2026 from ACHR News reports manufacturer increases "ranging as high as 15%" on select products. That is a reason to measure before you order, not a reason to skip the repair. A few minutes with a clamp meter can separate a capacitor from a motor, and a tired blower from a bad control board.
Why the Blower Is the Test
A furnace or air handler blower that hums, starts slowly, or stops on a call for fan can have several causes. The start capacitor or run capacitor may be weak. The motor winding may be failing. A bearing may be dragging, the squirrel cage may be coated with dust, or the static pressure may be high because of a clogged filter or closed registers. Each of these has a different part number and a different price. If you order a motor when the capacitor was the problem, you have spent money on the wrong item.
Tools and Safety First
You need a clamp meter that reads AC amps, a multimeter that reads volts and microfarads if it has that function, and the motor nameplate. Shut off power at the furnace switch and the service disconnect before you open the cabinet. Capacitors can hold a charge after power is off, so treat them as live until you have discharged them correctly or had a technician do it. Keep hands and tools clear of the blower wheel. If you are not comfortable working inside a live furnace cabinet, stop at the visual checks and call a licensed technician.
Run the Amp Check
Restore power, set the thermostat to fan only, and clamp the meter around one motor lead. Read the amp draw while the blower runs at its normal speed. Compare that number to the full load amps (FLA) on the motor nameplate. A reading well above nameplate usually points to a bearing, a dirty wheel, or restricted airflow. A reading near zero, or a motor that hums without turning, often points to a failed capacitor or a start problem. Check the capacitor label for its microfarad and voltage rating, and look at the top for bulging or oil residue. A capacitor with those signs is suspect even if the meter gives a marginal reading.
Check Voltage at the Motor
Low voltage at the motor makes a healthy motor draw more current and run hot. Measure voltage at the motor terminals or the control board supply with the blower running. Write down the number. A weak supply can come from a loose connection, an undersized circuit, or a control problem upstream, and none of those are fixed by swapping the motor.
Log the Readings Before You Order
Write the furnace or air handler model, the motor model, the nameplate FLA, the measured amps, the measured voltage, the capacitor rating, and the date. Attach a photo of each nameplate and the capacitor label. When a supplier quotes a higher price, the log shows whether the part on the quote matches the failure you measured. It also gives the next technician something specific to start from, which saves time you may be paying for by the hour.
When You Are Not on Site
Many people maintain a furnace for a parent who lives across town. The meter work still has to happen in the house, and someone has to be there to let the technician in, read the thermostat, and note what the blower sounds like on a cold morning. If you need a dependable person to be present for those visits, you can contact a locally owned St. Louis home care agency to ask about scheduled in-home help. Whoever goes into the home should bring the log, the nameplate photos, and the date of the last filter change, so the next person does not start from zero.