Overview
TroubleShooting
Problem | Probable Cause |
---|---|
Won't Start |
|
Won't Start - Buzzing Sound at AC Unit |
|
Furnace fan not turning on |
|
Water running around the outside of the furnace |
|
Bypass the Thermostat
With the power on, you can bypass the thermostat by pushing the plunger in to connect the 240v.
Listen for buzzing, etc...
Next check for 240 VAC on contact points.
Capacitors
- Start Capacitor (black)
- Dual Run Capacitor(grey)
Checking the Capacitor
The capacitor has a rating on it. Capacity is written as HERMS capacity + FAN capacity.
ex. 35+4uF
Measure the capacity from common to what you are measuring.
ex. Fan measurement should show 4uF and Herms should show 35uF.
Thermostat Wiring
Voltage: 24 VAC
Mark's Unit
Sears Model# 875.47270
MD: 3207-1 11A
References
Reference | URL |
---|---|
How Air Conditioners Work | https://servicechampions.com/how-your-air-conditioner-works/ |
AC Won't Start | https://www.youtube.com/watch?v=wzAA4dlp_70 |
AC Capacitor Fail | |