Hvac Fan Relay Troubleshooting
When a relay becomes stuck the circuit remains closed.
Hvac fan relay troubleshooting. Purpose of the fan center relay. The cooling fan relay is the relay that controls the engine s cooling fans. It s a frustrating experience to turn on your furnace only to discover no heat comes through the vents. Steps you can take to identify a problem with the ac fan.
The purpose of the fan center relay is to provide a low voltage control 24 volts to control a relay that can be used to control two speed blower motors and auxiliary circuits in heating or cooling equipment many of the newer furnaces do not have fan center relays but many of the older furnaces and some new furnaces still do. Ac contactors can wear out and are at the top of the list of common air conditioning service failures. The relay will usually be activated once it is detected that the vehicle s temperature approaches excessively high temperatures. The blower motor is crucial to the proper functioning of your hvac system.
An ac contactor is a 25 mechanical relay that uses low voltage power from the thermostat to switch 220 volt high amperage current to the compressor and condenser fan. If the ac fan motor is bad or the capacitor is faulty you. The first thing to do is check the relay or voltage from the board. This video will show you how to properly diagnose your blower by using the multime.
One of the most common problems with furnace fans is a bad blower relay. As a result electric power to the fan motor doesn t stop and the fan continues to run. If there is a battery check if it is working properly. When the correct parameters are met a temperature switch or the computer will activate the relay which will allow power to the fans.
How to troubleshoot home furnace blower problems. When troubleshooting efforts point towards a compromised relay a simple replacement job quickly brings your systems back online. This is another common reason behind faulty. If no voltage is recorded you will have to replace the board or the relay.
The blower motor relay is a small but vital component in all hvac systems. Blower motor relays and delay on break timers at amperite.