Hvac Fan Relay Troubleshooting

When troubleshooting efforts point towards a compromised relay a simple replacement job quickly brings your systems back online.

Hvac fan relay troubleshooting.

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. Purpose of the fan center relay. When the correct parameters are met a temperature switch or the computer will activate the relay which will allow power to the fans. A bad relay fan sequencer relay fan limit control or circuit board with contacts sticking this depends on the type and age of the furnace a problem with the limit switch or a problem that is causing the limit switch to open.

The first thing to do is check the relay or voltage from the board. One of the most common problems with furnace fans is a bad blower relay. Blower motor relays and delay on break timers at amperite. How to troubleshoot home furnace blower problems.

The cooling fan relay is the relay that controls the engine s cooling fans. A number of events can lead to this. It s a frustrating experience to turn on your furnace only to discover no heat comes through the vents. Relays are what open and close the electrical circuit in an air conditioner.

When a relay becomes stuck the circuit remains closed. If no voltage is recorded you will have to replace the board or the relay. This video will show you how to properly diagnose your blower by using the multime. As a result electric power to the fan motor doesn t stop and the fan continues to run.

Steps you can take to identify a problem with the ac fan. This is another common reason behind faulty. If the ac fan motor is bad or the capacitor is faulty you. The blower motor relay is a small but vital component in all hvac systems.

Ac contactors can wear out and are at the top of the list of common air conditioning service failures. 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.