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Furnace error code 3 flashes

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Furnace error code 3 flashes

Furnace error code 3 flashes can occur when a gas valve safety switch is set to the wrong position.

Before running a furnace diagnostic test, you must verify that the furnace is getting power. This can be done by checking if there are 24 volts between the center terminal and any of the other terminals on the power switch or transformer. If it doesn’t have any voltage, check for a blown fuse or tripped circuit breaker.

This error code 3 flashing might indicate problems with the gas valve or the ignition. Check your furnace filters and make sure that there are no obstructions.

Furnace error code 3 flashes indicate that the furnace is short cycling and shutting off before it reaches its desired temperature.

A short furnace cycle when it shuts off before the temperature inside the home has built up sufficiently.

This can happen if there is a problem with the heating system thermocouple or the air sensor.

The most common causes of this problem are:

1) The furnace thermostat is set at too low a temperature, such as 2 degrees, meaning that the thermostat cannot determine whether to turn on.

2) There are problems with the heating system thermocouple or air sensor connected to the furnace’s electronic control board.

3) The wiring in your heating system is defective and needs to be replaced.

“Inspections, Installations, Repairs & Maintenance”