Why does the blower run after the furnace cycles off?

Why does the blower run after the furnace cycles off?

If your blower is constantly turning on/off when the furnace isn’t heating… …you most likely have a bad fan limit switch. The system uses a “temperature probe” to detect temperature changes inside the heat exchanger (see image below) and turns your blower on and off in response.

Why does my furnace blower only turn on once?

So at some warm air furnace systems the blower might turn on once, even twice after the call for heat has been satisfied. Typically, because the oil or gas burner is NOT running (because the thermostat is not calling for heat), the blower fan should not run more than a minute or two before stopping.

When to restart a purging cycle in a furnace?

If the timing cycle or purge airflow gets interfered with during purge testing, you must restart and conduct a new full purge. Purging airflow as outlined in the NFPA86 is a best practice for the operation and maintenance of a furnace.

How long does it take for Furnace Fan to stop blowing?

This shuts the furnace down and prevents your thermostat from calling for more heat. If the furnace was in the middle of a heating cycle, wait 3 to 4 minutes for the blower fan to stop running. Did your furnace fan stop blowing?

How does the purge of airflow work in a furnace?

The purge of airflow removes gaseous combustibles in a furnace and replaces it with air. As mentioned in our previous post about the NFPA86, any residue can lead to a fire or explosion, so this is an important process. Each part of a furnace, from the burner up to the stack, must be purged. The stack, however, does not have to be purged.

Why is my furnace blower coming on so early in the day?

Alright, I installed a new furnace a few months ago and have begun to notice an issue with the blowers. When the furnace first starts up, the exhaust blower should turn on to expel gas, then the flames are lit, then the main blower turns on.

If the timing cycle or purge airflow gets interfered with during purge testing, you must restart and conduct a new full purge. Purging airflow as outlined in the NFPA86 is a best practice for the operation and maintenance of a furnace.

This shuts the furnace down and prevents your thermostat from calling for more heat. If the furnace was in the middle of a heating cycle, wait 3 to 4 minutes for the blower fan to stop running. Did your furnace fan stop blowing?

The purge of airflow removes gaseous combustibles in a furnace and replaces it with air. As mentioned in our previous post about the NFPA86, any residue can lead to a fire or explosion, so this is an important process. Each part of a furnace, from the burner up to the stack, must be purged. The stack, however, does not have to be purged.