Furnace fan running at the same speed in first/second stage heat

[helpWithStuff]

Hi,

I have a 2 stage furnace with a variable speed blower. It seems that when my furnace is in either first or second stage, the blower is running at the same speed, despite a manual that indicates that there should be different speeds for each stage of heat.

Wondering if I'm just misunderstanding how this should be working, or if it is something that should be addressed.

 

[Fitter30]

Brand, model and pic of the wiring diagram ( probably on inside blower door)?

 

[Sponsor]

 

[Breplum]

If it is an ECM then it probably needs to be replaced. Qualified repair person would have a ECM motor tester for specific brand… If the motor is simple multi—stage and gets the power from two different sources on the main board, then we check the power to each stage…presuming the burner is stepping appropriately

 

[WorthFlorida]

Hi,

I have a 2 stage furnace with a variable speed blower. It seems that when my furnace is in either first or second stage, the blower is running at the same speed, despite a manual that indicates that there should be different speeds for each stage of heat.

Wondering if I'm just misunderstanding how this should be working, or if it is something that should be addressed.

Is this a new problem? As Brplum asked, a model number and brand would be helpful. Depending on the model, there could be options for fan speeds as your manual states, however, the fan motor could have been changed in years pass.

What are your type of heat stages and thermostat.

 

[fatima mehru]

It's possible that there is a misconfiguration or malfunction in the furnace's control system. Check the thermostat settings to ensure it's properly configured for a two-stage system. Additionally, inspect the wiring and connections between the thermostat, furnace, and blower to rule out any issues there.

If everything appears to be set correctly, it might be a problem with the furnace's control board or blower motor, and professional inspection or consultation with the manufacturer may be necessary to address the issue and ensure the proper functioning of the variable speed blower in relation to the different stages of heat.