Heating, Air Conditioning, Fridge, HVAC/Furnace Blower


Hi, Jim.

I have a couple questions regarding my furnace blower and possible replacement of it.

I have a carrier 52mcb100-1 gas furnace. According to what I can find out it has a 1/2hp 4 speed 115v 1075rpm motor. It is a single stage furnace with a PSC motor.

I was looking at a couple things. I want to leave my blower motor on continuous to help balance the temperatures between the 1st and 2nd floor, however with the current motor it uses a bunch of electricity.

Looking on the net I found the evergreen motor. It is a ECM motor that claims it can replace older PSC motors, and save a good amount of electricity. Here is a link; http://www.genteqcomfort.com/EnergyEfficient/theMotorMatters.aspx

Also, the motor I was looking at to replace my current motor; http://www.comfortgurus.com/product_info.php/products_id/3645

Last question; I have been experimenting with leaving my furnace blower fan "ON" continuous instead of "AUTO" and the strange thing is, when ever the furnace calls for heat the fan shuts off for about 1 minute and furnace ramps up comes on with heat, then when the furnace no longer calls for heat the fan stays on. Is this normal?

Thank You and have a great day,

Hi Steve,

For your situation the ECM motor is the right choice. Sounds like you have done your homework. On some ECM's some modification might be needed. But it's no big deal. One thing to note, if you run a ECM on low speed it won't be as efficient as running on a higher speed.

As your having temperature problem's between 1st and 2 nd floor, I would check the balancing dampers on the duct work. Some systems have them, some don't.

Let me know if you have any other questions.

Heating, Air Conditioning, Fridge, HVAC

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Jim S.


I can answer questions on gas or electric furnaces, ac units and heat pumps. I don't work on boilers,chillers,or home appliances.


I have been in the HVAC trade for over 35 years. For the past 15 years I have owned my own business. I am semi-retired so I can answer questions in a timely manner.

I attended trade school for 5 years on weekends and evenings. This was very hard to do, but well worth it!

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