lennox pulse furnace

[pacnw]

I cannot explain why either, but I work for a Lennox dealer and they will NOT put in anything but OEM in the Pulse because it does not last.

I have been back on some that other companies have installed aftermarket motors in a sort time prior. The HO thinks the tech did not do something correct and that is why the new motor died so soon.

We just say it is wired correctly, as long as it is, and order the OEM motor and cap. Usually never have an issue unless it is a bad motor out of the box.

[chuckcrj]

Ahh, the good old Lennox 27F01 motor, or whatever the number is these days.
Don't repeat the frustration of thousands of technicians before you, just buy the OEM motor.



The motor in Lennox 4/5 ton drive furnaces is a 3/4 hp, 1075 rpm motor.
I'd bet you several $100 bills that any of your normal supply house 3/4 hp 1075 rpm motors, or rescue type motors, will overheat and fail in place of the motor Lennox uses.

I've even had a real motor supply/repair shop try to match one up for me and fail.
I've seen mention that either AO Smith or Fasco makes a motor that will replace the OEM motor, but I've never found one for sale in a supply house.

What is different about it?

[DOGBOY]

What is different about it?

you do realize we are service techs and not engineers? Right? some of us know what works and what doesn't.

dogboy

[hvac5646]

you do realize we are service techs and not engineers? Right? some of us know what works and what doesn't.

dogboy

I am sure we don't have to be engineers just because we want to know why an OEM part can not be crossed to to a competitive brand.

A motor is windings bearing a stator and a housing.
I have yet to find an OEM motor I cant cross.

I don't think an HO would appreciate a shoulder shrug in place of a reason why an OEM costs more than a generic part.

[mark beiser]

What is different about it?

The OEM motor has a thicker winding stack, higher amperage rating, and weighs significantly more than any of the commonly available 3/4 hp blower motors.
A motor shop even had me try a 1hp motor, didn't work out.

Look at the blower wheel in Lennox 4/5 ton drive furnaces from the 80's and 90's, not just the Pulse, but the 80MGF, G24, etc., it is bigger than you typically find in other furnaces.
If you look at the blower performance charts for those units, you will see that they have a significantly more powerful blower than most.

I've no doubt that there are aftermarket motors that will work, it's just a question of if anyone actually stocks them, which I've never had any luck with, even when dealing directly with a motor shop.

[billg]

The OEM motor has a thicker winding stack, higher amperage rating, and weighs significantly more than any of the commonly available 3/4 hp blower motors.
A motor shop even had me try a 1hp motor, didn't work out.

Look at the blower wheel in Lennox 4/5 ton drive furnaces from the 80's and 90's, not just the Pulse, but the 80MGF, G24, etc., it is bigger than you typically find in other furnaces.
If you look at the blower performance charts for those units, you will see that they have a significantly more powerful blower than most.

I've no doubt that there are aftermarket motors that will work, it's just a question of if anyone actually stocks them, which I've never had any luck with, even when dealing directly with a motor shop.

Thanks for telling us what you found, I like always like to know the why

[chuckcrj]

The OEM motor has a thicker winding stack, higher amperage rating, and weighs significantly more than any of the commonly available 3/4 hp blower motors.
A motor shop even had me try a 1hp motor, didn't work out.

Look at the blower wheel in Lennox 4/5 ton drive furnaces from the 80's and 90's, not just the Pulse, but the 80MGF, G24, etc., it is bigger than you typically find in other furnaces.
If you look at the blower performance charts for those units, you will see that they have a significantly more powerful blower than most.

I've no doubt that there are aftermarket motors that will work, it's just a question of if anyone actually stocks them, which I've never had any luck with, even when dealing directly with a motor shop.

Interesting. I have replaced a lot of Lennox motors with non OEM with no problems, but don't remember how many of them were 3/4 HP. I would guess that only about 1% of the pulse furnaces I've worked on are the 100k with the 4/5 ton blower.

[mb20fan]

The old motor is a lot heavier than aftermarket one for sure

[slctech]

The Pulse's heat exchanger runs about twice as hot as any other furnace. Thus, a larger and beefier blower wheel to move more air to meet the temp rise. Most off the shelf after-market blower motors can not handle the blower wheels in those Pulses, as earlier stated.

[mb20fan]

This house is a mess bad electrically the furnace breaker has a bunch of lighting on it.Plus a few outlets the thing is only a 15amp.This furnace will use most of that by it self and all of it on start up.not to mention it`s a lot of knob and tube still

[JUSTADDSOMEMORE]

Just replaced one 2 days ago. Part # 28F01. Pricing is about right. Use OEM the first time or you will be buying it for them next week.

[davidj001]

its been a while, but the last time i changed one it wasn't all that bad. the way it was installed under the house sucked

Agree with changing the furnace, once you have to change out a spark plug youll be wishing you had