STELPRO SFECM SFECM2321 Electric Furnace | 22.5 kW - 240V
The Stelpro SFECM2321 electric furnace: 22.5 kW at 240 V and a 1/2 HP variable-speed ECM motor, ready to back up a central heat pump in deep cold.
Model numberSFECM2321
514 316-2973 · sales@airgreen.ca
Quick facts
22.5 kW and an ECM motor to back up the heat pump when winter bites
The SFECM2321 in a few words
The Stelpro SFECM2321 produces 22.5 kW at 240 V, the highest output of the SFECM models with the 1/2 HP motor. It keeps the SFE series’ modulating electronic board, with its individually framed elements, Eco mode and built-in temperature sensor, and adds a variable-speed ECM motor that Stelpro highlights for constant airflow and better efficiency. The 23 in the model number is a code: the published output is 22.5 kW.
When the heat pump slows down, the furnace takes over
A central heat pump loses capacity as the outdoor temperature drops. With the coil installed on the furnace’s return side, Stelpro’s Type B mode lets the SFECM2321 make up for that loss. With the coil downstream, Type A mode, set at the factory, keeps the elements off while the heat pump answers the call. In both cases, the board compensates during defrost.
Take a large two-storey home on the North Shore: the heat pump heats as long as it can keep up, and the furnace adds its heat when the cold deepens. The choice between the two modes depends mostly on where the coil can be installed in your ductwork: we decide it on site. In summer, the Y2 terminal allows two-stage cooling.
Settings and accessories
7-position potentiometers set the airflow for each mode: low or high continuous fan, W1 and W2 heating, Y1 cooling. The board also has terminals for a humidifier and an air cleaner. If the ductwork needs more air than the published range, which goes up to 1,450 CFM, Stelpro offers the SFECM23211HP, with a 1 HP ECM motor.
Electricity and installation
Stelpro publishes a total amperage of 96 A at 240 V and 84 A at 208 V, a voltage at which the output drops to 16.9 kW. AirGreen, a family business established in Montreal for more than fifteen years, holds RBQ licence 5645-9605-01 for ventilation, refrigeration and electrical work: we check your electrical service during the free estimate, then give you a written quote.
Our technicians install the furnace upflow, downflow (FSB2 adapter, sold separately) or horizontal, connect it to the ducts and to the coil where applicable, make the electrical connection according to the manual and the rating plate, configure Type A or Type B mode and set the airflow. The 20 x 20 x 1 in filter is not supplied.
A written quote for your project
In Montreal, Laval, Longueuil, on the North Shore or the South Shore, ask for your free estimate. We will also walk you through the financing options.
22.5 kW, on its own or backing up a heat pump
The SFECM2321 heats a large home on its own or supports a central heat pump. Its board modulates the elements, and its 1/2 HP ECM motor follows airflow values set separately for each mode.
- Large homes whose heat loss calculation comes to 22.5 kW
- Central heat pump installed on the return side, with furnace backup in cold weather (Type B)
- Two-stage cooling (Y2 terminal)
- Homes equipped with a humidifier or an air cleaner
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- Sold alone, an electric furnace is not a heat pump: it does not qualify for the LogisVert grant.
- Total amperage of 96 A at 240 V (84 A at 208 V): the electrical service is checked before choosing this size. Breaker and conductor sizes are confirmed from the manual and the rating plate.
- At 208 V, the published output drops to 16.9 kW.
- For higher airflow, Stelpro offers the same output with a 1 HP ECM motor (SFECM23211HP).
- Not included: 20 x 20 x 1 in filter, FSB2 adapter (downflow) and SCOND neutral terminal block.
- Filter frame for a standard 20 x 20 x 1 in air filter (filter not included)
Manufacturer documents
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Frequently asked questions
Why 22.5 kW if the model is called SFECM2321?
The 23 in the model number is a code. Stelpro publishes 22.5 kW at 240 V and 16.9 kW at 208 V: that is the output used for sizing.
How does the furnace help the heat pump in winter?
With the coil on the return side (Type B), the furnace makes up for the heat pump’s loss of capacity in cold weather. With the coil downstream (Type A, factory setting), the elements stay off during the heat pump’s call. In both cases, the board compensates during defrost.
SFECM2321 or SFECM23211HP?
Same output. The SFECM23211HP has a 1 HP ECM motor for duct systems that need more air. The SFECM2321 keeps the 1/2 HP motor, with cooling published up to 1,450 CFM.
What amperage should be planned for?
Stelpro publishes a total amperage of 96 A at 240 V and 84 A at 208 V. We check your electrical service during the estimate, then the breaker and conductors from the manual and the rating plate.
What warranty does Stelpro offer?
Stelpro warrants the furnace for 5 years from the date of purchase against defects in material or workmanship, for the original purchaser only. Disconnection, transport and installation are not covered by the manufacturer.
A 22.5 kW Stelpro SFECM furnace, installed by AirGreen
Tell us about your project: we check the sizing, confirm availability and send you a quote. Or let our technicians install it for you.
Specifications from the manufacturer’s documentation, checked on October 19, 2026.