DETTSON Suprême Avantage SUP20-A120D12 Electric Furnace | 20 kW - 240V
The Dettson Suprême Avantage SUP20-A120D12: 20 kW of central electric heat, supplied at 120–240/208 V on three wires, with a 4-speed PSC motor.
Model numberSUP20-A120D12
514 316-2973 · sales@airgreen.ca
Quick facts
20 kW of electric heat for homes that need more
A three-wire version with a 1/3 HP PSC motor
The Dettson Suprême Avantage SUP20-A120D12 delivers 20 kW at 240 V, with a 10 kW first stage. It is supplied at 120–240/208 V on three wires and uses a 1/3 HP direct-drive PSC motor with 4 speeds. For heating, Dettson sets this motor at the factory to its high speed: 1,150 CFM at 0.5 in w.c. The published temperature rise is 60 to 80 °F at 240 V.
Like the whole Avantage series, it switches its elements on in sequence, makes them replaceable one by one and groups the continuous-fan switch, the low/high power switch, the heat-demand indicator light and the breakers on the front panel.
240 V or 208 V: a difference worth knowing
The output of an electric furnace with elements depends on the voltage it receives. Dettson publishes 20 kW at 240 V, but 15 kW at 208 V, or 51,256 BTU/h. In a single-family house in Laval or on the North Shore, the supply is generally 240 V; in some Montreal buildings, it is 208 V. We check the actual voltage before confirming that this size meets your needs.
Preparing the electrical circuit
At 20 kW, the electrical connection deserves attention. Dettson calls for a 125 A maximum breaker at 240 V (100 A at 208 V) and publishes a 108.05 A ampacity at 240 V. Your electrical service must be able to take this circuit on top of the rest of the house. During the visit, we assess your panel and state it clearly in the quote.
Looking ahead, the furnace accepts an air-conditioning or heat-pump coil of up to 3 tons, on the supply or return side. With a heat pump, the elements act as backup, never heating at the same time as the heat pump; the K03081 interface handles this Dettson rule.
A well-managed AirGreen installation
A family business established in Montreal for more than fifteen years, AirGreen holds RBQ licence 5645-9605-01 for ventilation, refrigeration and electrical work. For this model, we take care of:
- the free estimate, with the load calculation and the panel assessment;
- the written quote;
- multi-position installation, upflow, downflow with the DFB-SUP base depending on the floor, horizontal or suspended;
- the three-wire electrical connection, the duct connections and commissioning.
Dettson covers parts for 5 years in residential use. We work in Montreal, Laval, Longueuil, on the North Shore and on the South Shore.
Your quote, with no obligation
Ask for a free estimate: we check your voltage, your panel and your ducts, then give you a written quote. Take advantage of our financing if needed.
A 20 kW electric furnace for larger heating needs
The SUP20-A120D12 combines 20 kW of electric elements with a 1/3 HP PSC motor factory-set to its high speed for heating. It is wired at 120–240/208 V on three wires and accepts a coil of up to 3 tons.
- Ducted homes whose heat-loss calculation calls for 20 kW
- Replacing an old furnace on a three-wire single-phase supply
- Buildings supplied at 208 V, where the furnace delivers 15 kW
- Adding central air conditioning or a heat pump of up to 3 tons
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.
- Large dedicated circuit: 125 A maximum breaker at 240 V (100 A at 208 V) and 108.05 A ampacity at 240 V according to Dettson. Your electrical service capacity must be checked.
- 120–240/208 V single-phase 3-wire supply.
- With a heat pump, the elements and the heat pump must never heat at the same time (overheating risk according to Dettson): a thermostat or the K03081 interface must prevent it.
- The air-conditioning or heat-pump coil is not included; it goes on the supply or return side.
- In downflow, the DFB-SUP base may be required depending on the type of floor.
Manufacturer documents
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Frequently asked questions
Is my electrical service big enough?
That is the first check. Dettson calls for a 125 A maximum breaker at 240 V (100 A at 208 V) and publishes a 108.05 A ampacity at 240 V. We assess your panel during the free estimate and state in the quote whether it is suitable.
Why 20 kW at 240 V but 15 kW at 208 V?
Element output depends on the voltage. Dettson publishes 20 kW at 240 V and 15 kW at 208 V, or 51,256 BTU/h. In a building supplied at 208 V, the second value is the one that counts.
What power supply is needed?
A 120–240/208 V single-phase 3-wire supply, 60 Hz. We check your installation before confirming this model.
Can I add air conditioning or a heat pump?
Yes, with a coil of up to 3 tons on the supply or return side. With a heat pump, Dettson does not allow the elements and the heat pump to heat at the same time: the thermostat or the K03081 interface prevents it.
What is Dettson’s warranty?
Parts for 5 years in residential use and 1 year in commercial use. Labour is not covered by the manufacturer warranty.
A 20 kW Dettson 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.