Steffes Serenity: up to 80 kWh of heat in reserve before the peak
A central electric furnace that heats 72 bricks while electricity is off-peak, then blows that heat into your ducts. Hydro-Québec names it in LogisVert: $15,000 to replace a central heating system, $22,000 with a central heat pump, by a Steffes-authorized company.
Charge, hold, deliver
The Serenity does not make its heat at the moment you need it: it prepares it in advance. Here are the three stages, as Steffes’ manual describes them.
Charge off-peak
Eight 2,000 W elements (16 kW) heat the core once the peak is over. An outdoor sensor adjusts how much heat to store according to the cold.
Hold it in the bricks
72 bricks hold up to 80 kWh, or 272,960 BTU, in a unit weighing about 1,569 lb once installed.
Deliver through your ducts
A variable-speed ECM blower (100 to 1,300 CFM) sends heated air into your ducts, including during the peak, when the elements are off.
Source: Steffes 4210 owner’s and installer’s manual, document 1201282 Rev 5 (sections 1 and 3, appendix A.01).
Pick an hour and a temperature
The tool applies two written rules: Hydro-Québec’s windows for the LogisVert grant, and the factory charge settings in Steffes’ manual.
Factory settings C001 and C002 from the manual; the installer may set them differently.
- For the LogisVert grant, Hydro-Québec requires that no heating element run from 6 to 10 a.m. or 4 to 8 p.m. (Eastern Standard Time), all year.
- The blower keeps sending air heated by the bricks into your ducts.
- After the peak, at -12 °C: at -12 °C and below, factory setting C002 targets a full charge, 80 kWh.
Steffes’ heat reserve, planned here.
Steffes designs the Serenity and publishes its installation rules. AirGreen checks at your home what those rules require: electrical, floor, ducts. Each does what it does best.
What Steffes brings
- Thermal storage since 1987Division formed in 1987 per Steffes; headquartered in Dickinson, North Dakota.
- The Serenity 421080 kWh in 72 bricks, 16 kW charging input, variable-speed ECM blower.
- The installation rulesManual 1201282 Rev 5: power supply, clearances, return-side coil.
- Manufacturer warranty5 years from purchase, at most 7 years from manufacture, parts only.
What AirGreen brings
- Sales and installationThe Serenity 4210 in our store, in Montréal, Laval, Longueuil, the South Shore and the North Shore.
- The written rules, appliedThe tools follow Steffes’ manual and Hydro-Québec’s guide, and say “to be checked” where they are silent.
- Free estimateElectrical service, floor and ducts looked at in your home before the final choice.
- RBQ 5645-9605-01Subclasses 15.8, 15.10 and 16.
The result: a Serenity planned around your home, price on quotation.
The Serenity 4210, by the manual
A heat storage furnace is planned around three things first: the electrical service, the floor and the ducts.
| Model | 4210 (4200 series, Serenity) |
|---|---|
| Storage | 80 kWh (272,960 BTU) |
| Charging input | 16.0 kW · 8 elements of 2,000 W |
| Core | 72 bricks |
| Power | 240 V, 60 Hz |
| Circuits | 1 circuit with 92 A minimum ampacity (continuous load included), or 2 charging circuits of 50 A |
| Blower | ECM 1/2 HP, variable speed, 100 to 1,300 CFM |
| Max. static pressure | 0.75 in water column |
| Coil (heat pump or A/C) | Return side, 1.5 to 3 tons, 20 × 20 in opening |
| Dimensions (W × D × H) | 43 × 44 × 47 in |
| Installed weight | About 1,569 lb, including 1,134 lb of bricks |
| Room air | Below 29 °C (85 °F) |
Source: Steffes 4210 manual, document 1201282 Rev 5, appendix A.01, sections 3.02 to 3.09. The 2024 brochures give other values (284,300 BTU, 91.5 A): the manual governs here.
$15,000 or $22,000? Four questions
The rules come from Hydro-Québec’s guide for installation companies (v1.6, September 15, 2026) and its LogisVert page, re-read on October 26, 2026.
Nominal capacities in BTU/h. Indicative only: Hydro-Québec decides.
- Steffes model 4120 or 4210 (Serenity).
- Elements off from 6 to 10 a.m. and 4 to 8 p.m. (Eastern Standard Time), all year.
- Company on Hydro-Québec’s list of Steffes-authorized companies.
- At most 100% of the cost before taxes; claim within 9 months of installation.
- No other grant added here. Hydro-Québec may change its program without notice.
5 years on parts, per Steffes
What Steffes and the programs themselves say, re-read in October 2026.
- Repair or replacement of defective parts
- 5 years from purchase, at most 7 years from manufacture
- Labour and return of parts paid by the customer
- Void if the unit is moved from where it was installed
- Excluded: unit altered, improperly installed, maintained or used
The program that names the Steffes models: $15,000 or $22,000, conditions in section 04.
No category for heat storage furnaces or electric furnaces (NRCan).
Program ended March 31, 2026 (Government of Québec).
Canada grant closed in Québec since September 30, 2025 (NRCan).
Frequently asked questions about the Serenity
What is a central heat storage furnace?
An electric furnace that heats a brick core when electricity is off-peak, then blows that heat into the ducts as needed. Steffes’ Serenity 4210 stores 80 kWh in 72 bricks, according to its manual.
Does the Serenity heat during peak hours?
Yes, with the heat already stored. For the LogisVert grant, Hydro-Québec requires the heating elements to stay off from 6 to 10 a.m. and from 4 to 8 p.m. (Eastern Standard Time), all year; the blower keeps delivering heat from the bricks.
Why “Eastern Standard Time”?
That is the time written in Hydro-Québec’s guide. From early November to mid-March it matches your clock. During daylight saving time, the same windows fall from 7 to 11 a.m. and from 5 to 9 p.m. on the clock.
What electrical supply does it need?
240 V. Steffes’ manual gives two options: a single circuit with a minimum ampacity of 92 A, or two 50 A charging circuits. Your electrical service capacity is checked on site.
How much room does it take?
43 × 44 × 47 in (width × depth × height) and about 1,569 lb once installed, including 1,134 lb of bricks. Clearances to combustibles: 3 in at the back, 1/2 in underneath, 12 in on top; for service, 36 in in front and 12 in on the side opposite the air handler.
Can a central heat pump or air conditioner be added?
Yes. The indoor coil goes on the return-air side (mandatory with a heat pump), 1.5 to 3 tons according to Steffes’ manual. For Hydro-Québec’s $22,000, the central heat pump must be at least 24,000 BTU/h.
Which Hydro-Québec grant applies?
LogisVert: $15,000 to replace a central heating system with a heat storage furnace, or $22,000 for a heat storage furnace with a central heat pump. Steffes models 4120 or 4210 (Serenity), once per dwelling, up to 100% of the cost before taxes, claim within 9 months. Hydro-Québec may change the program.
Who can install it for the grant?
A company registered with the Registraire des entreprises, holding the RBQ licences and on the list of Steffes-authorized companies published by Hydro-Québec. According to the guide, that list is not updated in real time. The grant is deducted from the company’s invoice.
How is charging controlled?
By an outdoor sensor: at the factory setting, charging starts at 10 °C (C001) and targets a full charge at -12 °C (C002). The peak can be signalled by power line carrier, a low-voltage wire, a time clock module or line voltage, according to the manual.
What is the warranty?
Steffes’ own: 5 years from purchase, no more than 7 years from manufacture, to repair or replace defective parts. Labour and returning parts are paid by the customer, and the warranty is void if the unit is moved.
Is the Serenity ENERGY STAR certified?
ENERGY STAR has no category for heat storage furnaces or electric furnaces. Hydro-Québec’s grant names the Steffes models directly.
What is the difference between the 4120 and the 4210?
They are two Steffes heat storage furnaces named by Hydro-Québec: the 4120 (Comfort Plus 4100 series) and the 4210 (Serenity 4200 series). We sell the Serenity 4210.
No question matches. Write to us or call 514-316-2973.
A heat storage furnace is planned on site
Electrical service, floor, ducts, heat pump or not: everything is checked at your home before the final choice. Free estimate across Greater Montréal. Price on quotation.
Sources checked in October 2026
- Steffes — owner’s and installer’s manual, model 4210 (FR), document 1201283 Rev 6, uploaded January 2025
- Steffes — Owner’s and Installer’s Manual, model 4210 (EN), document 1201282 Rev 5, uploaded January 2025
- Steffes — manuals and warranties, page modified Oct. 6, 2026, read Oct. 20, 2026
- Steffes — company history, read Oct. 20, 2026
- Hydro-Québec — LogisVert program, residential customers, re-read Oct. 26, 2026
- Hydro-Québec — LogisVert, participation guide for installation companies, v1.6, Sept. 15, 2026
- Hydro-Québec — list of Steffes-authorized companies, April 2026
- NRCan — ENERGY STAR certified products, page modified July 9, 2026
- Government of Québec — Chauffez vert, program ended March 31, 2026
- NRCan — Canada Greener Homes Grant, closed in Québec on Sept. 30, 2025
Steffes and Serenity are trademarks of Steffes, LLC. AirGreen sells and installs this unit; the warranty is the manufacturer’s. Grant amounts are Hydro-Québec’s, which may change its program.
The Steffes shop
The Serenity 4210, right below.
Open the Serenity product page. Price on quotation.
