Home » Steffes Serenity furnace with forced air heating with Electric Thermal Storage (ETS) | Installation in Montreal, Laval, Longueuil, South Shore and North Shore
Accumulateur de Chaleur avec Fournaise Électrique Serenity par Steffes | Installation à Montréal, Laval, Longueuil, Rive Sud et Rive Nord
Accumulateur de Chaleur avec Fournaise Électrique Serenity par Steffes | Composantes et spécifications techniques.
Accumulateur de Chaleur avec Fournaise Électrique Serenity par Steffes | Installation à Montréal, Laval, Longueuil, Rive Sud et Rive Nord
Accumulateur de Chaleur avec Fournaise Électrique Serenity par Steffes | Installation à Montréal, Laval, Longueuil, Rive Sud et Rive Nord
Accumulateur de Chaleur avec Fournaise Électrique Serenity par Steffes | Composantes et spécifications techniques.
Accumulateur de Chaleur avec Fournaise Électrique Serenity par Steffes | Installation à Montréal, Laval, Longueuil, Rive Sud et Rive Nord
Steffes

Steffes Serenity furnace with forced air heating with Electric Thermal Storage (ETS) | Installation in Montreal, Laval, Longueuil, South Shore and North Shore

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SKU: steffes-4210
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80 kWhof heat stored in 72 bricks
8 ha day with elements off during peaks
$22,000Hydro-Québec, with a heat pump ($15,000 alone)
Model accepted by Hydro-Québec100% electric 240 V · 16 kWWarranty: 5 years, parts
Talk to an expert · 514 316-2973
Model4210
SeriesSerenity
TypeCentral, forced air
Steffes spec sheet (PDF, Hydro-Québec) →
–Flex D winter season runs from December 1 to March 31.
Running costWhy this modelGrantSpecifications

The Steffes Serenity 4210 is a central forced-air electric thermal storage furnace. Its 16 kW of electric elements heat 72 high-density ceramic bricks (about 1,116 lb) while demand on the grid is low, then it releases that heat through your ductwork during Hydro-Québec’s winter peaks.

At a glance

  • 80 kWh (284,300 BTU) of stored heat.
  • 16 kW charging: 8 elements, 240 V.
  • ½ HP variable-speed blower and microprocessor control with digital display.
  • Compact footprint: 43 × 44 × 47 in (W × D × H), about 1,536 lb installed.
  • Limited 5-year parts warranty.

Why it pairs with Flex D

On rate Flex D, electricity costs 46.463¢/kWh during peak events (between 6 and 10 a.m. and between 4 and 8 p.m., 120 hours per winter at most) and from 4.886¢/kWh the rest of the time. The Serenity charges at the low price and carries you through events without paying the peak price.

Hydro-Québec grant

$15,000 for the storage unit alone, or $22,000 when installed with a new central heat pump of at least 24,000 BTU/h. Once per home, through a Steffes-authorized installer on Hydro-Québec’s list.
Steffes Serenity 4210 · Updated November 2, 2026

It buys its heat at 9¢ a kWh and heats the house when power costs 46¢.

A central furnace that fills 72 ceramic bricks with 80 kWh of heat outside peak hours, then shuts its elements off 8 hours a day. On Hydro-Québec’s Flex D rate, it turns peaks into savings.

Calculate the running cost Will it fit in my home?
80 kWhof stored heat
~650 °Cat the core of the bricks, according to Steffes
8 ha day of Flex D peak windows: 6–10 a.m., 4–8 p.m.
$22,000from Hydro-Québec with a central heat pump
01 · A day with the Serenity

It recharges while Québec sleeps, and heats with its bricks when everyone wakes up.

Its clock switches the elements off at peak times. Flex D events fall between 6 and 10 a.m. and between 4 and 8 p.m.: that is the day shown here. Tap an hour, or play the day.

Elements allowed: the bricks rechargeElements off: the bricks heatFlex D peak event

Bar height illustrates the heat held in the bricks. It is a diagram, not a measurement.

7 h
Elements off
Heat comes from–
Price per kWh on Flex D–
What is happening–

Rate Flex D, winter (December 1 to March 31), prices as of April 1, 2026 for the second tier, where heating falls.

02 · What it costs to run

A full charge of the bricks costs $7.28. The same heat, bought during a peak, would cost $37.17.

A storage furnace does not use less energy than an electric furnace: it buys it at the right time. Here is what that changes, with Hydro-Québec’s actual prices.

A full charge: 80 kWh

What the 80 kWh the bricks can store cost, depending on when you buy them.

Energy in a full charge80 kWh = 284,300 BTU
Difference with the peak price–

80 kWh × price per kWh as of April 1, 2026: Flex D winter outside events 9.103¢ (2nd tier); rate D 11.142¢ (2nd tier); Flex D during an event 46.463¢. Before taxes, excluding unit losses and the system access charge. For information only.

Your winter, three ways to heat

Enter your consumption from December 1 to March 31 (it is in your Hydro-Québec Customer Space).

4,00030,000 kWh
Heating during an event
Event hours this winter
–

Sample values, replace them with yours. Prices as of April 1, 2026: rate D 7.065¢ for the first 40 kWh a day, 11.142¢ above; Flex D in winter 4.886¢ and 9.103¢ outside events, 46.463¢ during. 121 days. With the storage furnace, 1.25 kW of other appliances remain during events. System access charge (46.154¢ a day) is the same and excluded. Hydro-Québec mentions $200 to $300 in savings a year, or more. For information only.

03 · What makes it unique

The most compact and lightest of the two storage furnaces Hydro-Québec accepts.

Hydro-Québec funds two Steffes models: the Serenity 4210 and the Comfort Plus 4120. Compared using the Steffes spec sheets it publishes.

04 · Serenity 4210 or Comfort Plus 4120

How many hours of heat are in the bricks, for your home?

Choose what your home needs in extreme cold. The bars show how long a full reserve lasts, against a 4-hour peak.

Heat demanded by the home

Theoretical calculation: full reserve ÷ heat demand, without losses. A peak lasts 4 hours at most. Real sizing starts from a heat-loss calculation of your home, done on site. Comfort Plus: maximum maintainable heat loss of 17.44 kW or 22.52 kW according to Steffes (calculated with the former 6–9 a.m. window).

Their footprint, to scale

Dimensions with the blower module (width × depth), Steffes spec sheets. Height: 47 in for the Serenity, 46 5/8 in for the Comfort Plus. Also allow for the plenums and service clearances.

05 · Inside the unit

Bricks at about 650 °C, and insulation that keeps it all inside.

Tap a number to see each component.

CONCRETE SLAB coil (optional) 1 2 3 4 5
06 · Hydro-Québec grant

$15,000 for the storage furnace, $22,000 with a central heat pump. Taken straight off the invoice.

The installation company files the claim on the LogisVert portal, not you. The grant applies after taxes. Enter your quote to see the bottom line.

Your project

No price is pre-filled: every home is different. GST 5%, QST 9.975%. The grant cannot exceed 100% of the pre-tax cost, and no tax applies to its amount. LogisVert installer guide v1.6, September 15, 2026. For information only.

Am I eligible?

Eight conditions for $15,000, one more for $22,000.

?Answer the questions to see your amount.
!
AirGreen’s Steffes authorization: in progress. For the grant to come off the invoice, the storage furnace must be installed by a Steffes-authorized company. AirGreen is not yet on Hydro-Québec’s list (October 2026). We tell you where our authorization stands at the assessment, before anything is signed.
07 · Will it fit in my home?

A concrete slab, ductwork, a bit of space and the right circuits. Check what you have.

The slab

1,536 lb

Installed weight, including 1,116 lb of bricks. Hence the need for an easy-access basement with a concrete floor.

The space

43 × 44 × 47 in

Width × depth × height, with the blower module. Nothing may be placed on top.

Electrical

91.5 A
Voltage240 V
Circuits2 × 60 A + 1 × 15 A
Blowers7 A max.

Ductwork

18.6 × 18.1 in
Supply outlet18.6 × 18.1 in
Return air16 × 16 in
Plenumssupplied at installation
0/5Check what applies
08 · Pitfalls

Six ways to lose the grant, or the savings.

09 · Your questions

What people ask us before signing.

10 · Full specifications

Every figure, with its source.

STEFFES Steffes spec sheet published by Hydro-Québec   HQ Hydro-Québec   AIRGREEN product listing

BrandAIRGREENSteffes
ModelSTEFFES4210
SeriesSTEFFESSerenity
TypeSTEFFESElectric thermal storage furnace, forced air
Charging powerSTEFFES16 kW
Heating elementsSTEFFES8
Heat storageSTEFFES80 kWh · 284,300 BTU
High-density bricksSTEFFES72 · about 1,116 lb
Installed weightSTEFFESabout 1,536 lb
Blower moduleSTEFFESabout 95 lb
Dimensions (W × D × H)STEFFES43 × 44 × 47 in
VoltageSTEFFES240 V
Minimum circuit ampacitySTEFFES91.5 A
Required circuitsSTEFFES2 × 60 A + 1 × 15 A
Maximum blower loadSTEFFES7 A
BlowerSTEFFES½ HP, variable speed
Supply / return airSTEFFES18.6 × 18.1 in / 16 × 16 in
ControlSTEFFESProgrammable control, digital display
WarrantySTEFFES5 years, parts (limited warranty)
Flex D event windowsHQ6–10 a.m., 4–8 p.m.
GrantHQ$15,000 alone · $22,000 with heat pump
Free assessment

We check the slab, the ducts and the panel before talking price. And we tell you the truth about the grant.

The heat pump half of the pair is our trade: sizing, installation, commissioning.

Book my free assessment

Or call: 514 316-2973

RBQ licence 5645-9605-01Subclasses 15.8 Ventilation, 15.10 Refrigeration and 16 Electrical.
Quote within 24 hoursThe detailed quote leaves our office within 24 hours of the visit.
Steffes authorization: in progressRequired for the grant to come off the invoice. We tell you where it stands before anything is signed.
Beware of calls “from Hydro-Québec”Hydro-Québec does no phone or door-to-door solicitation for LogisVert.
Sources checked November 2, 2026. Steffes spec sheets for the Serenity 4210 and Comfort Plus 4120, published by Hydro-Québec. Hydro-Québec: Central heating with a heat storage unit (financial assistance, FAQ, testimonials); list of Steffes-authorized companies (October 2026); LogisVert program, installer guide v1.6 (September 15, 2026); Electricity rates in effect April 1, 2026 (rate D, Flex D). Steffes, electric thermal storage furnace page (brick temperature, safety, warranty). Cost and invoice calculations are for information only (GST 5%, QST 9.975%); only Hydro-Québec confirms the assistance granted. Hydro-Québec may change or end the program at any time.