THERMO 2000 AltSource 50 Thermal Mass Electric Boiler | 9 kW - 240V
The 9 kW AltSource 50 is a 48 US gal thermal mass electric boiler with two 4.5 kW elements, whose controller sets output according to the outdoor temperature.
Model numberALTSOURCE50-9
514 316-2973 · sales@airgreen.ca
Quick facts
A 9 kW electric boiler that sets its output by the weather, backing up your renewable system
The essentials of the AltSource 50-9
The AltSource 50-9 is a thermal mass electric boiler from Thermo 2000. Its tank holds 48 US gal of water, and its 9 kW output at 240 V, or 30,708 BTU/h, is split into two 4.5 kW elements over two stages. Thermo 2000 designs it as the backup source of a renewable-energy heating system, such as an air-to-water heat pump, geothermal or solar, and presents it as the only high water volume electric boiler on the market.
A controller that follows the weather
An October day does not call for the same heat as a January night. The T2 UltraSmart controller takes this into account: with the supplied outdoor sensor, it modulates output and water temperature according to the outdoor temperature. When it is mild enough, it shuts heating off. It also offers a Boost mode, a pump purge function and 24 V power for accessories.
Two operating modes are available: standalone electric, the default setting, or automatic transfer controlled by an external contact. We set the mode based on how your main source is connected to the loop.
Which home it suits
Think of a house in Longueuil or on the South Shore heated by hot-water baseboards, where an air-to-water heat pump now does most of the work. The AltSource 50-9 takes over as needed and replaces an old electric boiler at the same time. It fits in a tight space: 22 in in diameter, 25 1/2 in deep with the door and 56 7/16 in high, for a weight of 280 lb before filling.
On the electrical side, Thermo 2000 lists a 50 A breaker and Cu 8 / Al 6 wire gauge at 240 V single phase. If the building has a 208 V supply, output becomes 6.8 kW (32.6 A). The loop connects in 1 in NPT and operates at a maximum pressure of 30 psi; the manufacturer recommends a #30 expansion tank with baseboards or a radiant floor, and a #60 with cast-iron radiators.
What AirGreen’s installation covers
The on-site estimate is free. We examine the main source, the hot-water loop, the electrical panel and the planned location, then give you a written quote that specifies the boiler, circulator, expansion tank and electrical work. At installation, we set the unit in place, connect it, mount the outdoor sensor, fill and purge the system, then set the controller’s heating curve with you.
Thermo 2000 covers the tank for 15 years in residential use and the electrical and mechanical components for 2 years. AirGreen is a family business established in Montreal for more than fifteen years, holding RBQ licence 5645-9605-01 in ventilation, refrigeration and electrical work.
Get your quote
We install in Montreal, Laval, Longueuil, on the North Shore and on the South Shore. The estimate is free, the quote is in writing and financing is available.
An electric backup that follows the weather
The AltSource 50-9 complements an air-to-water heat pump, a geothermal system or solar collectors. Its T2 UltraSmart controller, linked to the supplied outdoor sensor, matches output and water temperature to the actual cold.
- House heated by hot-water baseboards and an air-to-water heat pump
- Backup for a geothermal system in a mid-size house
- Replacing an aging electric boiler with a thermal mass unit
- Projects where heating should shut off automatically in mild weather
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- 240 V single-phase circuit with a 50 A breaker and Cu 8 / Al 6 wire gauge, according to Thermo 2000.
- At 208 V, output drops to 6.8 kW (32.6 A).
- Thermo 2000’s documents do not mention Wi-Fi, a 0-10 V signal or a building management system connection.
- The circulator and expansion tank are not on the list of supplied parts; recommended tank #30 (baseboards or radiant floor) or #60 (cast-iron radiators).
- Height of 56 7/16 in, diameter of 22 in, depth of 25 1/2 in with the door, weight of 280 lb before filling.
- 30 psi (207 kPa) relief valve
- Drain valve
- Temperature and pressure gauge
- Automatic air vent
- Heating elements
- UltraSmart controller
- Outdoor sensor
Manufacturer documents
Explore the range
Electric boilersSee allSame brand
THERMO 2000See all
Frequently asked questions
What does warm weather shutdown do?
The T2 UltraSmart controller shuts heating off when the outdoor temperature, read by the supplied sensor, is mild enough. The rest of the time, it modulates output and water temperature according to the cold.
Can it be controlled over Wi-Fi?
Thermo 2000’s documents for the AltSource do not mention Wi-Fi, a 0-10 V signal or a building management system. The controller offers a 24 V output for accessories and two modes: standalone electric or automatic transfer.
What electrical circuit is needed?
A 50 A breaker and Cu 8 or Al 6 wire gauge, at 240 V single phase. At 208 V, output becomes 6.8 kW at 32.6 A.
Which accessories are supplied?
30 psi relief valve, drain valve, temperature and pressure gauge, automatic air vent, UltraSmart controller and outdoor sensor, in addition to the heating elements.
What warranty does Thermo 2000 offer?
15 years on the tank and coils in residential use (10 years in commercial use) and 2 years on electrical and mechanical components and accessories.
A 9 kW AltSource 50, 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.