THERMO 2000 AltSource 70 Thermal Mass Electric Boiler | 9 kW - 240V
The 9 kW AltSource 70 is a 71 US gal thermal mass electric boiler that heats water up to 88 °C (190 °F), as the backup of a renewable source.
Model numberALTSOURCE70-9
514 316-2973 · sales@airgreen.ca
Quick facts
Cast-iron radiators, a renewable source and a 9 kW backup with 71 US gal of water
The case of plexes heated with hot water
Many Montreal plexes have kept their cast-iron radiators. Owners who add an air-to-water heat pump, or another renewable-energy system, need a backup that can supply those radiators at high temperature. That is exactly the role of the AltSource 70-9: its water can be heated from 50 °F to 190 °F (10 °C to 88 °C), and Thermo 2000 gives specific recommendations for cast-iron radiators, baseboards and radiant floors.
What the AltSource 70-9 is
It is a thermal mass electric boiler, which Thermo 2000 presents as the only high water volume electric boiler on the market. Its tank holds 71 US gal of water. Its 9 kW output at 240 V, or 30,708 BTU/h, comes from two 4.5 kW elements that come on in two stages. The T2 UltraSmart controller, supplied with its outdoor sensor, modulates output and water temperature on the outdoor temperature and shuts heating off in warm weather.
The controller runs in standalone electric mode by default. In automatic transfer mode, an external contact controls the unit when a main source is connected.
What to plan for in the mechanical room
A 71 US gal reserve needs a solid location. The unit weighs 380 lb before it is filled and measures 24 in in diameter and 28 in deep with the door. In a plex basement, we check the stairs, door frames and floor before confirming the location.
On the loop, the AltSource connects in 1 1/4 in male NPT and operates at a maximum pressure of 30 psi. With cast-iron radiators, Thermo 2000 recommends a #90 expansion tank; with baseboards or a radiant floor, a #60. The circulator and tank are not among the supplied parts and are listed in the quote.
On the electrical side, it needs a 240 V single-phase circuit with a 50 A breaker and Cu 8 / Al 6 wire gauge. In a building with a 208 V supply, output becomes 6.8 kW (32.6 A).
From estimate to commissioning
We start with a free on-site estimate: condition of the radiator loop, main source, electrical panel, access. You then receive a written quote. On installation day, we install the boiler, connect it to the loop and the electrical circuit, mount the outdoor sensor and supplied accessories, fill and purge the system, then set the controller.
Thermo 2000 covers the tank for 15 years in residential use and 10 years in commercial 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.
Ask for your free estimate
We serve Montreal, Laval, Longueuil, the North Shore and the South Shore. Receive a written quote for your AltSource 70, with financing available.
An electric backup for radiator systems
With water heated from 50 °F to 190 °F (10 °C to 88 °C), the AltSource 70-9 supplies cast-iron radiators as well as baseboards or a radiant floor. Thermo 2000 designs it as the backup source of an air-to-water heat pump, a geothermal system or solar collectors.
- Plex heated by cast-iron radiators, with an air-to-water heat pump as the main source
- Older house that keeps its radiators and adds a renewable source
- Backup for a geothermal system feeding hot-water baseboards
- Replacing an electric boiler with a large water reserve unit
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- With cast-iron radiators, Thermo 2000 recommends a #90 expansion tank (#60 for baseboards or a radiant floor). Neither the tank nor the circulator is on the list of supplied parts.
- Maximum working pressure of 30 psi (207 kPa): we check the existing loop before connecting.
- The unit weighs 380 lb, plus the water in the tank once filled; it measures 24 in in diameter and 28 in deep with the door.
- 240 V single-phase circuit with a 50 A breaker and Cu 8 / Al 6 wire gauge. At 208 V, output drops to 6.8 kW (32.6 A).
- 30 psi (207 kPa) relief valve
- Drain valve
- Temperature and pressure gauge
- Automatic air vent
- Heating elements
- UltraSmart controller
- Outdoor sensor
Manufacturer documents
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Frequently asked questions
Is it suitable for cast-iron radiators?
Yes. Thermo 2000 covers this case in its recommendations, with a #90 expansion tank, and water can be heated up to 88 °C (190 °F). We check the condition and pressure of the existing loop during the estimate.
What pressure must the loop respect?
The maximum working pressure is 30 psi (207 kPa), and the supplied relief valve is set at 30 psi. The unit is tested at a hydrostatic pressure of 60 psi.
Can it heat without the renewable source?
Yes, standalone electric mode is the default setting of the T2 UltraSmart controller. Automatic transfer mode is used when a main source is connected.
What electrical circuit is needed?
A 50 A breaker and Cu 8 or Al 6 wire gauge, at 240 V single phase, according to Thermo 2000.
Which standards are listed?
Thermo 2000’s specification sheet lists CSA C22.2 No. 165-92 for Canada and UL 834 for the United States.
A 9 kW AltSource 70, 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.