THERMO 2000 ComboMax Ultra 50 Electric Boiler with Integrated Hot Water | 9 kW - 240V
A 9 kW electric boiler and an instantaneous water heater in the same 48 US gal tank: Thermo 2000’s ComboMax Ultra 50.
Model numberCOMBOU50-9
514 316-2973 · sales@airgreen.ca
Quick facts
Two appliances replaced by one: 9 kW of heating and instantaneous hot water in 48 US gal
The typical case: a boiler and a water heater side by side
In many basements in Montreal and Longueuil, it is the same scene: an electric boiler on the wall, a water heater beside it, pipes crossing between the two. Thermo 2000’s 9 kW ComboMax Ultra 50 does the work of both. It heats the home’s hot-water loop and makes domestic hot water, in a single 48 US gal tank that takes the space of a conventional water heater: 60 in high and 22 in in diameter.
The principle is simple. The tank holds the heating water. Parallel copper coils are immersed in it; drinking water flows through them and heats up on the way. No domestic hot water is stored, which, according to the manufacturer, reduces the risk of Legionella. Water arrives hot in under 7 seconds, again according to Thermo 2000.
9 kW on two identical elements
Heating relies on two 4.5 kW elements split over two stages, for 30,708 BTU/h at 240 V. This size suits a medium-sized home heated by radiators, hot-water baseboards or radiant floors, once the heating load is confirmed. For hot water, Thermo 2000 publishes 55 US gal in 10 minutes and 99 US gal in one hour, at 110 °F, with cold water at 40 °F and boiler water at 180 °F.
The T2 UltraSmart controller gives priority to domestic hot water, sets its temperature and runs the heating pump when the thermostat calls. The required electrical circuit is 240 V single phase with a 50 A breaker and Cu 8 or Al 6 wire; at 208 V, output is multiplied by 0.75 according to the manufacturer.
An installation planned from start to finish
- Free on-site estimate, in Laval, on the South Shore, the North Shore or in Montreal: we note the heating load, your hot water needs, the panel’s capacity and the location.
- Written quote: unit, loop components, removal of the old appliances if needed, steps of the work.
- Installation: setting in place, connection by qualified personnel to the heating loop (1 in male NPT) and to domestic water (3/4 in female NPT), then the electrical connection.
- Start-up: filling, purging, setting the controller and testing heating and hot water.
Several accessories supplied by Thermo 2000 arrive already mounted, including the 12 psi pressure regulator with check valve, the thermostatic mixing valve and the automatic air vent. AirGreen is a family business established in Montreal for more than fifteen years, holding RBQ licence 5645-9605-01 (ventilation, refrigeration and electrical).
Warranty and next step
Thermo 2000 covers the tank and coils for 15 years in residential use (10 years in commercial use), and electrical and mechanical components for 2 years.
Free up your mechanical room: ask for a free estimate and a written quote for the 9 kW ComboMax Ultra 50, with financing available.
One appliance where there used to be two
The COMBOU50-9 does the work of an electric boiler and a water heater. Its two 4.5 kW elements heat the 48 US gal of water in the tank, where copper coils heat drinking water as it passes.
- Mechanical rooms where a boiler and a water heater share the space
- Homes heated by radiators, hot-water baseboards or radiant floors
- Owners who want a single appliance to maintain
- Basement renovations that need floor space
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- 50 A breaker and Cu 8 / Al 6 wire at 240 V single phase, according to Thermo 2000; at 208 V, output is multiplied by 0.75.
- 325 lb empty, plus the water in the tank once filled: the floor must carry that load.
- Maximum working pressure: 30 psi (207 kPa) for heating and 125 psi for domestic water. The supplied pressure regulator is 12 psi.
- 1 in male NPT heating connections and 3/4 in female NPT domestic water connections.
- 30 psi heating relief valve
- 125 psi domestic hot water relief valve
- Tank and heat exchanger drain valves
- Temperature and pressure gauge
- Automatic air vent
- 12 psi pressure regulator
- Check valve (ASSE 1012 / CSA B64-3)
- Thermostatic mixing valve
- Heating elements and T2 UltraSmart controller
Manufacturer documents
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Frequently asked questions
Can I remove my current water heater?
Yes, that is the whole idea of the ComboMax Ultra: it makes domestic hot water as well as heat. We first check that its output (55 US gal in 10 minutes, 99 US gal in one hour at 110 °F, with cold water at 40 °F and boiler water at 180 °F) covers your needs.
How much space does it take?
60 in high and 22 in in diameter, the space of a conventional water heater according to Thermo 2000. It weighs 325 lb empty.
What breaker is needed?
Thermo 2000 specifies a 50 A breaker and Cu 8 or Al 6 wire on a 240 V single-phase circuit.
What pressures does it handle?
30 psi (207 kPa) maximum on the heating side and 125 psi on the domestic water side. The supplied 12 psi pressure regulator comes with a check valve.
What does Thermo 2000’s warranty cover?
The tank and coils: 15 years in residential use, 10 years in commercial use. Electrical and mechanical components: 2 years.
Replace two appliances with a 9 kW ComboMax Ultra 50
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.