THERMO 2000 ComboMax Ultra 50 Electric Boiler with Integrated Hot Water | 7.5 kW - 240V
Thermo 2000’s 7.5 kW ComboMax Ultra 50: a two-stage electric boiler and an instantaneous water heater combined in a 48 US gal tank.
Model numberCOMBOU50-7,5
514 316-2973 · sales@airgreen.ca
Quick facts
Two heating stages and all the home’s hot water, in a 48 US gal tank
A boiler that does not always run flat out
In October, a house does not need the same heat as in January. Thermo 2000’s 7.5 kW ComboMax Ultra 50 meets that reality with two elements of different ratings, 3 kW and 4.5 kW, on two stages. Heat is added step by step, up to 25,590 BTU/h at 240 V, instead of switching on full output at once.
The same appliance makes domestic hot water. Parallel copper coils sit in the 48 US gal of heating water in the tank; drinking water flows through them and heats up on the way, without being stored. Thermo 2000 publishes 53 US gal of hot water in 10 minutes and 90 US gal in one hour, for water delivered at 110 °F, cold water at 40 °F and boiler water at 180 °F.
The homes it suits
This size is aimed at bungalows and small two-storey houses heated by hot-water baseboards, radiators or radiant floors, in Laval, on the South Shore and in Montreal. It is above all for owners who want a single appliance to maintain for heating and hot water. The tank takes the space of a conventional water heater, 60 in high and 22 in in diameter, and the unit weighs 325 lb empty.
The T2 UltraSmart controller, with its backlit display, manages domestic hot water temperature, gives it priority and runs the heating pump when the thermostat calls. The thermostatic mixing valve, already mounted, tempers the water sent to the taps. Thermo 2000 announces an expected service life of more than 30 years and minimal maintenance.
Electrically, plan a 240 V single-phase circuit with a 40 A breaker and Cu 8 or Al 6 wire. In a building supplied at 208 V, the manufacturer states that output is multiplied by 0.75.
What AirGreen’s installation covers
- A free in-home estimate, in Longueuil, on the North Shore and throughout Greater Montreal: heating load, hot water needs, electrical panel and location.
- A written quote specifying the unit, the loop components and each step of the work.
- Setting the unit in place and connecting it, by qualified personnel, to the heating loop (1 in male NPT) and to domestic water (3/4 in female NPT).
- The electrical connection, filling and purging the loop, setting the controller and a full test of heating and hot water.
AirGreen is a family business established in Montreal for more than fifteen years, holding RBQ licence 5645-9605-01 (ventilation, refrigeration and electrical). Thermo 2000’s warranty covers the tank and coils for 15 years in residential use (10 years in commercial use) and electrical and mechanical components for 2 years.
Next step
Book your free estimate: we give you a written quote for the 7.5 kW ComboMax Ultra 50, with financing options.
Two heating stages to follow the seasons
With one 3 kW and one 4.5 kW element on two stages, the COMBOU50-7,5 does not always switch on its full output. The same 48 US gal tank heats the home’s loop and the drinking water, which flows through copper coils without being stored.
- Bungalows heated by hot-water baseboards or radiant floors
- Homes that want a single appliance for heating and hot water
- Mechanical rooms with only enough space for a water heater
- Replacing an electric boiler at the end of its life
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 40 A breaker and Cu 8 / Al 6 wire, according to Thermo 2000.
- At 208 V, output is multiplied by 0.75 and current by 0.867, according to the manufacturer.
- Footprint: 60 in high, 22 in in diameter, 325 lb empty.
- Thermo 2000’s documents do not mention an outdoor sensor for the ComboMax Ultra: do not count on weather-based control.
- 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
What are the two stages for?
The COMBOU50-7,5 has two elements, 3 kW and 4.5 kW, on two stages. Output is added step by step instead of switching on all 7.5 kW at once.
What electrical circuit is needed?
A 240 V single-phase circuit with a 40 A breaker and Cu 8 or Al 6 wire, according to Thermo 2000. We check your panel’s capacity during the free estimate.
What runs the heating pump?
The T2 UltraSmart controller. It starts the pump when the thermostat calls for heat and gives priority to domestic hot water when it is being drawn.
Which accessories are supplied?
Thermo 2000 supplies the heating (30 psi) and hot water (125 psi) relief valves, the drain valves, a temperature and pressure gauge, an automatic air vent, a 12 psi pressure regulator, a check valve, the thermostatic mixing valve and the controller. Several are pre-mounted.
What warranty does the manufacturer offer?
Tank and coils: 15 years in residential use, 10 years in commercial use. Electrical and mechanical components: 2 years. This is the warranty published by Thermo 2000.
The 7.5 kW ComboMax Ultra 50, installed in your home 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.