THERMO 2000 Mini BTH 3 Electric Boiler | 3 kW - 240V
The Mini BTH 3 is Thermo 2000’s smallest wall-mounted electric boiler: 3 kW to heat a room, a radiant floor or a small unit with hot water.
Model numberMINI BTH 3
514 316-2973 · sales@airgreen.ca
Quick facts
3 kW of gentle hot water heat, in a boiler that fits on a wall
The smallest Mini BTH, for small zones
Not every heating zone needs a big boiler. A radiant floor in the basement bathroom, a room added at the back of the house, a small condo heated by hydronic baseboards: for these modest loads, Thermo 2000’s Mini BTH 3 does the job with a single 3 kW element, or 10,236 BTU/h at 240 V.
Its body holds only 1 US gal of water. Thermo 2000 describes it as very compact, multi-position and quiet, designed for condos, houses, basements and garages. It mounts on the wall and connects through four 3/4 in female NPT connections. The manufacturer also presents it as backup for a heat pump, a geothermal or a solar system, with no GHG emissions.
A simple electrical connection
At 240 V, the Mini BTH 3 draws 12.5 A. Thermo 2000 specifies a 20 A breaker and Cu 12 or Al 10 wire. In a Montreal condo or a Laval home where the panel is already well filled, this small load fits in more easily than a larger boiler. If the building is supplied at 208 V, output becomes 2.2 kW (10.9 A): we take that into account from the estimate.
The control is deliberately simple: an aquastat sets the water temperature, an indicator light shows when the element is heating, a switch turns the appliance on or off, and a 24 V supply serves the thermostat and accessories. There is no outdoor sensor. Two high temperature limits protect the appliance: automatic at 208 °F (98 °C) and manual at 227 °F (108 °C).
What to plan around the boiler
Thermo 2000 supplies the 30 psi relief valve, the drain valve and the temperature and pressure gauge. The circulator and expansion tank are not included: they are chosen for the circuit to be heated, and we list them in the quote. The maximum working pressure is 30 psi (207 kPa).
Installation by AirGreen
We first come for a free on-site estimate: area to heat, type of distribution, electrical panel, wall location. You then receive a written quote. On installation day, our technicians mount the boiler, install the circulator and expansion tank, connect the water circuit, make the electrical and thermostat connections, then fill, purge and check operation with you.
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. Thermo 2000 warrants the tank for 15 years and the electrical and mechanical components for 2 years.
Heat your small zone
We install the Mini BTH in Montreal, Laval, Longueuil, on the North Shore and on the South Shore. Ask for your free estimate: the quote is in writing, and financing is available.
A small boiler for a small heating zone
The Mini BTH 3 heats the water of a hydronic circuit with a single 3 kW element, controlled by an aquastat. It hangs on the wall and suits spaces with little room and modest needs.
- Radiant floor in a bathroom or a basement room
- Small condo heated by hydronic baseboards
- Addition served by its own hot water circuit
- Backup for a heat pump, geothermal or solar system on a small load
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- Dedicated 240 V single-phase circuit: 20 A breaker and Cu 12 / Al 10 wire, according to the manufacturer.
- At 208 V, output drops to 2.2 kW (10.9 A).
- The circulator and expansion tank are not included: they are selected and supplied at installation.
- Aquastat control, no outdoor sensor: the water temperature does not adjust to the weather.
- Maximum working pressure of 30 psi (207 kPa).
- 30 psi relief valve
- Drain valve
- Temperature and pressure gauge
- Installation manual
Manufacturer documents
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Frequently asked questions
Is a 3 kW boiler enough?
For a small zone, yes: a bathroom radiant floor, a basement room or a small, well-insulated condo. It delivers 10,236 BTU/h at 240 V. A whole house generally needs a larger size in the series; we confirm it during the free estimate.
Where can it be installed?
On a wall, in a mechanical room, a closet or a basement. Thermo 2000 describes it as quiet and suited to condos, houses, basements and garages.
What needs to be added to the boiler?
A circulator and an expansion tank, which are not included, plus the zone thermostat. The 30 psi relief valve, the drain valve and the temperature and pressure gauge are supplied.
Can it back up a heat pump?
Yes. Thermo 2000 designs the Mini BTH as backup for a heat pump, a geothermal or a solar system. At 3 kW, it suits a small load.
What warranty does Thermo 2000 offer?
15 years on the tank and 2 years on electrical and mechanical components, in Canada and the United States.
A 3 kW Mini BTH, 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.