CONFORTO AT AT4000 Electric Boiler | 40 kW - 240V
The Conforto AT4000 is the largest system of the AT series: two electric boilers installed in parallel, 40 kW at 240 V and 136,400 BTU/h according to the manufacturer.
Model numberAT4000
514 316-2973 · sales@airgreen.ca
Quick facts
40 kW of hot-water heating, all on electricity
When to choose the AT4000
The Conforto AT4000 is the largest system of the AT series: two electric boilers installed in parallel totalling 40 kW at 240 V, or 136,400 BTU/h according to the manufacturer. Conforto’s brochure lists it under the code AT400010C15. It takes over where the AT3200 is no longer enough.
It is found in buildings that need a lot of heat: a Montreal apartment building heated by a shared radiator loop, a South Shore workshop or commercial space with a heated slab, a very large residence. It is also the option to consider when replacing an existing two-boiler electric system.
Two boilers, one control logic
Both units are AT series wall-mounted boilers of about 70 lb (32 kg) each as shipped, connected with 1 1/4 in NPT fittings. Their controller works in stages, with element rotation, and its immersion sensor at the heat exchanger outlet prevents short cycling. It manages a heating setpoint and a domestic hot-water setpoint with priority for an indirect water heater, includes freeze protection and accepts a flow switch, a low-water device and a load-management input for the electricity provider.
Electricity and space, planned first
At 40 kW, the building’s electrical service is the first issue to settle. Conforto publishes the electrical data of each of the two boilers, not of the complete system; we derive the supply required and compare it with the existing service before any recommendation. Wall space for two units and parallel piping must also be planned. Since no minimum flow is published for the whole, we check the loop against the requirements of each boiler.
Conforto’s limited lifetime warranty covers indoor residential use in Canada; for commercial use, the manufacturer provides 2 years on parts and 10 years on the heat exchanger. Yearly maintenance is required.
What AirGreen’s installation covers
We start with a free on-site estimate, confirm the exact make-up of the system before ordering and give you a written quote that covers the boilers, the piping, the power supply and any upgrade needed. In an occupied building, we plan the draining steps with you to reduce the time without heat.
Our technicians mount both boilers, make the connections, fill and purge the loop, commission the system and set the setpoints. AirGreen is a family business established in Montreal for more than fifteen years, RBQ licence 5645-9605-01.
Property managers and owners in Montreal, Laval, Longueuil, the North Shore and the South Shore: ask for your free estimate and your written quote. Financing is available.
The largest system of the Conforto AT series
The AT4000 brings together two AT series boilers installed in parallel to reach 40 kW. It is the top of the series, above the AT2800 and the AT3200.
- Apartment building heated by a shared radiator loop
- Commercial space, workshop or office heated by a radiant floor
- Very large residence whose heating demand exceeds the other sizes
- Replacing an existing two-boiler electric system
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- Two wall-mounted boilers of about 70 lb (32 kg) each as shipped, connected with 1 1/4 in NPT fittings: space and parallel piping are planned at the design stage.
- Conforto publishes the electrical data of each boiler, not of the complete system. At this output, the building’s electrical service must be assessed first.
- No minimum flow is published for the complete system; we check the loop against the requirements of each boiler.
- Staged control, without modulation; the manufacturer’s documents do not mention an outdoor sensor.
- Limited lifetime warranty for indoor residential use in Canada; commercial use: 2 years on parts, 10 years on the heat exchanger. Yearly maintenance required; labour and shipping excluded.
Manufacturer documents
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Frequently asked questions
When should I choose the AT4000 over the AT3200?
When the building’s heat needs exceed what the AT3200 (32 kW) supplies. The AT4000 delivers 40 kW, or 136,400 BTU/h at 240 V according to Conforto. We assess the needs on site before recommending a size.
Will the building’s electrical service be enough?
That is the first thing we check. Conforto publishes the electrical data of each of the two boilers; we derive the supply required and compare it with the existing service. The written quote states any upgrade needed.
Which boilers are delivered?
Two AT series boilers, installed in parallel. We confirm the exact make-up before ordering and write it into the quote.
Which warranty applies to commercial use?
Conforto provides 2 years on parts and 10 years on the heat exchanger. The limited lifetime warranty covers indoor residential use in Canada. Yearly maintenance is required; labour and shipping are excluded.
Can you install the system in an occupied building?
Yes. We plan the work with you and announce in advance the steps that require draining the loop, to reduce the time occupants go without heat.
A 40 kW Conforto system, 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.