Electronic Thermostat STELPRO ST402NPFF 4000 W | Montreal, Laval, Longueuil, South Shore and North Shore

A finished basement with a high ceiling, a workshop, a large building entrance or a small commercial space: some spaces are heated by high-capacity fan heaters that can warm a large volume of air quickly. These units need a thermostat that can handle the load and knows how to manage the fan. The Stelpro ST402NPFF fits the bill. This non-programmable electronic thermostat handles up to 4000 W at 240 V of fan heater load, with a 3-wire connection, Boost mode, ECO mode and Lobby mode. At AirGreen, we install it in large spaces where people want simple, sturdy control.

The right control for high-capacity fan heaters

The ST402NPFF runs on 120, 208 or 240 V. Its load range goes from 150 to 2000 W at 120 V, 260 to 3475 W at 208 V and 300 to 4000 W at 240 V. That capacity lets it control one powerful fan heater, or several units on the same circuit, in spaces that smaller models couldn't handle.

Boost mode in a large space

In a cold basement or a workshop, waiting for the temperature to come back up can take a while. Thanks to its 3-wire connection, the ST402NPFF offers Boost mode, which speeds up the temperature rise. You walk into the workshop, turn on Boost, and the space is usable in no time. Once the setpoint is reached, normal control resumes.

ECO mode between uses

Large spaces heated by fan heaters are often used on and off: a workshop used in the evenings and on weekends, a basement used for hobbies, a commercial entrance that's busy during business hours. ECO mode lets you lower the temperature with one touch between uses, with no programming. Paired with Boost mode, it makes an effective combo: a lower temperature most of the time, and a quick warm-up when you want it.

Lobby mode

Lobby mode is designed for entrance halls and spaces people pass through. In an apartment building or a store, entrances heated by fan heaters have their own needs, and this mode lets you set the thermostat up for that kind of use.

Accuracy, display and compliance

Thermistor sensing holds the temperature within ±0.5 °C (1 °F), over a setpoint range of 5 to 30 °C (41 to 86 °F). The digital display can be set to °C or °F. The thermostat is certified to CSA C828-19 and comes in a white moulded plastic housing.

Typical spaces

You'll find the ST402NPFF in finished basements heated by a recessed fan heater, home workshops, insulated and heated garages, rec rooms, building entrances and small shops. What these spaces have in common is a large volume of air to heat and occupancy that varies. Sturdy, accurate manual control paired with a powerful fan unit gives excellent results there, without making things complicated for the people using it.

Choosing within the FF series

The ST402PFF shares the 4000 W capacity and Boost mode, but adds a programmable schedule with 4 periods on weekdays and 2 on weekends, so it suits spaces used on a regular schedule. The ST252NPFF offers the same features as the ST402NPFF with a 2500 W capacity, for the smaller fan heaters found in bathrooms and small entrances. The ST402NPFF is the right choice for a large space with irregular use.

Technical specifications

• Type: non-programmable line-voltage electronic thermostat for fan heaters
• Systems: electric fan heaters (3-wire)
• Voltage: 120/208/240 V
• Load range: 150 to 2000 W at 120 V; 260 to 3475 W at 208 V; 300 to 4000 W at 240 V (max. 4000 W at 240 V)
• Features: ECO mode (temperature setback), Boost mode (fast rise, 3-wire connection), Lobby mode
• Accuracy: ±0.5 °C (1 °F), thermistor sensing
• Setpoint: 5 to 30 °C (41 to 86 °F)
• Display: digital, °C or °F (your choice)
• Certification: CSA C828-19
• Colour: white, moulded plastic

Professional installation and tips for use

Before installation, our qualified technicians note the wattage of the fan heater, or of the group of units being controlled, to confirm it stays within the 4000 W capacity at 240 V. Then they check that three conductors are available at the thermostat box. The circuit is shut off at the panel, we confirm there's no voltage, and the thermostat is wired and mounted. Once the power is back on, we test the heating, the fan and Boost mode, and show you how ECO mode and Lobby mode work.

In a workshop or a finished garage, we also pay attention to where the thermostat goes: it has to be away from the unit's direct airflow, exterior doors and spot heat sources, so it reads a temperature that reflects the whole space.

Saving energy in large spaces

A large volume of air is expensive to heat. Keep ECO mode on when the space isn't in use, and only use Boost when you walk in. In a building entrance, a moderate setpoint is enough; a high one would only be fighting the cold air that comes in every time the door opens. If the space is used on a fixed schedule, consider the programmable ST402PFF, which handles these setbacks automatically.

Maintenance

Fan heaters in workshops and entrances build up dust and debris quickly. Clean the grille and the fan at the start of every heating season. Don't store things or materials in front of the unit, since that blocks the airflow and throws off the thermostat's reading. The thermostat itself only needs dusting.

Why AirGreen

AirGreen is a family-owned HVAC company with an RBQ licence, more than 15 years of residential and commercial experience and a showroom in Boucherville. To buy the Stelpro ST402NPFF thermostat and have it professionally installed, get in touch with us. We serve Montreal, Laval, Longueuil, the North Shore and the South Shore.

Stelpro documents

Stelpro spec sheet (PDF) · Stelpro user guide (PDF)