A wall mounted space heater is hardwired, so its wiring and clearances come from that model’s own nameplate and manual. Stelpro’s Pulsair fan heater demands 36 inches of clear space in front, 8 inches on each side and 8 inches off the floor.
Cadet’s Com-Pak asks for 4.5 inches off the floor and three quarters of an inch beside the grille.
Those are not close. No generic clearance figure exists for this category.
Voltage decides your wire and your breaker
Stelpro builds the Pulsair from 500 W to 2,000 W across 120 V, 208 V, 240 V and 277 V. The heat output does not care which one you pick.
The current does. A 1,500 W element draws 12.5 amps at 120 V and 6.25 amps at 240 V, which is why 240 V dominates hardwired heating.
Stelpro says to protect the unit with the breaker or fuse on its nameplate, and to ground it. The manual puts installation with a certified electrician working to local codes.
Cadet’s own instructions flag the wiring trap here. On a 240 V heater you cover the white supply wire with black electrical tape, because it is a second hot leg and not a neutral.
On the 120 V version of the same heater, that white wire really is the neutral and connects straight through. Same enclosure, same grille, opposite wiring.
Both makers want at least 6 inches of cable left inside the box, with the ground on the green screw. If an electrician is already coming, that visit is when to price in-wall controls electricians actually recommend.
Cutouts, wall depth and the stud
The Pulsair recesses into an opening of 6.5 by 14.625 inches and needs a wall at least 2.375 inches deep. Cadet’s Com-Pak cutout is 10.125 inches tall by 8 inches wide, cut next to a stud.
Measure the cavity before buying. A slim-line unit fits a 2×4 wall, but the opening size is fixed.
Stelpro also tells you to avoid mounting in an exterior wall, since recessing the housing reduces that wall’s insulation. Neither manufacturer wants the heater on a wall behind a door.
More watts does not mean hotter air
This is the spec most buyers misread. Stelpro publishes heat rise beside wattage: the 1,000 W Pulsair gives a 79 F rise, the 1,500 W model only 63 F.
The reason is airflow. The smaller model moves 40 CFM, the larger 75 CFM, so the bigger element spreads its heat across nearly twice the air.
Total output still rises with wattage. Stelpro’s table gives 3,413 BTU/h at 1,000 W, 5,119 BTU/h at 1,500 W and 6,825 BTU/h at 2,000 W.
So read both columns. High heat rise means concentrated warmth from a narrow grille; high CFM at the same wattage means a room that evens out faster.
What the safety hardware does when it trips
The Pulsair carries thermal protection with automatic reset plus a separate thermal fuse. The fuse matters, because Stelpro says it must be replaced once triggered.
A pilot light shows the thermal protection has fired. Blocked airflow is the usual cause, which is what the 36-inch front clearance prevents.
The National Fire Protection Association sets the same three-foot rule for combustibles near heating equipment. Blankets, laundry baskets and papers all sit on Stelpro’s keep-away list.
When a hardwired unit is the wrong answer
Hardwiring costs an electrician visit and a breaker slot, and the heater then stays put for good. For a room you heat occasionally, a plug-in unit from our portable heater roundup does the same job with no install.
Either way the running cost is the wattage, not the mounting. A smart thermostat that lowers the main setpoint is what turns zone heat into a saving.
Frequently asked questions
Does a wall mounted space heater need its own circuit?
Follow the nameplate. Stelpro specifies breaker or fuse protection matched to that plate, and sizing it belongs to the certified electrician, not to a spec sheet.
Can I install one in an exterior wall?
Stelpro advises against it, because recessing the housing cuts into that wall’s insulation. An interior partition wall is the better location.
Why does my new wall heater smell and smoke slightly?
Stelpro’s manual calls temporary odours and thin whitish smoke normal on first start-up or after a long idle. Persistent smoke is not, and means cutting the breaker.
Joyce Lewis covers consumer technology, gaming, and online privacy for 3Zebras. She focuses on the practical side of modern tech, from smartphone tips and app guides to smart device security and the questions readers actually search for.