Garage Heater Installation and Wiring

With the hunting season upon us, I decided it was time to finally install a permanent heating system in the shack. We've used a propane heater for years but it's always either way too warm or way too cold. We also have to change out tanks at night or run into town in the morning when we realize we're out. This year doesn't look too cold, but I figured better to get it all setup just in case.

I purchased a Dyna-Glo X7500 from Menards. It's rated at ~22,000 BTUs and 7500 watts and should heat the entire building. It states 750 square feet, and the shack is just over 600.

At 7500 watts and 240V, I needed to install at least a 40 AMP double pole breaker with 8 Guage wire. The math is 7500 / 240 = 34 AMPs. Breakers need to be 120% of maximum load so 1.2 * 34 = 40.8 AMP. I ended up with a 50 AMP breaker just to be sure. The panel is QO and Menards included a homeline breaker in my order and I didn't notice. Queue one trip to the local Ace hardware.

First, I mounted the heater on the ceiling using one of the cross beams. I removed one of the screws used for the metal, drilled a larger hole and hung the mount and screwed the heater to the mount.

I then ran the wire from the heater down to the breaker box. I secured the wire to the ceiling and wall with wire clamps.

I tied the wire into both the heater and the breaker with wire connectors.

Wiring the heater was straight forward. Both the white and black go to the L1 and L2 connections and the bare ground goes to a nut on the heater. Installing the breaker was also pretty easy, albeit a bit spooky being close to that main line. I removed the panel door, turned off the main and clipped in the breaker. From there, I connected the white and black to both leads of the breaker.

I ran the ground around the panel to the ground bar.

After everything was hooked up, I cautiously turned on the main and new breaker. No sparks! That said, the heater would only display L when pressing the power button on the unit or the remote. After more time than I care to admit trying to troubleshoot the problem, I realized there was a switch on the back of the unit to turn it on.

Once it was actually on, I set the heat to 70 F and ran it for about 45 minutes to see how it worked. It was able to heat the shack from 58 F to 70 F over that time. Pleasantly surprised.