240 v garage heater

[WoodworkerTom]

I bought a 240v 7500watt ceiling mount heater so I can build cabinets over the winter. Power requires 40 amp breaker. I have a shut off swith from my dads shop rated for 100 amps. Overkill I know but it was free. Darn thing is almost the size of the subpanel.

Rather than go through the trouble to install the switch could I turn the heater on and off with the breaker at the subpanel or is that a bad idea?

[blackhat]

Standard breakers are not designed to be used as a switch.

[Robert Adams]

I think he is referring to a disconnect switch not breakers.

I have a 400 amp three paradise one that Is going to become a cabinet in the shop.

[brofessor]

You could use the breaker but be aware over several years of use it will wear down. And a 40 amp breaker isn't really cheap. You might be better off just installing the heavy duty switch. But if you'd rather use the breaker and you don't use it all that often it may last a long time.

[Estrogen Hostage]

I have one in the shed. Pay shipping and it's yours. Iirc, it's rated at 60 amps.

[3finger]

I have a similar heater in my shop in a stand-alone building in my back yard. This may be more trouble and expense than you want, but the thermostat/switch combo on my heater blew not long after I got it, so I replaced it with a wall mounted thermostat. To do this, I got a contactor rated for 40 amps with a 24v coil to switch the heater on and off and a cheap 24v transformer to power the thermostat. I find this works a whole lot better than the thermostat/switch mounted directly on the heater, as the temperature is more consistent and the unit doesn't cycle on and off nearly as much.

Because my shop is separate from the house, I went one step further and installed a wireless thermostat that I can control with my cellphone. I can warm up the shop in the winter without having to trudge through the snow beforehand.