Window fan: Bypassing thermostat with a button

[DaveC426913]

TL;DR

Bought this cheap window fan. Want to bypass the thermostat with an on/off button.

I bought this window fan for my work shed. Installed it on a nice, mild day. Next day fan wouldn't work. Almost took it back to the store before realizing the day was much colder. The fan is on a thermostat - one that's probably set for summer, not winter.

So, I want to be able to operate it in near-freezing temps. Rather than ripping out a perfectly good thermostat function, I'd like to just press a button to bypass it.

Plaque on back says it draws 120V and .7A. It has 2 independently-controlled fans, each with 0-1-2-3 settings. (Hopefully, the .7A is at max output). Thera are very small, low speed plastic fans.Here is the thermostat. It appears to be first in line in the circuit (or last. I haven't checked which side is hot yet). Before opening it up, I'd assumed the thermostat would be on a very low voltage part of the circuit, merely controlling a solenoid or something, but it turns out it's directly in the power circuit, and therefore I will need a 120v jumper and switch.

I don't know if there is a way to adjust the stat, not that I saw. That would solve my problem real quick.

I am thinking of putting in an on/off push button or toggle that will short circuit the thermostat if I want to the fan to be on at any temperature.

(The fan runs off the work shed power bar, so it will only be on when I am in there with the power on.)You guys always seem to come up with solutions I hadn't thought of.

 

[berkeman]

I'm pretty sure I've passed this EE tip on to you in the past, but whatever. Just substitute the fuses, and you'll be fine.

View attachment 1703537224233.webp

 

[Tom.G]

I suggest using either a toggle switch or a slide switch, they tend to be a little more reliable than the commonly available alternate-action (latching) pushbuttons.

Cheers,
Tom