Home Improvement Today?

It looks like a simple inline thermal switch. I cant seem to get a clear enough picture to see what the back looks like but it would, in theory, break the hot line to the heater. If the actual temperature lowers below the set temperature, it closes the switch allowing the heater to turn on. When the temp raises to the set temp, the switch opens turning off the heater. The closest I could find is this manual 4 wire model from Honeywell. Page 4 shows the 2 wire setup. I would suspect that this older model is wired similarly. It must be said that I am not an electrician by trade but I did say at a Holiday Inn last night.

-J

 

I don't know the specs on the fan as it's mounted up in the attic space. I didn't try to remove the grate.

 

But wouldn't the temp set on the thermostat open the circuit and thus turn on the fan?

 

https://www.grainger.com/product/RA...-3ZP77?opr=PDPRRDSP&analytics=dsrrItems_3ZP81


This is should cover most* residential exhaust fans, and you can run the thermo-probe close to where you want to monitor it.

Edit***
This is another option if the amp draw is under 6Amps https://www.grainger.com/product/HONEYWELL-Fan-Coil-Thermostat-Fan-Coil-3RCK7 But on the pricy side.

 

What you want is a cooling relay, CLOSE on rise. Most line voltage thermostats are OPEN on rise cutting the power. The thermostat you currently have there is a dual action (mine is also dual acting). If you read the back of your thermostat it says COM, HEAT, COOL that is because on Heat the contact is made when the temperature falls below the setpoint (temperature setting) on Cool the contact is made when the temperature rises.

 

Definitely a line voltage thermostat. However, that needs to be in an outlet box, not a low voltage box. They make them in digital, but aren't something readily available at the big box stores.

 

Do they want a programmable t-stat or just a digital one? Both seem kind of silly for the application you have described.

A basic mechanical line voltage t-stat in that application works well (and is cheap too!), I have set up several just that way, although I used the correct j box to mount it.

 

They want to upgrade to a non programmable digital. The current one is also not working properly. They fan isn't kicking on at the temperature they set

 

There is an outlet box. What's there seems to be a thin plastic insert of some sort. Should have noted that.

 

I bet you could recalibrate it using the same pdf I linked above. I wouldnt see how different the innards would be since it's a simple switch.

-J

 

For what it’s worth I think I paid $38 for mine.

 

Just want to replace the existing with a new one.

 

I'll start with the thermostat before tackling the fan and duct work.

 

...^^^... FWIW ... A couple of years ago, I bought a 5 Gallon JustRite Safety Can - close to $100.00 and it had a small blemish in the weld (wire stuck in the weld).

Took pics and Amazon sent me a new can and ask me to destroy the old one. Great service

 

Exact same thing/experience happened to me a few years back. Except mine simply had a small dent.

One is none and two is one.

 

Mark this stat should work fine for this application
https://www.supplyhouse.com/White-R...00-p?msclkid=f545c2357b3f1b3e5215a17a5574ae25

 

That's heat only. He needs a cooling one.

 

well shit thats not the one I picked.... hold on

 

Made some progress on the greenhouse. No caulk involved. Yet.

 

Robertshaw 803A will replace what is there. Supply House is a good outfit too.

https://www.supplyhouse.com/Roberts...9n1yL8Yv2cDfnbhUmRlFI2Gi-2hW-PNgaAvI0EALw_wcB

Or for 6 times the money you can get this one from Johnson Controls. At that price it might be considered "A Big Johnson"...

https://www.supplyhouse.com/Johnson-Controls-T26J-7C-75-to-90F-Cooling-Line-Voltage-Thermostat