Big maxx 50,000 heater

[Kenny Jacobs]

I just purchased this and also bought the thermostat for it. The minute I connect the thermostat the fan kicks on then the heat and it just keeps heating even with the thermostat on off. If I disconnect the thermostat it shuts off immediately. I need help! Anybody have some advice?

 

[D45]

2 or 3 wire tstat wire?

Certain you have it wired correctly on the tstat and at the heater?

 

[Kenny Jacobs]

I do have it wired correct. 2 wires red and white. This is the second thermostat I tried. The first did not have an off setting so I bought a mr. heater thermostat. It made no difference. Was in the shop this morning as soon as I plugged into electric it started and the thermostat was turned off. I went ahead and turned it to 55 hoping for a miracle which didn't happen. When it finally reached 70 I cut the gas to let it cool before I cut the electric. Please someone give me the answer. Lol

 

[D45]

Are there any error codes flashing on the board?

 

[ForceFed70]

Sounds like the thermostat is bad. The thermostat that came with my 80,000BTU Big Maxx is super cheap looking so it wouldn't surprise me.

Test without the thermostat. Wires shorted together = call for heat. Wires not connected = off. If it works properly with you shorting/unshorting the wires the problem is definitely with that stat. I'd buy a better quality one from the local hardware store vs trying to get that one replaced.

 

[Kenny Jacobs]

The green light is not flashing any codes. I did unhook the wires from the thermostat and the heater still ran! If I unhook the thermostat wires from the heater it doesn't run. How can that be because when I hook to the heater and unhook from the thermostat nothing is touching to ground it out and it still runs but the second I hook them to the heater it starts!

 

[moserjj]

I'd try a new tstat wire, yours sounds like it's shorted out

Sent from my ONEPLUS A3000 using Tapatalk

 

[Kenny Jacobs]

Ok I found the problem! When I ran the thermostat wires I stapled them and one staple was grounding out the wires. Now I have a bigger problem when I hooked up the new wires I got a spark from the red terminal for the thermostat when I touched the gas pipe and now have no green light!

 

[D45]

Check the fuse on your circuit board

Turn the power off next time

 

[Kenny Jacobs]

It was the fuse on my circuit board. Thanks. Yes the wire was shorted out by a staple. I really am not this dumb all the time guys! Thanks for everyone's input! It eventually turned me to the probem.

 

[D45]

Glad it was a simple and easy fix