Mr. Heater Big Maxx heater not working

[Bbp78]

Hi all, happy holidays. I’m hoping someone can guide me. I have a Mr. Heater Big Maxx F260560 unit heater that is not igniting. It was installed in my shop almost 4 years ago and this year I finally got a propane tank installed and finished hooking everything up last week. I finally decided to fire it up yesterday and it is not working or anything. The LED codes are blinking a steady green which appears to mean “Normal operation - no call for heat”. There are no blocks anywhere as it’s never been used and I bled the air and the propane is at the heater, so I’m not sure what the issue is. I should probably pay someone but thought I’d check with you guys first as everything is brand new. Any ideas? Should I try a new thermostat even though the one I have is brand new? Thanks in advance for any guidance, it’s appreciated.

 

[allinon72]

No call for heat means it's not going to start the ignition sequence. Double check thermostat wiring and thermostat.

 

[Bert_]

Wonder how many heater threads we can start?

Same **** different pile... Get out the volt meter and start testing!

You should have a terminal strip somewhere. R = 24v, W = call for heat, C = common. Not all heaters will have the common available.

 

[Bbp78]

Thank you Bert and Allinon72, I will try to check tomorrow. I appreciate it!

 

[larry4406]

At the day job, I sometimes bypass the thermostat and jumper red to white on the board to get the furnace on.

 

[Bbp78]

At the day job, I sometimes bypass the thermostat and jumper red to white on the board to get the furnace on.

Thanks for your reply larry4406. When you say bypass the thermostat, do I unhook the wires from the thermostat and just leave those hanging and hook up the ones on the board on the heater? I’m a little confused, lol. Thanks

 

[Bbp78]

Wait, I’m reading this again and seeing it more clearly. I guess I was getting sidetracked with my kids opening presents this morning, haha. Okay so I’ll get a jumper piece to connect the red and white on the board on the heater like you stated. Thanks

 

[dscheidt]

Wait, I’m reading this again and seeing it more clearly. I guess I was getting sidetracked with my kids opening presents this morning, haha. Okay so I’ll get a jumper piece to connect the red and white on the board on the heater like you stated. Thanks

I usually start at the thermostat. First I replace the battery if it’s got one. Thermostats act weird with a low battery. Mine looks like it is calling for heat, but it doesn’t close the contacts. Others just stop calling for heat. Then I check the wiring to it, because I’ve seen loose wires, and on a new install that’s quite possible. Then I jump to force a call for heat. If it fires from there, the wiring to the unit is fine, and I figure out what is wrong with the tstat. If it doesn’t, go jump at the unit.

 

[Bbp78]

I usually start at the thermostat. First I replace the battery if it’s got one. Thermostats act weird with a low battery. Mine looks like it is calling for heat, but it doesn’t close the contacts. Others just stop calling for heat. Then I check the wiring to it, because I’ve seen loose wires, and on a new install that’s quite possible. Then I jump to force a call for heat. If it fires from there, the wiring to the unit is fine, and I figure out what is wrong with the tstat. If it doesn’t, go jump at the unit.

Thank you dscheidt! I’m hoping to get some time today after work to try this, I appreciate it. I will keep you all posted.

 

[Bbp78]

Great news, I got a new different thermostat and the heater fired right up, it’s a Christmas miracle! I’m returning the other one since it’s brand new. Thank you all for your help, it’s appreciated. Have a good New Year!

 

[fitter30]

When a contact is closed like R to W voltage is zero or very little
Not calling 24 vac. Check at the thermostat connections.