Mr Heater big maxx blowing fuses

[Nnorman1]

Just hung my mr heater 80k Btu in my barn and went to test it before I get my propane tank and constantly blows the 3 amp fuse only when you turn the thermostat on, could my circuit board be bad?

 

[D45]

Or wired wrong?

Bypass the tstat with a jumper wire

Does it still pop?

 

[Nnorman1]

Or wired wrong?

Bypass the tstat with a jumper wire

Does it still pop?

 

[Nnorman1]

I think I have it right but could be wrong

 

[Nnorman1]

 

[PoorUB]

Disconnect the wires for the thermostat at the heater and turn on the power, does it still blow the fuse? If no, jumper wire the R terminal to the W terminal at the heater and see what happens. If the heater runs, it is the thermostat wiring or the thermostat. If it blows the fuse you have a bad part in the heater, not sure what.

 

[BillK]

Unless I am looking at the wrong wiring diagram the one I see does not use the green wire ? Can you post a picture of your wiring diagram from your users manual ?

 

[35Ford]

Green would start the fan if the unit is set up for it.

 

[REDSHELBY]

Unhook the B wire its for heat pump.

 

[PoorUB]

Unhook the B wire its for heat pump.

Missed that!! No C connection in the 'stat. Must be a battery only 'stat.

 

[LS6 Tommy]

I think I have it right but could be wrong

X2 on the "B" connection at hthe stat. You also don't need the R-RC jumper...

 

[Nnorman1]

Unhook the B wire its for heat pump.

That fixed it