Reznor LP heater not heating...

[Nor'Easter]

In my garage I have a Reznor V3 Tcore heater that runs off of LP. This winter it has started to have some issues.

Upon start up it lights the burner as expected, however when the fan turns on the burner shuts off, and all I get is cold air. The indicator light flashes to acknowledge a call for heat yet it shuts the burner off..

If I restart it 5-10 times eventually it works properly and will do so indefinitely if left on.

I will add that if I get the garage to 40 degrees via woodstove, the heater then starts heating as it should. The thermos lowest heat setting happens to be 40 degrees. ???

 

[nehog]

...
I will add that if I get the garage to 40 degrees via woodstove, the heater then starts heating as it should. The thermos lowest heat setting happens to be 40 degrees. ???

How are you turning it on if the lowest the thermostat can go is 40 and it is below 40? My setup once I hit below 40 my thermostat just 'locks up'. (I have to heat it with my heat gun to get the heat on!)

 

[Nor'Easter]

The heater itself has a shutoff switch, the thermo is in the center of the space. Flip the switch, thermo lights up, displays ambient temp, and temp. to heat to, heater starts running.

 

[dfiler2]

Does the unit have an air proving switch that is being affected when the blower comes on.

 

[Nor'Easter]

I have no idea, I'm pretty dumb when it comes to HVAC. But I sure can restore an old truck nice when the heat comes on.

Can I get a thermo that will go below 40 degrees?

 

[ewang]

I use a Honeywell mechanical line voltage thermostat for low temp operation.
http://www.grainger.com/product/HONEYWELL-Line-Volt-Mechanical-Tstat-2E834

 

[JCByrd24]

My Modine suffered from a similar problem where it would only run a few minutes and shut down. It was the upper flame roll out detector. I believe an LED diagnostic pointed me to that and then I was able to jumper it to confirm. Found online that a guy had a similar problem where his top burner was not crimped enough at the top and flame was actually coming out between the plates there in addition to the round hole where it is suppose to. This is very close to the flame roll out switch so tripped it. He and crimped this seam tighter and solved is problems, and this fixed my problem as well. When you have flame verify that the flame is not creeping up the seam.

 

[Nor'Easter]

My Modine suffered from a similar problem where it would only run a few minutes and shut down. It was the upper flame roll out detector. I believe an LED diagnostic pointed me to that and then I was able to jumper it to confirm. Found online that a guy had a similar problem where his top burner was not crimped enough at the top and flame was actually coming out between the plates there in addition to the round hole where it is suppose to. This is very close to the flame roll out switch so tripped it. He and crimped this seam tighter and solved is problems, and this fixed my problem as well. When you have flame verify that the flame is not creeping up the seam.

The burner lights for maybe 2 seconds and then the fuel is shut off, I can hear the click of the valve, or whatever stops the flow of gas. Not sure what would be telling the machine to stop fueling.

 

[Will S.]

Do you have an installation/troubleshooting manual for that furnace? If not, it may be downloadable.

It sounds to me like there may be a defective flame sensor, not detecting flame, therefore shutting off fuel. Are there any error code lights flashing on the main board, following shutdown?

 

[CNGsaves]

What is temperature range of the thermostat??

Likely your garage is colder than T-stat designed to operate.

 

[JCByrd24]

If it's happening in 2 seconds I concur with a flame detector as well. Mine would run a couple minutes at least.