Hot Dawg 45,000 BTU cold start problem

[greenthumb]

Hi. I installed a Hot Dawg 45,000 BTU unit in my garage in September. The unit is connected to a natural gas line, and is kept powered off when not in use. When powered on, the unit will try five times to ignite, and then go into failed ignition lockout. Flipping the emergency power switch off and then on again cuts power to the unit and clears the lockout for another try. Sometimes it's necessary to repeat this process several times to get ignition. The colder the weather is, the worse the problem seems to be. The unit did not behave this way until recently, but prior to this temperatures were higher, which may have concealed the problem. The unit runs fine once it finally ignites and gets hot, cycling on and off as needed to maintain a comfortable temperature. Any ideas about what might be causing this? Thanks!

 

[D45]

Proper gas pressure/gas line size supplied to the unit?

Valves for the supply line all turned on? (I have two valves)

Fault codes blinking?

 

[spudley]

With 120V applied, normal operation is a single LED flash every few seconds on the control board. After lockout, count the number of flashes on that LED and refer to the manual or sticker inside cabinet (if equipped) to identify fault.

Is this a new or used heater and (if used) have you set gas pressure on the valve?

 

[wanderer]

Most common cause is a dirty flame sensor. Overtime they get a slight amount of buildup on them and they become slower to respond to temperature, The heater thinks that the flame is not kept on so it shut it off to be safe. They can typically be cleaned with a little bit of steel wool and reinstalled.

That it, you should have a blinking LED inside the cover. What’s it say?

 

[greenthumb]

All valves are open as they should be. After it fails to ignite I get 4 flashes on the control board LED indicating "in lockout from failed ignitions or flame losses." If I flip the power off/on to reset the unit and keep trying, it will eventually light and then runs fine. Like I said, it happens when it's colder. It's almost 50 here today and it starts up immediately without a problem.

 

[greenthumb]

Brand new. After it fails to ignite I get 4 flashes on the control board LED indicating "in lockout from failed ignitions or flame losses." If I flip the power off/on to reset the unit and keep trying, it will eventually light and then runs fine. Like I said, it happens when it's colder. It's almost 50 here today and it starts up immediately without a problem.

 

[greenthumb]

Most common cause is a dirty flame sensor. Overtime they get a slight amount of buildup on them and they become slower to respond to temperature, The heater thinks that the flame is not kept on so it shut it off to be safe. They can typically be cleaned with a little bit of steel wool and reinstalled.

That it, you should have a blinking LED inside the cover. What’s it say?

Dirty flame sensor. Curious . . . wouldn't that be a constant problem rather than just at cold startup?

 

[Chevy-SS]

Here's your best bet. Look at the Guide to become familiar with the unit, then if no luck, call the "Live Operators".......

Modine Troubleshooting Guide:
https://www.modinehvac.com/wp-content/uploads/2020/01/HD_Troubleshooting_Guide_6-586-1.pdf

Modine Live Operators: 800-828-4328

If you call them (or figure out the issue), please post feedback... I have exact same heater, as probably many here do.

 

[wanderer]

Dirty flame sensor. Curious . . . wouldn't that be a constant problem rather than just at cold startup?

When you’re starting from the colder temperature you’ve got to heat it longer before it will signal the gas valve. This is your problem. just clean the thing and reinstall and your problem will go away.

 

[RealtorChip]

When you’re starting from the colder temperature you’ve got to heat it longer before it will signal the gas valve. This is your problem. just clean the thing and reinstall and your problem will go away.

Is the flame sensor the red spark plug looking connector that has a metal rod that runs in the lower burner? SO if I pull the plug off and unscrew the 2 screws that hold the rod in and pull it out and sandpaper it this should make my 75K Btu H Dawg run again. I have a 4 flash fault. Thanks. My biggest issue is trying to get my head in to see what I'm doing. Thanks for the help!!