Troubleshoot a Modine Hot Dawg Heater

Modine Hot Dawg Heater

Troubleshooting your Modine Hot Dawg heater is pretty straight forward. Most problems are solved with a few simple questions.

Troubleshooting Modine Hot Dawg heaters is pretty straight forward. Most problems are solved with a few simple questions.

This time of year many, many people are in the market for a heater. We sell tons of them. Specifically, we sell many Modine Hot Dawg style heaters and also sell a large selection of other Modine heaters. For the most part, we never have a problem with them since they are excellent heaters, and everybody is happy.

There are times though, when a problem arises. We (being super awesome and all) attempt to troubleshoot the problem with our customers. We even have a guy, Charley, dedicated to it. So, it usually turns out well for everyone. Sometimes we get folks calling to ask about a heater we did not sell them or that is old or out of warranty. We help with these too, although we are less able to help in these cases than with a Modine Hot Dawg heater that we sold and is under warranty.

To help out in the event you ever run into a problem with your Modine Hot Dawg, we’ve put together this list to help you troubleshoot on your own. This list covers the large majority of issues that you might encounter with your Modine Hot Dawg Heater, both natural gas and propane. First, some housekeeping:

  1. Warranty – The warranty on a Modine Hot Dawg is always only going to cover parts; not labor. This is pretty typical for a warranty of any kind. In most cases you will also need to purchase the warranty parts, and upon verification that the defective parts are a warranty issue, the manufacturer will issue a credit.
  2. Installation – The first thing we (or anyone for that matter) are going to ask is whether or not you had a certified professional install the heater. If you did, then many times it’s best to just contact that person or company because they will be better equipped to troubleshoot the heater (and you won’t have to deal with any of the hassle). That way, in the event the problem has something to do with the heater being installed incorrectly (as opposed to mechanical malfunction) it usually won’t cost anything to fix.

The Rundown on Your Modine Hot Dawg Heater

If you installed your own Modine heater then it is your responsibility to handle all the details in getting your Modine Hot Dawg heater up and running, which may or may not be an inconvenience to you depending on the situation.

  1. What is the problem – For the most part, the problem is the same every time; the heater won’t fire. As you might guess, there can be many different things causing that problem. Here is a list of questions we ask to get to the bottom of it:
    1. Does the heater turn on? – Once the Modine Hot Dawg heater is hooked up and wired, the best way to tell if it is on is to check the power vent fan. If it’s on then the unit has power and is operating electrically.
    2. Are the electrical and thermostat wired correctly? – If the unit is wired up and should be on but is not, then there may be a problem with the wiring or thermostat. Make sure the wires are connected correctly. Also, it’s silly but it happens a lot, make sure the thermostat is set correctly.
    3. What is the gas line pressure? – If the unit wired, the fan is spinning, and the igniter clicking but there is no ignition, then gas pressure is the first place to check. A Modine Hot Dawg heater will not function unless the line pressure for the specific fuel is within a certain range. Keep in mind that you are almost always going to need a professional with the proper tools to do this for you. The line pressure settings are as follows:
      • Natural Gas: 6-8 WC
      • Propane: 12-14 WC
  2. Is the switch on the gas valve on the interior of the unit switched to the “On” position? – If the line pressure checks out, it is possible that the switch on the gas valve on the interior of the unit is set to the “OFF” position. It should ship from the factory in the “ON” position, but it does happen that some will get turned off somewhere along the line. Make sure yours is on, keeping in mind you will have to remove the side access panel to check this.
  3. Electrical and thermostat are wired and set correctly, fan is spinning, igniter is clicking, gas pressure is good, switch is on…and my heater still won’t work. – Even if everything checks out, there still can be problems. Luckily there is a way to find out what the problem is. With the access panel removed, you should be able to clearly see the control board that is the brains of your Modine Hot Dawg Heater. On that board is an LED light. If the unit is operating normally, the LED will be constant green. If there is a problem, it will blink and may be a different color. The blinking and colors are error codes which you can look up either in the manual, or on a sticker located near the control board on the inside of the heater. Keep in mind that the error codes will be different based on the manufacturer of the board in your heater, and to diagnose correctly you need to know which board you are dealing with.

These steps should have brought you to some kind of conclusion as to the problem with your Modine Hot Dawg heater. If  none of this worked for you, try looking in Modine’s own Troubleshooting Guide. If you are still having a problem, feel free to call us or a certified Modine installation professional for further assistance.


  1. My heater works well, the fan that pushes the heat into my garage has stopped working. I disconnected the fan and hooked it direct to power and it works. so what board or relay is not working. what is the best way to tell which unit is bad. or is there something else wrong?

    Thanks for your time.

    Comment by Gene Atchinson — March 23, 2013 @ 3:46 pm

  2. In order to best assist you there are many questions that would need to be answered. We would suggest the website below that gives you the closest authorized Modine representative in your area that is better equipped to assist you in this matter as well as answer any additional questions you might have.

    Comment by admin — March 25, 2013 @ 11:38 am

  3. I have a hot dawg heater that is not working correctery,
    Vent fan comes on and the igniter glows then the gas valve
    clicks but the gas does not come on, then the blower motor starts and will run for a time then the igniter glows again and the gas valve clicks but does not come on.

    some times it will ignite and work fine but then the next time it will not ignite and will run on and lock out.

    this just started to happen after a new igniter was installed .

    up till the igniter went out it worked fine.

    gas valve is sv9510
    45000 propane
    having trouble finding modle number

    Any help to run down the cause

    Comment by Richard Petroske — April 25, 2013 @ 10:47 am

  4. Since the Hot Dawg heater has multiple components that could be the issue, a Modine specialist would be the ideal candidate to contact and assist you. They will be able to gauge a better sense of your problem and fix the heater accordingly. The previous post has a link to the Modine website that will locate the closest representative in your area.

    Comment by admin — May 1, 2013 @ 2:01 pm

  5. I have 120v coming to the board the green light does not come on replaced board same problem any ideas

    Comment by Rob — October 13, 2013 @ 8:03 am

  6. We suggest contacting the manufacturer to see if they have heard of this issue and what best way to fix the problem. This link will connect you with a specialist at Modine that will be able to assist you further.

    Comment by admin — October 14, 2013 @ 3:29 pm

  7. my heater sometimes starts when only a few degrees of rise is needed and shuts down immediately, and sounds like it doesn’t “cool” down b4 the fan stops

    Comment by Terry Vonasek — December 3, 2013 @ 10:22 am

  8. Is there any way to quiet down the fan, when it first comes on it is very loud then get a little quieter ??? thank you Bill

    Comment by Bill Davis — January 13, 2014 @ 10:15 am

  9. Hi I have a modine hot dawg heater but I am having issues with it. My heater will stop randomly throughout the day and night and not turn back on, but I am not sure why this is happening. My best guess is that it is the cold temperature that causes it to stop working, I am having the most problems with it when it is below zero outside, and have never had a problem with it when it is above 10 degrees outside. I have had it connected up to a computer board but it kicks out when on this control, as well as when it is on a wall thermostat. The only way I can get it restarted is to throw the breaker off and wait a while, then turn it back on, or throw the switch on the back of the heater and wait a while till I turn it back on. I am desperate and need help, not sure how much longer I can keep my greenhouse alive. Thanks for any help you are able to provide me.

    Comment by ian reuter — February 5, 2014 @ 9:02 pm

  10. Our service representative stated that it would be in your best interest to contact a Modine service specialist so that they can assist you with troubleshooting your heater. A specialized Modine rep will be better equipped to locate what particular problems you might be having and assist you with finding a solution.

    Comment by admin — February 17, 2014 @ 9:04 am

  11. It seems all your answers to all the questions are the same.. Call a service tech…
    I have a Hot Dawg Heater that has been working fantastic for over 3 years then it started to malfunction. I turn my thermostat up and the vent fan turns on as it is supposed to. The gas turns on and starts heating as it is supposed to. My problem is the circulating fan on the back of the unit does not turn on to blow the warm air around the garage. I was hoping to fix the problem without having to pay for a tech to come out and charge me a huge bill for something I am capable of doing myself. This should be a easy trouble shoot whether it is some sort of relay or thermostat to the fan or just a bad fan. Any advise other than call a tech would be appreciated.

    Comment by Rob — March 22, 2014 @ 2:42 pm

  12. Our service tech stated that the problem sounds like it is a defective circuit board. He stated that you would most likely have to remove the defective board and replace it.

    Comment by admin — March 24, 2014 @ 2:30 pm

  13. I have a hot dawg heater HD45AH0134 heater comes on flame comes on and everything is running fine then a bout 2 minutes into the heating a clicking noise is hered at it sounds like it is coming from the transformer then the flame goes out and shortly after that the fan behind the unit stops I have had 2 different companies look at this model and all they want to do is to sell me something larger then I really need, the closet modine rep is like 300 miles from where I live so that is out of the question of having a rep sent that far to see me I guess if no one can help me I will just have to purchase a new HD and keep this as a spare parts unit. Out of 10 years never once had a problem with it great company great heater.

    Comment by perry wingerter — August 28, 2014 @ 9:58 pm

  14. found the problem this heater was made in 2002 and they kept making this model till 2006 it had a sophisticated gas valve with a circuit board inside the housing that was what was wrong with it. Circuit board was bad but the cost for a replacement was $300.00 so I ordered a brand new heater made after 2007 that has a run of the mill normal gas valve one that is not so sophisticated or overly priced for such a valve.but thanks anyway.

    Comment by perry wingerter — September 9, 2014 @ 12:11 am

  15. Have a 10 year old Hot Dawg 75000 heater # HD75AH1034 that was purchased from you in 2004 and has worked perfectly up to this point. Being used in a pole barn shop in Michigan.
    The heater burner comes on when calling for heat but cuts out after about 6 seconds of burn
    Replaced the flame sensor blew out the vents and heat exchanger and still the same issue.
    Tries 4 times then goes to lock out mode..
    Any suggestions as to what to look for next?
    Sure appreciate anything you can suggest..

    Comment by Cnewkirk — September 22, 2014 @ 3:32 pm

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