Modine Hot Dawg heater won't start

[canderson1867]

I have a new ( 3 mos old) heater installed in a greenhouse. It was working fine until two weeks ago when the PE motor would start and then go off after failing to light the burners. I turned off the power and then reset CB. I cylcled it five times and then it started working fine. Last Wed. if failed to even come on. PE moter would not even run. I checked the ignition board and the 3 amp fuse was good. The LED was steady green and the flame LED was orange. The code said it was normal asking for heat request. I replaced the thermostat and nothing changed. I checked the transformer and it is putting out 24 vac. I checked the thermostat out put terminal on the control board and it was 24vac and input was zero , turned the thermostat above room temp, heard it click, and rechecked and input was 24 vac. Still no PE motor action. Checked the voltage to the PE motor and it was zero. Checked the ohms on the motor and meter read indicated closed curcuit. Any more ideas? I am suspecting a bad ignition control board, but would like to check anything else before spending the money.

[Snapperhead]

3 months old ? I'd have it sitting on the desk of whoever i purchased it from ....

[brettrobbins]

These are apparently bad units, I take care of a greenhouse with about 30 of these units barely a year old and I have had to replace multiple circuit boards and fan motors already. Both boards I changed out had bad relays for the IDM motor.

[Snapperhead]

Thats sad , Hell the old fashioned modines hanging from ceilings all around town run for friggin ever.

What have they done to the indestructible Modine ????

[canderson1867]

I ordered it from "Greenhouse Megastore" in IL. I could return it but the effort of pulling all the plants out and dropping it from the overhead mount would be a lot of work. The board runs about $$$. I will check the motor by jumping some power to it. If it runs, then I will probably order the board. Thanks for the info.


Pricing isn't allowed

[canderson1867]

That is what I thought when I ordered it. I had always heard good reports on their heaters. Thanks for responding.

[canderson1867]

Has anyone checked circuit boards replaced to see why they failed? One of the blogs I read where he found a broken weld. He repaired it and it worked fine. With all of these boards coming from the same company, could there be a problem with their robotic welding system? I am going to pull the board and give it a close look before ordering a new one. Will let everyone know if I find anything.

[canderson1867]

Jumped power to PE moter and it ran fine. Going to pull out board and replace.

[coolwhip]

Green houses get very humid...circuit boards don't like so much humidity.

[canderson1867]

Humid is putting it mildly. The board was dry, but you are probably correct. Thanks for the idea. They make a water proofing varnish that I could spray the board with and liquid electrical tape for all connections. Just have to make sure and not cover anything that has to disparate heat.

[coolwhip]

Dont recommend that, it may prove to be an insulator and cause bits to heat up.

[firecontrol]

It's just not the humidity, there are plenty of other things in the air in a greenhouse when combined with the humidity that tend to be corrosive. Modine makes units specifically recommended for greenhouses. Just because a supplier sells something for a specific application doesn't mean that the manufacturer recommends it for that application.

[firecontrol]

. double post

[canderson1867]

Once again correct. All of the components on board are designed to self cool (ceramic resistors ect.). The underside of the board, where all the contacts are very close together and condensation drops are most likely to occur, has very little to do with heat release. I am thinking ( very dangerous for me) that I might be able to coat it with something to protect from all of the corrosion. Any ideas?

[Freightshaker]

I have never coated a board and I agree it could insulate. I believe CRC softseal will do that. I have never used it in that application. Was the old board showing any signs of moisture issues. It could have just taken a random dump. I will attach a picture of a board in aluminum ore in a reznor. It was baried alive and working fine. Sometimes they take abuse sometimes they don't. A lot of times they take a dump for who knows why.

[canderson1867]

I will pull board out tonight. From outside it appears fine with no damage. Thanks for your input.

[canderson1867]

Looks like a component that got a little warm

[Wendo]

I installed one in a greenhouse but I used the closed-combustion model.

[canderson1867]

Just to bring you all up to date on my voyage. I contacted the company where I got the heater and they said the warranty covered the board. I have a new one on the way. Thanks for all of the input.

[canderson1867]

The end of the story. Got the new board and put it in last night. Working great. Temp outside is 48 and inside 64. Thanks to all the pictures I took with my IPad I was able to get all the wires to the correct terminals. Thanks again for all of your support. Have a great day. Curt