Modine hot dawg

[WayneBG]

Need some help lol.
our new how has had lots of expensive issues that we’re trying to work through. Our garage heater is a hot dawg, when we turned on the power fan came on but no spark. We asked our heating guy to take a look, he said it was the board. At our expense we’ve since found out he’s the kinda guy the just keeps replacing parts until he hits the right one. He quoted $425 for the board plus his time.…
decided to take a look myself. Voltage seems good, pressure switch seems good, roll out switches haven’t tripped and seem good, igniter looks good as does flame sensor. Disconnected everything that I could, cleaned and made sure good connections. Turned on the power and it fired up, ran for maybe 25 minutes and went off flashing code 4. Wouldn’t fire up again, tried the next day and fired up and went through the same process again, this went on for a week with varying run time of 5 to 25 minutes. Now all I’m getting is when it turns on the main blower comes on and no spark, it cycles but misses the spark and flashing code 4, every now and then the other green light also flashes.
small town in the prairies, not a lot of options for service techs. Anyone got any suggestion? TIA

 

[The Cobbler]

is there a label on the side of the unit that says what the various flash codes are ?

 

[WayneBG]

is there a label on the side of the unit that says what the various flash codes are ?

Says that the limit switch is open, but it isn’t. I’ve kept a continuity meter across terminals.

 

[PoorUB]

If you are this capable skip the HVAC tech and order online. That board is probably $100.

Make certain all the wiring is good, confirm the limit switch is good, then probably toss a board in it.

 

[WayneBG]

If you are this capable skip the HVAC tech and order online. That board is probably $100.

Make certain all the wiring is good, confirm the limit switch is good, then probably toss a board in it.

A company in Calgary AB. Quoted $500 cad and the local guy said $425. I’ve seen it in the States @ $130 us but none seem to ship to Canada especially without a gas license.…..Canadian prices are nuts for most things lol

 

[PoorUB]

A company in Calgary AB. Quoted $500 cad and the local guy said $425. I’ve seen it in the States @ $130 us but none seem to ship to Canada especially without a gas license.…..Canadian prices are nuts for most things lol

Do you know anyone state side that could ship it to you?

 

[D45]

https://www.google.com/url?sa=t&source=web&rct=j&url=https://irp-cdn.multiscreensite.com/46737ca5/files/uploaded/Hot%2520Dawg%2520Troubleshooting%2520Guide.pdf&ved=2ahUKEwiC-KHv4fD8AhVHomoFHfN5DboQFnoECBQQAQ&usg=AOvVaw0n2T9rTzPqWZ1IXnMm5zt2

 

[WayneBG]

https://www.google.com/url?sa=t&source=web&rct=j&url=https://irp-cdn.multiscreensite.com/46737ca5/files/uploaded/Hot%2520Dawg%2520Troubleshooting%2520Guide.pdf&ved=2ahUKEwiC-KHv4fD8AhVHomoFHfN5DboQFnoECBQQAQ&usg=AOvVaw0n2T9rTzPqWZ1IXnMm5zt2

Thanks, #6 on the matrix is all good, the fan won’t shut off and voltage is good. #7 is one I can’t check as I don’t have a pressure tester for the gas.
I’ve been reading all the modine manuals, despite the the code 4 nothing matches. When the other green led flashes the error code goes away for a minute or so. The modine manuals don’t resolve the issue.

 

[WayneBG]

Do you know anyone state side that could ship it to you?

Unfortunately no. Last trip to Fargo was 2018 when kids and grandkids were in a rta and grandson was hospitalized……heck of a trip lol

 

[Certified Drunk]

try all the wire connections, mine had a pin pushed out.

 

[WayneBG]

try all the wire connections, mine had a pin pushed out.

That’s possible thanks ….. I’ll check that one tomorrow

 

[PoorUB]

Unfortunately no. Last trip to Fargo was 2018 when kids and grandkids were in a rta and grandson was hospitalized……heck of a trip lol

I can get the part wholesale, but no returns!

 

[WayneBG]

I can get the part wholesale, but no returns!

Do you know the cost? You can email me if it’s easier
[email protected]

 

[American Locomotive]

Are you sure there is only one limit switch?

 

[PoorUB]

Do you know the cost? You can email me if it’s easier
[email protected]

Do you have the part number? No clue which model you have.

We can take this to PM here i=on the group.

 

[MOS3522]

https://irp-cdn.multiscreensite.com/46737ca5/files/uploaded/Hot%20Dawg%20Troubleshooting%20Guide.pdf

 

[AldeanFan]

https://www.princessauto.com/en/control-board-60105/product/PA0008103442

I wonder if this one would work?

 

[WayneBG]

Are you sure there is only one limit switch?

No, it has 2 roll out switches and a limit switch….as far as I know

 

[WayneBG]

Are you sure there is only one limit switch?

No, it has 2 roll out switches

Do you have the part number? No clue which model you have.

We can take this to PM here i=on the group.

I believe the part number of the board is 5H79749 I’ll double check this evening but sure it is

 

[WayneBG]

https://www.princessauto.com/en/control-board-60105/product/PA0008103442

I wonder if this one would work?

looks like a different set up, but thank you

 

[jlrut]

The only way to monitor that limit is to use your meter set to voltage, measure across the terminals of the limit switch while the unit is operating. If the switch opens you’ll see 24 volts on your meter, otherwise 0 volts means the switch is closed. Not likely that the control board failed and still throws an open limit code after running for 25 minutes. I’d wager on an over fired gas valve, improperly installed lp conversion maybe, or slow running fan.

 

[WayneBG]

The only way to monitor that limit is to use your meter set to voltage, measure across the terminals of the limit switch while the unit is operating. If the switch opens you’ll see 24 volts on your meter, otherwise 0 volts means the switch is closed. Not likely that the control board failed and still throws an open limit code after running for 25 minutes. I’d wager on an over fired gas valve, improperly installed lp conversion maybe, or slow running fan.

Ok thanks. I’ve only been measuring continuity across the terminals, didn’t realize I needed to check for voltage. Running on natural gas, fan speed appears to be good.

 

[Gear Box]

I would check the wall thermostat also for any loose or failing/broken wires
Good luck

 

[WayneBG]

I would check the wall thermostat also for any loose or failing/broken wires
Good luck

Thanks. I didn’t mention but I replaced thermostat and had a jumper across terminals on the board. Sorry should have said