The stock Dometic furnace in our 2020 Hawk is acting up. It throws a code that points to the limit switch.
Before I go further, I’ll indulge in a small rant:
When troubleshooting, people often blame the electronics for not working properly, when they really need to take a step back and start with the basics. As a lift mechanic at our local ski area, I can’t tell you how many times a $20,000 PLC was blamed, when a simple loose connection was the culprit.
Bill Hewitt at powerstrokehelp.com has a great rant about this sort of thing from a mechanical perspective. Search “loss of power 7 3l powerstroke“ on YouTube. Very entertaining.
There, that wasn’t too bad, was it?
So after blaming the electronics, bypassing the heat exchanger limit switch, and still not getting anywhere, I READ THE MANUAL, which told me to clean the blower once a year.
Huh.
I also remembered to check every component in the circuit. In this case, the limit switch and fly switch are in series.
So after remembering the basics, I found:
The fly switch was all jammed up with lint.
The blower was dusty.
The heat exchanger outlet was a bit plugged, because I cleaned the grille and didn’t put it all back together well enough.
So, I:
Cleaned the fly switch.
Blew out the blower with compressed air.
Straightened out the flexible ducting so the blower doesn’t load up.
Shortened the thermostat cycle time to the minimum.
At this point I’ve gotten a pretty good understanding of how the thing works. We’re currently testing it in a Laramie WY parking lot, and I’m cautiously optimistic.
I talked to a guy at an anonymous RV sales/service store who gave me a few hacks:
Remove the ducting and grille to improve airflow.
Bypass the limit switch.
Has anyone here used these hacks to improve performance in cold conditions?
Does anyone have other ideas?
Thanks
Before I go further, I’ll indulge in a small rant:
When troubleshooting, people often blame the electronics for not working properly, when they really need to take a step back and start with the basics. As a lift mechanic at our local ski area, I can’t tell you how many times a $20,000 PLC was blamed, when a simple loose connection was the culprit.
Bill Hewitt at powerstrokehelp.com has a great rant about this sort of thing from a mechanical perspective. Search “loss of power 7 3l powerstroke“ on YouTube. Very entertaining.
There, that wasn’t too bad, was it?
So after blaming the electronics, bypassing the heat exchanger limit switch, and still not getting anywhere, I READ THE MANUAL, which told me to clean the blower once a year.
Huh.
I also remembered to check every component in the circuit. In this case, the limit switch and fly switch are in series.
So after remembering the basics, I found:
The fly switch was all jammed up with lint.
The blower was dusty.
The heat exchanger outlet was a bit plugged, because I cleaned the grille and didn’t put it all back together well enough.
So, I:
Cleaned the fly switch.
Blew out the blower with compressed air.
Straightened out the flexible ducting so the blower doesn’t load up.
Shortened the thermostat cycle time to the minimum.
At this point I’ve gotten a pretty good understanding of how the thing works. We’re currently testing it in a Laramie WY parking lot, and I’m cautiously optimistic.
I talked to a guy at an anonymous RV sales/service store who gave me a few hacks:
Remove the ducting and grille to improve airflow.
Bypass the limit switch.
Has anyone here used these hacks to improve performance in cold conditions?
Does anyone have other ideas?
Thanks