ATF: Cyclone - Furnace Operation

New Cy4520 purchased. Furnace was operating perfect at first. Now there is no warm air blowing from vent. Need help troubleshooting.
 

danemayer

Well-known member
Hi calwes9793,

Congratulations on the new Cyclone and welcome to the Heartland Owners Forum.

The sequence of operation for your furnace is:

- Thermostat senses that ambient temp is lower than the set point
- Thermostat closes
- Relay above air conditioner return closes sending 12V to the furnace
- Furnace blower starts
- Sail switch at blower closes when blower is at 75% of rated airflow, signaling circuit board to open the gas valve
- gas valve opens and electronic ignition fires
- Circuit board looks for signal from flame sensor indicating that ignition was successful.
- Warm air should start coming out the vents. Usually the bathroom vent, closest to the furnace, gets hot pretty quickly.

If your blower is operating, but the air is not getting warm, usually that means that ignition was not successful and after 3 attempts, the furnace stops running and goes into a safety lockout. The thermostat has to be cycled to OFF and back to HEAT to reset.

If your propane supply is low, there may be just enough propane flow to satisfy the flame sensor, but only provide very lukewarm airflow.

Make sure the furnace air return inside the coach, and the exterior air vents at the furnace are not blocked. Also, make sure no floor registers are blocked. That can cause the overtemp sensor to trip, cutting off the gas flow.

If none of that helps, take a look at Gary Brinck's Troubleshooting Guide in this folder.
 

Bob&Patty

Founders of SoCal Chapter
Are you low on propane? I assume your stove works properly. Did you get your propane bottles filled before this happened? Reason I asked, if you turned the bottles on too fast, you could have an air lock in the lines. Best I can tell you.
 
Thanks, I will check when I return to my RV. My girlfriend is relaying info to me and I did research a couple of the troubleshooting steps that you have sent me. Just have to have her check those items.
 

Ladiver

Well-known member
Check the controller and make sure you are on FURN. I know this sounds obvious, but over Thanksgiving, my furnace was not working but I was getting some warm air out of the a/c ducts. There was nothing coming out of the floor vents and I thought I had a problem. I looked at everything and it appeared a problem with the furnace not turning on. Well, it helps to be set to FURN on the controller! Solved my problem. Hopefully your problem is that simple.
 
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