I have a 2021 Cyclone 4005, The water heater (Atwood) used to work correctly then the Electric started chattering on the contacts so I turned it off electric and went to Propane, no issues. Then when running on Propane it would reach its set point and turn off and then about every minute it would reignite and run for about 30 seconds then shut back off again so I had no choice but to shut it off from the controller. I called Heartland and they sent me new E.C.O. and Tstat for it. I replaced both of them and made sure it was wired exactly the same way it was before I replaced them. Now when I turn on the "Electric" water heater the "Propane" kicks in. If I turn that off and turn on the Propane water heater then nothing happens. I would really like to only use the Electric to save propane if anybody has any ideas I'm all ears. Also when running in the Propane mode it does reach the setpoint and shut off like its supposed to and doesn't turn back on for a while so the short cycling has been corrected.