The ECO and the thermostat behind the black sticy foam are common for Gas or Electric operation and operate through the control board. You can rule them out if the heater operates on propane. Could very well be the electric element burnt out if it was not totally submersed or accidentally turned on over the Winter.
Thanks Bob...We bought the TT used and the Heater never worked on gas...We didn't mind because it's on a permanent setting...Now i'm kicking myself for not fixing it...
Fred & Jodie, dogs, Zoey & Mika
2010 F150 5.4, 3.55, 4x4, Equli-z-er Hitch
2007 Forest River Salem 27RB LE
2009 Nomad 3980
just an update...I have contunity (sp) between element, ECO, Stat, and fusable link...Tested and have power from the hot side of the circuit breaker...I did replace the plotted circuit board and at least the gas works now, but still not on A/C