4E Version uses 12VDC to operate Gas and Electric
Both on/off switches use common 12VDC from fused source
Electric switch sends 12VDC to the Circuit Board via WHITE wire
*Circuit Board sends 12VDC to DC Relay that closes allowing 120VAC to heater element
Need 15A 120VAC Circuit Breaker to supply the AC for element
Gas switch send 12VDC to circuit board via ORANGE wire
BLUE wire comes from circuit board to FAULT Light at switches for visual indication of No Flame lighting/proving it lit and/or if ECO opens/lockout controls
Swap out the Single GAS on/off for Dual Gas/Electric Switches
***Can jumper the 12VDC from gas to electric---but need to run separate 12VDC wire from Electric to the WHITE wire
See pgs 24 & 25 for conversion of 3E to 4E
https://manuals.heartlandowners.org/...e%20Manual.pdf
The DC Relay and element are on backside of water heater tank under the protective cover