That diagram is showing wiring for gas or electric with one switch.....
What is missing is that 2 switches are needed. One for each heating source.
Can you tie both to 1 single switch. Never tried it. Not a normal/standard configuration
Both electric/gas would operate ALL the time/at same time.
No individual heating option.
IF 'Fault' occurs don't know if both sources would trip or just one with issue ?
(Individual switches.......only the one with issue would trip on fault. Fault reset by turning On/OFF switch off then back on--after issue repaired that caused fault)
