Here are a couple more pictures. While you RV is different than ours, they are all basically the same.
This picture shows the outside cover removed. The yellow arrow is pointing to the electric on/off switch that is behind the outside cover. Some RVs have this electric switch PLUS another HWH electric on off switch inside the camper at the control panel somewhere.
This picture shows the HWH from inside the camper. There may be a wood panel that needs to be removed to see the backside of the HWH. The yellow arrow is pointing to the HWH bypass valve.
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2011 Avalanche 340TG
2001 Silverado 2500HD Crew Cab
B&W Companion Fifth Wheel Hitch
Had
2008 Hornet Retreat 38BHDS (Good camper)
2006 Terry 320DBHS (POS)