Iím not fluent on your 86 camper and maybe someone who has an older once can better guide you on the HW heater, but in case they canít there is one way to figure out if there if a ďswitch ď is somewhere.
First is to undo the outside cover on the HW heater. See if you can find a brand name and model number. I can try and look it up to find out what you have.
Also look to see if there are any wires in there. The age of your might be a total gas unit. And if it is then the gas control and pilot lighting would all be done outside. There would be a gas lighting instructions sticker on the cover unless it fell off. And the older all gas systems had a knob on the gas valve that you push down and hold to light the pilot, then once the pilot lit, you can release the knob and turn the gas on and the heater just starts working. It is all gas pressure controlled, no elastic control.
If you see wires going to devices on the heater, well then you have a form of electric control of the system and switch will be somewhere.
If now one else comes along that knows, give us a make and model and even better a picture of it and we can help you back into what to look for.
Hope this helps
PS What model camper is it?
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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