Our 15 year old mh has an Atwood electric and or propane 10 gal something high recovery water heater. Only real problems we had was last year and replaced both high and low thermostats. The manual has some instructions on cleaning the orafice with a mall diameter wire about the size of the tiny wire used on old tags for equipment. On line, I haven't looked, but there were variosu psots everywhere on cleaning the orafice. The one thing I don't like is the couple of plug together wires that seem to want to corrode. Dialectric compound not grease on them puts a stop to that. The thin and easily broken fusible link in the clear plastic tube, seems to always want to be in a place where it wants to get bent. Not sure if they can be bought but I will if I can and keep in the tool box. Oh and the drain plug. Someone put a nylon or some plastic plug in it, not me, and from tightening a bit much it later decided it was going to leak and when I touched it it broke and got a quick and very hot bath.
Atwood was at the Rally and gave me a tap to clean up the threads..after the evening before neighbors help we, actually mostly them, with pocket knife and etc to get the old plug out inuring the threads a bit. So we carry a number of the intended plastic or whatever plugs. Still need to find an extraction tool for broken plug I read about somewhere.
The control board has been brought up here a number of times of needing to be replaced.Suppose an extra one in the tool box would be a good idea.
No rocket science about the water heater. Facing an unknown problem, with no idea of what might be the problem the first time is the problem.
The manual on everything are a problem in lack of information.
All those seminars on equipment on our Mhs at Rallys...well I need to start attending them.
A lot more would if they served hotdogs or something ...hint hint.