Yes, the 2006 models had gas/electric water heaters. But, a burnt out element is extremely unlikely to "fault" 1120V hot to the frame - instead, it will simply not conduct electricity at all. The 'electric' power switch, being off, should also assure that it doesn't draw anything.
Instead: It's a simple fact that many Converters (definitely INCLUDING the "miserable" 2006 WFCO in the 2619, as well as the preceding Magnetek model))
do not present level and balanced current loads on the "hot" and "neutral" sides of the 120V input while generating significant amounts of 12V power. (Either to run the Fridge in 12V electric mode, or to charge the batteries.)
Under load, the transformer is being switched by control electronics, to handle the switch (on the "hot" circuit) between positive and negative portions of the waveform. (BTW, in WFCO, this creates a 60-cycle "humming" noise, separate from the fan noise. The WFCO converter is only 2-phase.) In addition to the audible hum, that switching creates ripple on the 120V circuits ("hot" and current-carrying "neutral"). And the cheap electronic control circuits create additional ripple on the input/output 120VAC source wires. These "ripple" characteristics are
not balanced in time, you can see considerable voltage differences between "hot" and "current carrying neutral" on a dual trace oscilliscope (if you can get your hands on one).
The unbalanced "Ripple" is too big for most modern, sensitive GFIs to accept without creating a fault. Campground wiring is NEVER built with GCI on the 30A or 50A circuits. If you want to plug-in the WFCO at home, then you must probably create a new dedicated circuit: And you should create it as a 30A or 50A dedicated circuit, because modern NEC requires arc-fault GFIs on all of the 15A/20A circuits. (Your Local Codes might not require arc-fault yet, but they're definitely going to require GFCI.) An exception is provided for point-to-point high-amperage circuits.
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WFCO can be used as an AC distribution unit on a GFI circuit (running the Air Conditioner, or the Water Heater, or the Fridge in 120VAC mode). But if you try to use it
as a converter for charging batteries or running the Fridge in DC mode, it will blow the GFI. (But there's no sense in running fridge with 'DC mode' when you have AC available, and the WFCO is not a very good battery charger - it typically falls into "Float" mode when the battery is only 70-75% full.)
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Your best options for charging the battery at home are: (1) Put in a new circuit; or (2) Use a completely separate and BETTER battery charge device, such as this one:
https://www.amazon.com/CTEK-56-864-A.../dp/B006G14FK8 I've got one, and it does a great job.
If you buy the CTEK (and even if you don't) you'll want to replace the cylindrical "Battery Fuse" (which runs all the TM 12V battery loads through a tiny-rust-prone spring) with this convenient and problem free circuit breaker:
http://www.ebay.com/itm/12V-DC-30A-C...P/291808183404. You need this because the CTEK only delivers about 4A current (2A per battery), and can't do effective charging and battery maintenance while TM "phantom loads" consume more than a third of that total. Using this circuit breaker as a "battery disconnect" eliminates the phantom loads. (With some side effects, such as losing stereo system "memorized stations" and presets.) It needs a full day or two to charge discharged batteries, but it does a fantastic job as a "maintainer".