I just had a look at the website and the unit requires a water source with 20lbs minimum pressure to work so you would need a pump without a water source. I don't think I would use this in a trailer either. In a trailer, an electric water heater would be a better choice.
BBQ Team: Lawn Guyland Smokers
Stupidity for Dummies
…because sometimes, you just can’t dumb it down enough…