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.
(Brewmaster and Pitmaster)
BBQ Team: Lawn Guyland Smokers
Brewery: Black Dog Brewery
"Sam I Am": XL Big Green Egg
"R2 and D2": Twin 22" Weber Smokey Mountains
Custom Made Automated Souped Up Sabco