For RV showers, the Symmons Temptrol and Phoenix PF213200 are top mechanical thermostatic mixing valves. Digital models like the Kohler DTV+ require significant electrical modifications that aren't practical for most RV installations.
Yes, you need a DC-DC charger to safely charge your lithium battery from your truck's alternator. Installing one between your truck's charge line and battery will prevent alternator damage and provide optimal lithium charging.
RV PEX connections use crimp rings, not compression fittings. For DIY repair, PEX cinch clamps with ratchet tool are easiest. SharkBite push fittings are tool-free but cost more. FIP refers to threaded connections at valves and fixtures.
You can remove a Dometic 10-gallon water heater from behind the refrigerator by creating temporary access through the exterior compartment or carefully maneuvering connections from the front. Most cases don't require refrigerator removal with proper technique.