RV Water Heaters

Replacing or servicing an RV water heater

A full water heater swap is one of the more doable RV projects, but only if the new unit fits the hole the old one left. Suburban and Atwood/Dometic heaters use different tank materials, door flanges, and mounting cutouts, so start with what your rig already has rather than what's on sale.

• Tank size and brand. Six gallons is the common size, with 4- and 10-gallon units out there. When you replace, match the gallon capacity and the mounting cutout — a Suburban won't drop cleanly into a Dometic opening without modifying the sidewall.
• Fuel and ignition. Decide between gas-only and gas/electric combo, and how it lights — pilot-style, DSI (direct spark), or electronic ignition. A combo model's electric side is handy on shore power, but the gas side still does the heavy lifting when you're dry camping.
• Bypass kits. A bypass valve routes RV antifreeze around the tank at winterizing so you don't waste six gallons of pink stuff filling it. The Valterra, Camco, and B&B kits here mount at the tank; a three-valve setup gives the cleanest bypass.
• Access doors and bug screens. A cracked access door lets weather into the compartment, and an open burner vent is an invitation for wasps and spiders — whose nests are a top cause of a gas heater that won't stay lit. A stainless bug screen keeps the tube clear.

Whatever you're doing to the tank, it's the right time to service the parts inside it: pull and check the anode rod and inspect the element and thermostat while access is easy. If you're winterizing, coordinate the bypass with the rest of your fresh water system.