RV water heaters: recovery, flow and anode requirements
Choose an RV water heater from the actual model’s recovery or flow performance, available fuel and electricity, and maintenance requirements. Storage capacity and recovery both matter. Tankless heating still needs enough water, fuel, power and permitted flow; it does not guarantee an uninterrupted shower in every condition.
Use a product’s recovery figure rather than a universal time
Suburban’s 2025 catalog lists SW6DE as a six-gallon model with 12,000-BTU/h gas input and a 1440-W electric element. Its stated recovery figures include 6 GPH electric-only and 16.2 GPH gas plus electric.
| Calculation | Conditional comparison |
|---|---|
| 6 gal÷6 GPH | One hour of nominal volume recovery |
| 6 gal÷16.2 GPH | About 22.2 minutes of nominal volume recovery |
| 1440 W÷120 V | 12 A for an assumed resistive element at nominal voltage |
The arithmetic compares rated volume and rate; it is not a tested cold-start stopwatch result. Inlet temperature, setpoint, mixing and concurrent draws affect a shower. Do not transfer these figures to another tank or call every electric heater a 1400-W load.
Tankless operation has a minimum flow
Truma’s AquaGo comfort description says the burner starts when flow exceeds about 0.4 US gal/min. That is an activation condition, not a promise that any hot-water demand can be supplied at every inlet temperature.
A fixture reducing flow below a heater’s operating requirement can interrupt heating. Check the exact heater and fixture instructions rather than assuming the burner or propane regulator has failed. Available fresh water and waste capacity remain limits during an off-grid shower.
Anode requirements follow the product, not a metal slogan
Suburban’s FAQ recommends replacing the applicable anode annually or when consumption or weight loss exceeds 75%. Verify the exact heater and rod before ordering. Do not add an anode to an appliance whose instructions do not specify one.
Allow hot equipment to cool and depressurize as directed before permitted service. Never plug a relief valve to stop a drip. Repeated discharge, scalding or a damaged fitting requires diagnosis; there is no universal harmless-drip rule.
Winter bypass and draining are model-specific tasks
Truma’s AquaGo winterizing instructions require draining the appliance through its prescribed procedure. A coach bypass position alone does not prove an internal heater or other appliance has emptied. Use the exact sequence for every connected component.
Confirm a storage-tank heater is full before energizing its element. An approved inverter could supply an electric heater off-grid if the entire system supports it; shore power is not its only physically possible source. Use the actual load budget and no-hot-water diagnosis before changing equipment.