Section 8
Portable propane tankless water heaters: input, flow and maximum rise
This table lists burner input, maximum flow and the highest possible temperature rise for 5 Eccotemp portable propane heaters. Eccotemp lists a burner input and a maximum flow for each model and no temperature rise. The maximum rise is calculated from the burner input.
| Model | Input | Maximum flow | Maximum rise at maximum flow | Maximum rise at 1.0 GPM | Rated rise |
|---|---|---|---|---|---|
| L5 portable | 37,500 BTU/h | 1.5 GPM | 50 F | 75 F | Not listed |
| Luxe EL5 portable | 37,500 BTU/h | 1.5 GPM | 50 F | 75 F | Not listed |
| Luxe EL7 portable | 52,500 BTU/h | 1.85 GPM | 57 F | 105 F | Not listed |
| L10 portable | 75,000 BTU/h | 3 GPM | 50 F | 150 F | Not listed |
| Luxe EL10 portable | 75,000 BTU/h | 3 GPM | 50 F | 150 F | Not listed |
Sources: inputs and flows come from Eccotemp's product pages[1][2][3][4][5]. A heater loses part of its heat up the flue, so the actual rise is lower than the maximum.
Portable propane heaters run from a 20 lb cylinder and a garden hose and are common for outdoor cabin showers. With no rated rise, a flow at a given rise cannot be listed. The burner input does set an upper limit. With all of the burner's heat going into the water, the rise equals the input divided by 500 times the flow.
8.2 Maximum rise by model
At its full 1.5 GPM, the L5 cannot raise water more than 50 F. With 52 F well water, that is an outlet of 102 F at most, before losses. A lower flow gives a hotter outlet. At 1.0 GPM the maximum rise is 75 F. The L10 and Luxe EL10 have twice the input and twice the flow, so their maximum rise at full flow is the same 50 F.
8.3 Placement
These are outdoor, portable units. Eccotemp's L5 page says the built-in rain cap is "not recommended for permanent outdoor installation"[1]. Use and placement limits are in each unit's manual, and the manual governs.