Eccotemp 45HI
Amazon customer rating as of
Tankless Geek editorial score: 4/5
The Eccotemp 45HI is the higher-capacity unit in Eccotemp's indoor line: a non-condensing propane tankless with a modulating 19,000–150,000 BTU/h burner and up to 6.8 GPM, aimed at whole-home use at a budget price. Its useful trick is 0.7 GPM low-flow ignition — it fires on small draws where cheaper units won't — and it adds a digital display, anti-freeze protection, and CSA approval. Note it needs a 120V outlet to run its exhaust fan and controls, and it's certified for use up to 2,000 feet elevation.
At 6.8 GPM it can supply two to three fixtures in warm climates, tapering to one or two in the cold. Being non-condensing (~0.80 UEF), it costs less up front and skips the condensate drain, but uses more gas per gallon than a condensing unit and needs proper venting. Its roughly 3.8-star owner rating reflects a familiar budget-tankless pattern: strong value and fast hot water when everything's dialed in, with a minority reporting setup fussiness or reliability issues. Backed by a solid 10-year heat-exchanger warranty, it's a reasonable value pick for a whole small home.
Key Features
Best Use Cases
Our Verdict
A budget whole-home indoor propane unit with genuinely useful low-flow ignition and a strong 10-year heat-exchanger warranty. Good value for a small-to-mid home in warm/mild climates that can supply a 120V outlet and proper venting. Temper expectations on reliability given the mixed owner rating, and remember the 2,000-foot elevation limit.
Technical Specifications
| Input | 19,000–150,000 BTU/h (propane, modulating) |
|---|---|
| Max flow | Up to 6.8 GPM |
| Low-flow ignition | Fires at 0.7 GPM |
| Efficiency | ≈0.80 UEF, non-condensing |
| Power | 120V outlet (exhaust fan & controls) |
| Certification | CSA; rated to 2,000 ft elevation |
Specifications verified against the linked source documents. See Sources below.
How much hot water you'll actually get
Usable flow drops as incoming water gets colder. Figures are calculated from rated output (150,000 BTU × 0.8 UEF) and labeled as such — not bench-tested by us.
| Temperature rise | Typical scenario | Usable flow |
|---|---|---|
| 35 °F | Warm climate (75 °F in → 110 °F) — capped at max | 6.8 GPM |
| 45 °F | Mild climate (65 °F in → 110 °F) | 5.3 GPM |
| 60 °F | Cool climate (50 °F in → 110 °F) | 4 GPM |
| 70 °F | Cold climate (40 °F in → 110 °F) | 3.4 GPM |
Usable flow at a 110 °F target: BTU × thermal-eff ÷ (ΔF × 500), capped at the 6.8 GPM maximum (non-condensing ~80%).
Pros
Cons
Buy it if…
- Small-to-mid homes wanting 2–3 fixtures on a budget
- Warm/mild climates where 6.8 GPM covers simultaneous use
- Installs with a nearby 120V outlet for the fan/controls
- Buyers who value 0.7 GPM low-flow ignition for small draws
Skip it if…
- High-altitude sites above 2,000 feet
- Efficiency-focused buyers (choose condensing)
- Cold-climate homes needing full 6.8 GPM in deep winter
Installation Requirements
Professional vs DIY
Propane and indoor venting make professional installation the safe route; a permit and correct vent termination are typically required.
Gas and electrical work should be done by a licensed professional, and most installs require a permit and must meet local building codes — DIY work can void the manufacturer warranty. Always confirm the unit's own manual for exact clearances, venting, and sizing.
What owners report
Themes summarized from retailer customer feedback (3.8/5 Amazon customer rating, 89 ratings, as of 2026-09-06). These are owner opinions, not our own bench testing.
Owners repeatedly note near-instant hot water at the tap and endless supply once installed, a big upgrade from an old tank.
The whole-home capacity and 10-year exchanger warranty at a low price are common reasons buyers choose it.
The ~3.8-star rating reflects a minority reporting installation quirks or reliability issues — professional install and proper venting help.
The 0.7 GPM ignition is praised for firing on small draws where cheaper units won't.
Eccotemp 45HI FAQ
Does the 45HI need electricity?+
Yes — a 120V outlet powers the exhaust fan, digital display, and control board. It's indoor and non-condensing, so it also needs proper venting (no condensate drain required).
How many fixtures can it run?+
Up to about 6.8 GPM — two to three fixtures in warm climates, tapering to one or two in cold weather as deliverable flow drops.
Can I install it at high altitude?+
It's certified to 2,000 feet. Above that, performance and efficiency can suffer, so it's not the right choice for high-elevation homes.
What's the warranty?+
10 years on the heat exchanger and 5 years on parts — notably strong for a budget unit. Register and install per instructions to keep it valid.
What hot-water flow can the 45HI deliver in winter?+
The 6.8 GPM rating assumes a warm inlet and a small temperature rise. Estimated from its 150,000 BTU/h propane input at about 0.80 efficiency, realistic usable flow is roughly 5.3 GPM at a mild 45 °F rise and about 3.4 GPM at a demanding 70 °F winter rise. That's genuine two-fixture capacity in mild climates, tightening toward a single strong shower where groundwater is cold. Because it modulates all the way down to 19,000 BTU/h and fires at just 0.7 GPM, it also handles low-flow fixtures without short-cycling — size it against your coldest incoming water temperature.
Product sources
Specifications verified 2026-09-06. Manufacturer documents are treated as the primary source for model specifications. Retailer pages are used only for customer ratings and owner-feedback themes.
- Eccotemp 45HI-LP — Amazon listing (accessed 2026-09-06)
- Eccotemp 45HI-NG — Ferguson (specs) (accessed 2026-09-06)
- Eccotemp 45Hi 6.8 GPM — Lowe's listing (accessed 2026-09-06)
Price range from leading retailers
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