My Off-Grid Cabin’s Tankless Water Heater: Nearly 10 Years Later

The compact cabin layout places the bathroom directly beside the kitchen, keeping the three hot-water fixtures close together.

I connected the propane supply myself. There was no gas permit, no registration, no green tag, and no inspection or professional review of the work, then or since. That’s a fact about how this system came to be, not a recommendation for how anyone else should do it.

Why I Chose Propane and the Eccotemp L10

With no grid connection, my real choice was propane or a battery/solar-fed electric unit. I went with propane because:

• Propane was available in our area, and I didn’t want hot water depending on battery capacity or sun exposure.
• A tankless unit meant no tank standing hot around the clock — it only fires when a tap opens.
• The L10 is small enough to fit our bathroom without eating up space we didn’t have.

The model I bought and still use is the Eccotemp L10. The installed unit’s data label reads:

• Fuel: LPG/GPL
• Gas pressure: 11.24 inches W.C.
• Heat input: 20 kW
• Water pressure range: 20–80 PSI
• Flow: 2.65 GPM / 10 LPM
• Electrical supply: 3V DC — two D-cell batteries power the heater’s own ignition spark. The heater itself has no household electrical connection.

English and French labels on the installed L10 list LPG/GPL, 11.24 inches W.C., 20 kW, 20–80 PSI, 2.65 GPM/10 LPM and 3 V DC. The printed ISO 9001 wording is not treated here as proof of appliance safety certification or installation approval.

A conflict worth showing rather than smoothing over: the retained L10 box doesn’t fully agree with itself, let alone with the installed label. One panel on the box lists heat input as 75,000 BTU against the label’s 20 kW. On flow, one box panel reads “up to 2.65 GPM” — matching the installed label — while a separate box panel reads “up to 2.5 GPM.” I don’t have a model-era explanation for either mismatch, so all three flow figures and both heat-input figures are recorded here as what the evidence actually shows, not reconciled into one number.

The retained L10 box lists LPG, 75,000 BTU, 20–80 PSI and 3 V DC. This is period packaging evidence; it does not explain or resolve the difference from the installed unit’s 20 kW label.

The box also carries the wording “Portable or Permanent Mount” and “Outdoor use only.” I’m keeping that wording visible as period packaging evidence of how the unit was marketed at the time of purchase — it is not something I’m treating as approval of an indoor installation, now or then.

On water pressure: the installed label and the period box both show 20–80 PSI. Current Eccotemp guidance lists a 20–40 PSI operating range for current listed portable models. That relationship remains unresolved — I can say which figure came from my physical unit and which comes from Eccotemp’s current guidance, but not why they differ.

Current documentation: current Eccotemp L10 manual.

How the Cabin’s Water System Feeds the Heater

The heater is only half the story — the water has to get to it first.

Under the bathroom sink, inside the vanity, I built a manifold out of PEX pipe, brass tees, elbows and shutoff valves. It lets me isolate the kitchen sink, the bathroom sink, the shower, and the outdoor faucet independently. If one line has a problem, I can close that valve and keep using everything else.

The bathroom wall during the plumbing rough-in, showing the red and blue PEX runs before the wall finish was installed.

The PEX manifold inside the bathroom vanity lets me isolate the cabin’s individual water lines with separate shutoff valves.

For pressure and flow, the system runs on a Pentair SHURFLO pump and an accumulator tank. The pump currently installed carries a label reading model 4008-171-E65, manufactured in Mexico, dated November 18, 2020, with a listed shutoff pressure of 55 PSI. That manufacture date means it isn’t the original pump that went in with the heater back in 2016 — it’s been swapped at some point, and I don’t have a record of exactly when. The pump is a separate 115 VAC load, supplied through the cabin’s inverter, and is not powered by the heater’s two ignition batteries. The accumulator is a separate NMAT-075-125-01 tank, 0.75 litres (25 fl. oz.), rated to 125 PSI maximum working pressure.

Reference image of the compact pump type used to pressurize the cabin water system. The currently installed pump is identified separately from its photographed label as a Pentair SHURFLO 4008-171-E65.

The 0.75-litre accumulator model used with the cabin water system is labelled NMAT-075-125-01, with a maximum working pressure of 125 PSI.

The pump’s 55 PSI shutoff setting roughly matches how I’ve generally run the system, but that’s the pump’s own setting — not the same thing as the heater’s operating-pressure range.

Water source is seasonal:

• In warmer months, we draw from rain barrels outside, through a sediment filter.

Reference image of the inline garden-hose sediment filter used ahead of the pump on the seasonal rainwater supply.

• In winter, we switch to a freshwater tank in the loft above the bathroom.

The loft reservoir supplies fresh water during winter and when the exterior rainwater supply is unavailable.

• A crossover valve I installed in the bathroom lets us switch between the two sources.

For the full collection and storage setup, see how we harvest rainwater for off-grid living.

How I Set Up the System — Historical Case Study

Getting the heater up and connected in December 2016 came down to a handful of choices rather than a fixed sequence, and I want to describe it that way rather than as instructions.

I picked the spot on the bathroom’s outside wall, above the toilet, close enough to both the propane line and the main water supply that I wasn’t fighting long runs, and I secured the unit to the wall studs. For the exhaust, I built a stainless-steel air-gap port out of metal flashing so the hot pipe wouldn’t sit directly against the drywall or insulation — the exterior side is a dryer-vent base with a metal dryer vent and flapper to keep cold air and critters out. That was my own custom arrangement; it was never reviewed by Eccotemp, a technician, or an inspector, and I’m describing it as what I built, not as a method to copy.

Construction-stage view of the wall opening used for my original December 2016 exhaust arrangement. This historical photograph is not presented as installation guidance.

Exterior vent hood from my original December 2016 arrangement. The installation was not professionally reviewed or inspected.

Interior view of the exhaust connection and wall penetration from my original December 2016 arrangement. This historical photograph is not presented as installation guidance.

The completed bathroom installation as it appeared after the original build. I would not repeat this indoor placement today.

On the water side, PEX pipe and fittings tied the heater into the manifold and pump system already described. On the gas side, I connected the propane supply to the heater myself, and I performed a soap-and-water leak check during that original installation — a one-time check at install, and I haven’t kept a routine leak-check schedule since. Once everything was connected, I flushed the unit with cold water to clear out debris, then tested hot water at each fixture, starting low and working the temperature up until it was where I wanted it.

The Propane Supply: Historical Arrangement and Current Arrangement

This is a place where I want to separate what I remember doing in 2016 from what the current photographs actually show, because they aren’t quite the same picture, and I don’t want to blend them into one tidy story.

Historical, first-hand account: as I recall it, the water heater’s cylinder was originally kept inside our Lifetime storage shed, with roughly a 15-foot Mr. Heater hose routed from there to the heater, running underneath the cabin.

Historical reference — 2016 arrangement

Historical reference image of the extension hose and regulator associated with my original 2016 arrangement. It does not show or verify the present exterior cylinder, regulator or hose configuration.

Current, photographed arrangement: the recent photo review verifies a cylinder sitting outside, near the bathroom exterior wall, a grey MINIGAS-branded regulator marked “FOR OUTDOOR USE ONLY” carrying a CSA C/US mark, and a first section of black flexible hose leaving the regulator. What the photographs verify stops there — no uninterrupted route from that regulator to the heater’s indoor connection was photographed. That this exterior cylinder is in fact the one feeding the tankless heater is my first-hand account, not something the photographs independently establish.

The current exterior cylinder location beside the cabin and storage shed. I identify this as the cylinder serving the tankless water heater, but the photographs do not trace an uninterrupted route from this point to the indoor appliance.

Close view of the current cylinder connections and grey regulator. MINIGAS, FOR OUTDOOR USE ONLY and CSA C/US markings are visible; the exact regulator model and outlet pressure are not readable.

I also want to be clear about something the photos do show elsewhere: there is a multi-cylinder selector arrangement inside the shed, and that arrangement serves our cabin’s direct-vent wall heater — not the tankless water heater. I don’t want this article implying a continuity between the shed selector setup and the L10 that the evidence doesn’t support.

The cylinder near the bathroom wall carries a collar marking of TW 28.0 LB / 12.7 kg. That’s the cylinder’s tare weight — the weight of the empty metal — not its propane fill capacity, and I’m not using it as proof of size. Elsewhere in this article, where I refer to “the cylinder I have described as a 30 lb cylinder,” that description is mine, based on general recollection, not something the tare-weight marking confirms.

Historical Installation vs. Current Manufacturer Guidance

These are two separate things, and I want to keep them separate rather than let one stand in for the other.

What I did: the L10 has been installed indoors, permanently, inside our bathroom, since December 2016.

What Eccotemp’s current guidance says: Eccotemp’s current support documentation describes the L10 as part of its portable series, states that a portable tankless water heater should not be installed indoors or permanently, and notes that doing so can void the warranty and create a safety issue. Current guidance describes these units as meant to be taken down and stored in a warm, dry place after use.

Separately, on paperwork: no permit, registration, green tag, or inspection was ever obtained for this installation, and no professional reviewed the gas connection or the custom exhaust. That absence of paperwork is its own historical fact — it isn’t the same issue as the indoor/permanent-placement question above, and I don’t want the two facts read as one combined problem when they’re really two separate ones. Nine-plus years without a reported issue doesn’t turn either fact into proof of safety or approval.

Jurisdiction context: propane work in Nova Scotia falls under provincial fuel-safety law, with licensing for gas businesses and technicians and permitting tied to installation and alteration work. In the US, the relevant framework runs through locally adopted model mechanical and fuel-gas codes, plus the specific unit’s own listing and manufacturer instructions — adoption and amendments vary by jurisdiction, so there’s no single nationwide answer.

Carbon monoxide: CO is odourless, colourless and tasteless, and any fuel-burning appliance can produce it, with risk rising in enclosed spaces like cabins. We have two alarms — a ceiling-mounted combination-style alarm near the loft ladder, and a separate plug-in digital alarm — both visibly Kidde-branded in current photographs. I’d previously described one of these as a First Alert SC9120BCA installed in December 2025; that doesn’t match the Kidde branding the photographs actually show, and I’m leaving that conflict open rather than resolving it. (December 2021 refers only to when I replaced the heater’s ignition batteries — a separate, unrelated date.) Photographs confirm only that two Kidde-branded alarm devices are present; their exact models, dates, testing history and current operating condition were not verified, and alarm presence on its own doesn’t certify a safe installation.

What Worked Over Roughly Ten Years

With those separations in place, here’s the actual day-to-day experience:

• Hot water at the kitchen sink, bathroom sink and shower, on demand, without a tank kept hot around the clock.
• No ignition failures, nuisance shutoffs, leaks, freeze damage, soot, condensation, unusual smells, or CO alarms reported over that time.
• Winter interior cabin temperature is generally kept around 12°C, with no reported freeze-related issues at that range.
• A draining and isolation routine using the manifold valves when needed.

The kitchen sink is one of the three cabin fixtures supplied by the Eccotemp L10.

The bathroom sink is supplied by the same hot-water system, only a short distance from the heater.

The compact kitchen sits directly beside the bathroom; both sinks and the shower use the same tankless heater.

This is my own reported experience — not an instrumented test or a certification, and not a claim that the outcome is typical for anyone else’s setup.

Propane Use, Pressure, Flow and Temperature-Rise Observations

A cylinder I’ve described as a 30 lb propane cylinder has generally lasted about four to five months. That’s based on usually two occupants, roughly 12 occupied cabin days a month, about one shower per occupied day, plus normal kitchen and bathroom sink use. Change any of those numbers and the duration changes too — this is a personal observation with a stated denominator, not a forecast for anyone else’s household.

A few general concepts worth understanding when sizing a system like this:

• Temperature rise is the desired outlet temperature minus the incoming water temperature.
• For a heater with a fixed heat input, a larger required temperature rise generally means less available flow — the unit trades flow for heat, or heat for flow, depending on what the incoming water needs.
• Running more than one fixture at once means the heater has to support their combined flow at whatever temperature rise the incoming water requires — colder incoming water raises the required rise and can tighten how much simultaneous flow is realistically available.

I haven’t recorded instrumented flow, pressure, or temperature measurements at our cabin. I can tell you what the label says the unit is rated for; I can’t tell you exactly what we measured in use, because we didn’t measure it.

Problems, Limitations, Maintenance and Winter Operation

Maintenance record, as-is:

• Ignition batteries replaced once, in December 2021.
• I do not recall replacing the propane hose or regulator since the original installation.
• No flushing, descaling, or burner/heat-exchanger cleaning has been performed.
• The one soap-and-water leak check happened at installation, with no ongoing leak-check schedule since.

The bigger practical limitation, honestly, isn’t the heater — it’s water supply. When the rain barrels run dry, we don’t have an automatic backup. Fresh water has to be carried up the ladder in 5-gallon jugs to refill the loft reservoir by hand. That’s a real limitation of how our water system is built, not a failure of the tankless heater itself, and it’s the one that actually changes our day-to-day routine the most.

What I Would Choose or Do Differently Now

Being honest with where things actually stand: I would not repeat the same indoor placement if I were setting this up today. Given current manufacturer guidance against indoor and permanent installation of a portable unit, that’s the one thing I’d change outright rather than just flag as a limitation.

A few other things I’d do differently:

• I’ve thought about an outdoor, insulated compartment as a way to keep a portable unit accessible without bringing it inside — that’s a personal idea I find appealing, not a design I’ve built or tested, and not something I’m presenting as a recommended alternative.
• I’d keep better records from the start — leak-check dates, alarm model numbers and install dates, pump swap dates — the kind of paper trail that would have made a review like this much simpler.
• I’d get a clear, single-source answer on cylinder capacity rather than relying on a tare-weight stamp and memory.

Canadian and US Reader Notes

In Canada, and Nova Scotia specifically: propane and natural gas work is regulated provincially, with licensing for gas businesses and technicians and permitting tied to installation and alteration. Missing permit or inspection history, as in our case, is a documented fact here — it isn’t something this article resolves for you.

In the United States: the relevant framework runs through model mechanical and fuel-gas codes as locally adopted, plus the manufacturer’s own listing and installation instructions for your specific unit. Check your jurisdiction and your unit’s current manual directly — a Canadian off-grid setup, or any single code edition, doesn’t answer that question for you.

Everywhere: carbon monoxide is odourless and colourless. Working CO alarms near sleeping areas are a baseline if you’re running any fuel-burning appliance — not a substitute for correct installation and venting.

Conclusion

Almost ten years on, our Eccotemp L10 still supplies hot water to the kitchen sink, bathroom sink and shower, running on propane with no grid power involved. That’s the honest result of what I built in December 2016.

Two things are worth stating separately rather than folding into one conclusion. First, current Eccotemp guidance advises against indoor and permanent installation of this portable unit, and if I were starting today, I wouldn’t choose that same placement again. Second, and separately, I did not obtain a permit or an inspection for this installation. Those are two distinct facts, not one combined problem. If you’re weighing something similar, take this as one real account of long-term use, then read your own unit’s current manual and your local requirements before deciding what’s right for your situation.

If you have questions about our system, I’m happy to answer what I actually know — and just as happy to say when something is outside what I’ve verified.