Our Water Heater: Why we love it and how we almost killed it

There are many choices out there for tiny house appliances, and one of the most important (especially if you like hot showers) is your water heater. In a standard size home, you’ll usually find a gigantic water heater gargling and humming in the basement. In a tiny home, you have to think… well…. tinier. This might mean going tankless or purchasing a small tank water heater. For our tiny house, we went with a tankless propane water heater.

Our Tiny House Propane Water Heater

Our tiny house water heater is the PrecisionTemp RV-550 NSP. There are a couple of special features to this particular instant propane water heater that makes it the best choice for tiny homes.

propane water heater

PROS of the PercisionTemp Propane Water Heater:

  1. Water Temperature Rise. The PercisionTemp has an 88° F temperature rise per gallon per minute. That’s impressive and uncommon for such a tiny unit.
  2. Limitless, (Almost) Instant Hot Water. The PercisionTemp is capable of heating water within 10 seconds, limitlessly. Other instant units take up to 45 seconds to heat water.
  3. Compact. The PercisionTemp is a small 14″ cube. It fits easily under our kitchen counter.
  4. Floor Vent. As with all propane units, the PercisionTemp requires exterior ventilation, but this unit actually vents through the floor! That means you don’t need to cut a hole in the side of your Tiny House (which can be unattractive).
  5. Anti-Freezing Protection. The PercisionTemp will detect when it’s about to freeze and start up to protect itself. Keep in mind, freezing your unit is not covered under warranty. Read on for how we managed to screw this up.
  6. Needs almost no electricity. A small amount of electricity is required to ignite the unit. This is common with propane appliances. A 12-volt battery is sufficient. We can use this unit while running on solar, which was ideal for our situation.

CONS of the PercisionTemp Propane Water Heater:

  1. Expensive. The PercisionTemp retails at $1,150, making it one of the most expensive appliance choices for tiny homes.
  2. 10 Seconds to Heat Up. Even though 10 seconds is not a long time to heat water, a tank water heater would be absolutely instant (though limited by the tank size). When we shower, we like to take navy showers – meaning we turn the water off as we lather up. Every time we turn the water back on, we endure 10 seconds of cold water before the hot water kicks in. It’s not exactly a spa shower, but it’s efficient and eco-friendly.
  3. Need 0.5 gpm to work.  Extremely low-flow faucents (0.5 gpm or under) will not trigger the unit.

How we broke our water heater from a stupid mistake

This past winter we parked our Tiny House in the Colorado Rockies. Usually we kept the house warm, but from November to December we left the house unattended as we traveled to Europe. We didn’t winterize the Tiny House, because we were hoping our Envi heater could keep it from freezing while we were away. That was a mistake.

In late November, nightly temperatures dropped to below 0°F. Our Envi heater couldn’t keep up and the internal house temperature dropped to below freezing (32°F). Our water heater tried to trigger itself to ignite to prevent itself from freezing but failed. The trouble was, our propane tanks were freezing as well. At the time, we didn’t protect our tanks with heat blankets so their efficiency was significantly reduced. Our PercisionTemp was not recieving enough propane pressure to ignite, and eventually, the pipes inside the unit froze and burst. Water from our tank emptied through the water heater unto the ground beneath our trailer. Luckily, our house did not flood (thanks to the water heater’s floor venting).

propane water heater
The copper piping inside the unit burst from freezing

When we returned from our trip, Guillaume was able to fix our water heater by purchasing a few parts from PrecisionTemp and spending the afternoon as a DIY plumber. The total damage cost us $235 (plus shipping).

propane water heater

This mistake could have been prevented a number of ways:

  1. Occupants. Had we been around, the problem would have been noticed and rectified before the pipes froze.
  2. Winterizing the unit. We could have drained the unit and filled our plumbing with antifreeze.
  3. Propane blanket. Had we purchased a propane heat blanket before we left, the pressure would have been enough to keep the water heater from freezing. Our propane efficiency increases dramatically with the help of the blanket.

Propane Water Heater Tank Blanket

*Click here for more advice on Tiny House cold climate prep

Which water heater are you going to use in your Tiny House?

29 thoughts on “Our Water Heater: Why we love it and how we almost killed it”

  1. A person’s profession and income generation and their preferred lifestyle need not differ: Jenna and Guillaume have masterfully created a life for themselves that does both!
    Their choice to live simply and be mobile is chosen carefully to enhance their lives and reach their goals. A non-mobile house “set in the back woods” is at odds with their lifestyle, and doesn’t compare.
    Congratulations on your success, Jenna and Guillaume! 🙂 Many admire your achievement, despite the envy of these dissenters of the (mobile) tiny house movement.

    1. The tanks did not freeze, but they got so cold that my water heater did not receive enough propane pressure and was not able to turn on. The pipes inside my water heater froze, because the heater was not able to turn on and heat up, and the pipes burst. Make sense? So if the propane tanks are kept warm, they can give enough pressure to the heater so that it can turn itself on and prevent freezing.

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