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

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?



  1. Erin Campbell
    December 29, 2017 / 5:40 pm

    Hi! Wondering how things have been with this hot water heater in the over-a-year since you made this post. Have you heard of anything more affordable that would serve your needs? My tiny home will heat with wood, meaning there is the danger of freezing temps when I’m not there, so same issue as you are facing. Any more thoughts on your choice and alternatives are welcome and appreciated!

    • January 8, 2018 / 5:12 am

      I still love my water heater. And, actually, I installed the new version of this same heater in February of 2016. It works even better now! It’s quieter and it heats up more rapidly. I’m not sure the new version is officially on the market yet. You may need to call the company. I still highly recommend it when it comes to propane, tankless, instant water heaters for Tiny Houses. Otherwise, if you want cheaper, I would go with a tank water heater. Those have their downsides though – such as limited hot water.

  2. December 1, 2017 / 4:28 am

    How long (on adverage) would you say you have to refill your propane tanks? And what, if anything, else do you run off your tanks? We are going to use propane exclusively for our water heater and cant seem to figure out how often we will need to refill a 20 gal tank.

    • December 1, 2017 / 10:53 am

      When I’m just using the propane water heater and my propane stove top, I would replace my two 15lb tanks about every 6 weeks. When I’m also using my fridge on propane (it does both electric and propane), it goes in about half the time.

  3. Dawn Hart Jourdan
    February 23, 2017 / 5:34 pm

    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.

Leave a Reply