Mr. Heater BOSS Portable Hot Shower System – Review

Mr. Heater BOSS Portable Hot Shower System – Review

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We chose the Mr. Heater BOSS-XCW20 as hot shower system for our self-converted van. We’ve been living in our van full time since September 2017, riding our mountain bike almost each day, so showers are not optional… we had plenty of time to test the shower, it’s time for a review!

Nothing to see here… keep reading for more!


Safety Features

  • Over temp cut-off (protect against scalding water)
  • Flow detector (propane will cut-off if no water is circulating)
  • Tip Switch (propane will cut-off if the unit flips over)
  • Oxygen depletion sensor


  • Dimensions: 19.5″ (length) x 13″ (height) x 10.5″ (width)
  • Weight: 22 lb
  • 18,000 BTU (can raise source water by 45F)
  • Portable (it has an internal battery, runs from a small 1 lb camping propane tank and comes with its own water pump). Note: we run it from our 20 lbs propane tank because it’s more cost effective and environmentally friendly
  • Deliver 1.18 gallons per minute (it’s not as powerful as a home shower, but it’s OK as water is a precious resource in the van!)

Have a look!

Mr Heater BOSS-XCW20-5

Mr Heater BOSS-XCW20-2
Mr Heater BOSS-XCW20-3
Mr Heater BOSS-XCW20-6
Exterior Shower Campervan Conversion (9)
Our “Permanent” setup: no need to take the Mr. Heater or the Aquatainer out of the van. On the negative side, we need to connect the propane and the water each time we want to shower: these extra steps are getting a bit irritating in the long run…
Guacamole Shower-01-1200x800
No shower curtains needed here…

Before we go any further, there are certain characteristics common to all “instant” propane hot water system:

  • They’re not recommended for inside: this is to prevent carbon monoxide poisoning (resulting from burning propane). If you decide to use it inside, make sure to vent the room!
  • Water initially take about 5-10 seconds to get hot, so that’s 5-10 seconds of wasted water. If used only as a shower system, that’s no big deal; if used to wash hand or rinse dishes frequently, that’s wasted water each time. This is something to consider if designing a water system for your campervan…
  • Don’t let them freeze! Like any plumbing, it will crack and leak. (we plan on keeping the inside of our van above freezing temperature, so beer don’t explode!)

What we Like

  • Mr. Heater is a well established brand (they make the very popular Buddy Propane Heater (Buy on Amazon). We carry that as a backup heater) and are renowned for safety features in their appliances, so we feel safe using the Mr. Heater BOSS.
  • The internal battery can be recharged from a 120V outlet or a 12V outlet. Mr. Heater claims the shower can run for 40 minutes on one charge; we haven’t tested that but we feel it’s true as we don’t have to charge it often.
  • It’s portable! This was useful on a few occasions. (We brought the shower inside a shower facility at a trailhead where only cold water was available. It was too windy and cold to take our shower outside). We also plan on a winter setup where we will bring the unit in front of the van.
  • The shower head has an ON/OFF switch integrated, it can be used to shut-off water temporarily (using this switch will block water flow but will not turn the pump off).

Mr Heater BOSS-XCW20-7

  • The unit has a faucet on the side (to dispense hot water for washing dishes or washing hands)

What we Don’t Like …

  • The Mr. Heater BOSS must be run with it’s own water pump. In other words, it cannot be integrated to a RV pressurized water system and therefore a separate water container must be used (we use a 7 gallons Aquatainer (Buy on Amazon)). On the bright side, having an extra water container gives us more autonomy (more water) and it’s easier to fill if we cannot find a faucet to fill our 25 gallons water tank.
  • The water temperature increase (45F) is enough to get a nice hot shower. However, we found 45F increase will get us a warm (not hot) shower in autumn/spring just when we really wished we had a HOT shower (because it’s colder outside…). Why? Because we carry our water below the bed: it’s the coldest area in the van, therefore our water get really cold there. Fortunately there is a solution! We use the Mr. Heater to pump water from the Aquatainer back into the Aquatainer: this pre-heat the source water. Voilà!
  • The hose between the heater and the shower head is made of silicone: it’s resistant, but it has a tendency to kink easily near the shower head and that will block water flow.

Models & Where to Buy

DISCLOSURE: This post contains affiliate links, which means that if you click a product link and buy anything from the merchant (Amazon, eBay, etc), we will receive a commission fee. The price you pay remains the same, affiliate link or not.



There are 3 models available:

Mr.  Heater  BOSS-XB13

  • 12,000 BTU (35F increase claimed)
  • 0.6 gallons per minute
  • No faucet

    Mr Heater BOSS-XB13 Shower
    Mr Heater BOSS-XB13. Buy on Amazon.

Mr. Heater BOSS-XW18

  • 17,000 BTU (42F increase claimed)
  • 1.18 gallons per minute
  • No digital display
Mr. Heater BOSS-XW18. Buy on Amazon.

Mr. Heater BOSS-XCW20

  • 18,000 BTU (45F increase claimed)
  • 1.18 gallons per minute
  • With digital display
Mr. Heater BOSS-XCW20. Buy on Amazon.


The Mr. Heater BOSS-XB20 includes everything needed: water pump, battery charger (120V or 12V) and the shower head. All you need is propane and water! In other words, there is no installation required.

If you wish to use a refillable propane tank (5, 11 or 20 lbs) instead of the small 1 lb camping propane cylinder, all you need is the following hose (no regulator needed: plug the hose from the tank to the Mr. Heater BOSS):

propane hose
Propane hose adapter. Buy on Amazon.

We got this neat holder with suction cup, it works great! (Hint: apply water on the suction cup to get full holding power)

Exterior Shower Campervan Conversion (1)
Holder with suction cup. Buy on Amazon.


If you’re reading this, it means you can operate the internet; there is no doubt you will be able to operate the Mr. Heater BOSS! It’s fairly straightforward.

1- Make sure that the propane and the water pump are connected at the back of the unit (and that the water pump is submerged in water);

2- Make sure that the shower head is connected at the front of the unit;

3- PLEASE make sure you have a towel handy so you don’t have to yell at your better half to bring you one 😛

4- a) Turn power on. b) Select shower or faucet output. c) Select temperature range. d) Press “pump” to start showering;

Note: The unit will sometimes throw an error code at first utilization; that’s because water took too long to reach the heater (hose is priming) and propane will shut-off for safety sake. Just power the unit off and on to reset it.

5- To stop the water, press pump again. Or you can use the switch on the shower head (it blocks the water flow, but the water pump keep pumping. So we prefer to use the pump button).


We’ve been using the Mr. Heater BOSS since June 2016 and we had no issue so far. In fact, reliability is one of the reason we went for Mr. Heater brand, so we’re confident it will pass the test of time. To stay updated: Subscribe to our Mailing List.


We were really tempted by the Eccotemp L5 (Buy on Amazon) as the specifications are very similar (BTU, water flow, etc), but finally went for the Mr. Heater BOSS because the portability was the deal breaker. Here are the Eccotemp L5 pros and cons:


  • Can be integrated to the pressurized water system
  • Smaller than the Mr. Heater BOSS (no extra water container required)
  • Lower price tag, high quality


  • Not as portable as the Mr. Heater BOSS
  • If integrated to the existing pressurized water system, the water cannot be recirculated to pre-heat the source water
Eccotemp L5
Eccotemp L5 without pump (to use in a pressurized water system). Buy on Amazon.
Eccotemp L5
Eccotemp L5 with pump and strainer (to use as a standalone portable system). Buy on Amazon.


On Second Thought

We really enjoyed using the Mr. Heater BOSS and highly recommend it, but we finally installed an Eccotemp L5 instead because:

  1. After 10 months we realized we don’t need our shower to be portable.
  2. We also realized finding water is fairly easy, so we don’t really need the extra 7 gallons Aqua-Tainer.
  3. Having to connect the propane and water each time is a little irritating.

Again, there’s nothing wrong with the Mr Heater BOSS if it answers your needs!

Here is our review of the Eccotemp L5:

Thanks for reading!

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About us



Hello! We’re Isabelle and Antoine 🙂 In 2017, we sold our house (and everything in it), quit our engineering careers, and moved into our self-built campervan. Every day is an opportunity for a new adventure... We’re chasing our dreams, and hopefully it inspires others to do the same!

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Thanks to all of you, we managed to negociate group discount on these. Strength in numbers!

4 thoughts on “Mr. Heater BOSS Portable Hot Shower System – Review”

  1. I found this unit to be frustrating beyond all belief. Throws the E2 error code, and once it does, forget it. Look at reviews on Amazon, and other complaints online with this issue. Its good as a boat anchor, maybe.

  2. You could plumb a recirculating valve and loose no water for the few seconds the water takes to heat up.
    A tee and 1/4 turn valve with pipe from the hot side of the faucet back to tank. Or even a 12v solenoid and push button instead of a manual valve


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