Mr. Heater BOSS Portable Hot Shower System – Review


Mr. Heater BOSS Portable Hot Shower System – Review

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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19 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

  3. Hi,
    for my van its not possible to connect the gas to a big gas bottle, so it s important the amount of gas needed..have you an idea of how much gas for lt of hot water it s necessary?. i had the Ecotemp 5 but for a shower i spent 2,60 euro of propane(a full 250 gr cp250 bottle for a shower for 2 people) .. so it s not sustenible for cost.. but for rubbish production…) tranks!

  4. Hi guys!

    I know it’s probably obvious when you have the unit in front of you 😉 But could you detail a little bit what’s the process you do to recirculate the water to get it hotter then 45F ? Do you just create a loop, run the unit and then replug the shower head and then you’re good to go?


  5. Hey guys,
    Thanks so much for this platform to share and learn. Love your ideas.
    Considering hot water options on my current ( It’s in the driveway but just doing design and taking measurements at the moment) 350 High Top Extended.
    Wes Greenwood,
    Regarding the Ecotemp, what are your exhaust plans? Does it slide out of the back? I’ve never much liked these but they are a logical option here.

    Aside from perhaps the location out back, is it feasible to use the Boss for hot water instead of the kettle? Convenient enough to fire up and grab a liter of hot water? If the Heater is full time plumbed to propane and water?

    • I wouldn’t use the Mr Heater as hot water source (sink). It takes a few seconds (5-15) to achieve high temp (so there is some water waste) and while it gets hot enough for shower, maybe not hot enough to wash dishes.

  6. Im planning to run a water line to the back of the van.

    The water tank is essentially in the middle of the vehicle, so I was going to have a second utility cabinet st the back to house the eco temp heater, the water tank fill line and a water outlet tap to hook the eco temp to.

    I’ll let you know how it works.

    We have the entire van spray foamed, all interior walls and the whole underside of the living space. It was -12 here the other day, I drove the vehicle for 2 hours, and with the vehicle heat vents running( not the Webasto) it was comfortable in the back of the van.

    So I’m not sure the water tank will ever get much cooler then the ambient temperature of the interior.

    I’ll keep you posted on how it works though. We should be a little better at social media posts after Christmas as this will be our full time thing

    Ps… good to know about the amazon thing. We have definitely directed some money your way so far then.

  7. Antoine!

    We need to buy our eco temp on demand heater.

    Put a link up for one without the pump and strainer and we will gladly use your affiliate link.

    Our conversion is coming along. Just built all of the boxes for the kitchen cabinets last week.

    I’m finished work on Friday so it will be non stop work on the van until we hit the road( hopefully by mid January)

    We are so sick of the winter already and your pics of Utah are getting us antsy to hit the road.

    • DONE! The link is up! Thanks for asking 🙂 (but we make a commission on ANYTHING you buy on Amazon within 24 hours after you click on our link! or until you shut your browser)

      Do you plan on connecting the Eccotemp to your sink? I would really like to know how it performs (especially interested to know if there is a long delay before water gets hot).

      Keep up the good work!! Keep in touch!

  8. Very understandable and thorough review…thanks! Well thought-out design (the drawer, extra water tank, and the whole shower set-up)…great!

  9. How often are you tempted to build out a water system that would also allow for hot sink water? The Mr. Heater is perhaps portable enough to place on a counter if needed, but I imagine using it’d be too inconvenient to use for this purpose frequently. I know you have a builder’s mind, and are probably always thinking about how to improve your routines.

    Said another way, are you totally cool with not having hot dish water?

    • We quickly got used to it. It takes just a few second to get hot water with the kettle on the stove. I mean, of course it would be nice to have hot water from the faucet, but this means either:
      – instant propane hot water system, but it takes a few seconds to heat = water waste.
      – hot water tank = energy waste (electrical or propane) and loose precious room space.
      – Webasto space/water heater = expensive (and we had issues with our Air Top)

      The only major downside of not having hot water I see is for rinsing dishes: it makes it very hard to dry… other than that, I don’t miss it. Using the kettle is time and energy efficient.

      Hope that helps!!

  10. Merci pour le review!! C’est justement un des trucs qui me manquait et c’est un très beau produit! De plus, le prix est très bon ces temps-ci sur Amazon! 🙂


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