Portable Water Heater for a Hot Tub or Pool

14,662

26

33

I recently purchased a portable hot tub - Intex PureSpa 6-Person Portable Inflatable Bubble Jet Ho t Tub. While looking at the specs and reviews I was concerned about the heating capacity of the unit. The 1,300 Watt heating unit only heats the water 1-2 degrees Fahrenheit an hour. Customer reviews also indicated they had a significant increase in their electrical bill. This information lead me to come up with a portable water heater solution. I am not a handyman by any means so suggestions and optimization ideas are very welcome. Please let me know what you think for my first Instructable.

Step 1: Pieces and Parts

Here are the basic pieces that I used to make the portable hot water heater.

Camplux 5L 1.32 GPM Outdoor Portable Propane Tankless Water Heater

Flojet 03526-144A Triplex Diaphragm Automatic W ater System Pump, 2.9 GPM 50 PSI, 12 volt DC

4 - 1/2 to 1 1/4 " stainless steel hose clamps

2 - 1/2" galvanized coupling

2 - 1/2" Male NPT X 1/2" Hose Barb

2 - 10' braided vinyl tubing 1/2" inner diameter

Kastar AC Adapter, Power Supply 12V 6A 72W

Teflon Tape

Wrench and Screw Driver

Step 2: Making the Water Connections

Apply Teflon tape to the threading and hand tighten the 1/2" coupling and 1/2" to hose barb to the water inlet and outlet on the water heater unit. Affix the hose to both of the hose barbs and tighten with the hose clamps.

Step 3: Connect Hosing to the Pump

Using the hose barb connections supplied with the pump attach the hoses and tighten with hose clamps. Ensure you follow the directional arrow that indicates the flow of water through the pump so it draws water from the water source and into the water heater.

Step 4: Connect the Propane and Check for Leaks

Connect the supplied propane supply line to a 20 lb propane tank and check for leaks by using soapy water on connection points. If you see bubbles turn off the propane and tighten that connection point, do not overtighten. Once no leaks are detected mount it in a safe location. It must be mounted outside where adequate ventilation is provided. I had plenty of space under my deck where the heat could dissipate and not overheat the wood.

Step 5: Attach the Power Supply to the Pump

Attach the power supply to the water pump. The outside of the barrel is negative (-) and the inside is positive (+). Do not plug the pump in until all water connections are attached and the suction end is submerged in the water.

Step 6: Check All Connections and Turn It On!

Check all connection points to ensure they are adequately tight and not leaking. Ensure propane is turned on. If not already installed place the 2 D cell batteries in the water heater. Ensure both ends of the hose are underwater. The suction hose must remain submerged at all times.

When you are ready to connect the pump power supply and water will begin to flow. Once water flow is detected in the water heater it will auto start the flame. You can view this in the flame window on the front of the water heater unit.

Relax in whatever you are heating and watch the temperature rise. Be careful, if you have the water flow turned low and the gas high it is capable of producing hot enough water to scold and burn. This should be supervised at all times by a qualified adult.

Enjoy! :-)

Share

Recommendations

  • Colors of the Rainbow Contest

    Colors of the Rainbow Contest
  • Beauty Tips Contest

    Beauty Tips Contest
  • Fandom Contest

    Fandom Contest

33 Discussions

0
None
jimrock66

2 months ago

I upgraded the unit a little. I put a basked on for the propane tank. Now moving the unit is so much easier . I put a Camplux 10L on instead of the 5L . I wanted to have a digital reading and a more powerful heating system. It is 68000 BTU max Enough to heat a medium size above ground pool. I figured out that I needed screening for the pump so that foreign objects don't get caught in the pump. A timer for the 20 minute shut off. The timer is set at 19 min on and 1 min off in a loop. the heater continues working without resetting. I also put a garden hose bypass on the unit so you can either use a hose or the pump.


It took a while the pumps were the worst part. But I think this unit is a performer.

20190413_162325.jpg20190413_162334.jpg20190413_162340.jpg
0
None
millingby

10 months ago

How did you bypass the 20 minute auto shut off feature of the water heater?

2 replies
0
None
jimrock66millingby

Reply 2 months ago

I used a timer 19 min on 1 min off then back on

0
None
weber713millingby

Reply 10 months ago

Great question. I was originally worried about the auto shut off, however, it has not been an issue. I typically let the unit run for an hour and then allow the system to rest for a little while before restarting. I have not had an issue of it shutting off at the 20 minute mark.

0
None
gloriag22

Question 4 months ago on Step 6

I did your set up and all worked great until the pump stopped. I used a pump from an RV I had. Doesn't seem like the heater is letting the water go through. Plenty of pressure in the inlet hose and the hose from the pump to the heater. The heater will kick on and run for a while and shut off. Water is just a trickle coming from the heater. Any ideas. I was wondering if you could use a pump designed for actually moving water from one place to another. I saw a 110v pump on
Amazon that seems like it would fit the bill.
https://www.amazon.com/dp/B0747P8C65?psc=1&pf_rd_p=7ebdab82-de3b-42f2-8032-aa63ae38b0fa&pf_rd_r=C22929MTCP8358FXWTH6&pd_rd_wg=LyM3q&pd_rd_i=B0747P8C65&pd_rd_w=AXJIf&pd_rd_r=b74266fb-9ef5-4fc4-968d-1a053fc16ab2&ref_=pd_luc_rh_crh_rh_sbs_02_03_t_img_lh

1 answer
0
None
weber713gloriag22

Answer 2 months ago

That's curious, did you turn the flow all the way up on the heater unit? Did you add any hardware that may restrict the flow or did you use any smaller hoses? I have not had that issue I wonder if you have a heater unit that is not working appropriately. I have been able to turn the heater from the lowest flow to the highest and it was able to support both. I do caution you that if you keep the pump running full blast by keeping the heater flow on high it may result in the pump overheating as other folks have identified on here.

0
None
jimrock66

3 months ago

Built one just like you did, but I put mine on a hand truck. Thanks for the idea. I tested it on a tub of water, and within minutes the water was steaming. Going to use this on an Intex six person bubble tub. I love the hand truck setup.

20190223_141252.jpg20190223_141257.jpg
1 reply
0
None
weber713jimrock66

Reply 2 months ago

What a great idea to make it nice and portable!

0
None
jimrock66

3 months ago

Everything seemed to work well then the Flojet motor kept overheating every 15 minutes and stopping for about 15 minutes. Going to try the Camplux motor next. This whole project is a great idea if I can get it to work right. Any other suggestions.

1 reply
0
None
weber713jimrock66

Reply 2 months ago

I have mad my pump overheat and cut off but that's around 45 minutes to an hour of continuous use. There was a suggestion made by another commenter to change the pump out for a hot water circulator that might take care of the pump issue as a whole. Otherwise I place my pump directly on a large stone which helps control its temperature a little bit.

0
None
gloriag22

Question 3 months ago on Step 6

That is exactly what I did. I sure wish it work right thou. Worked right the first time I used it. Now it runs for a few minutes, maybe, then the water coming out of heater starts to stutter. Then the flame goes out. Pump starts to pulse. I have had 4 different pumps and at least 3 different power supplies on it with the same results. I now have exactly the same parts you used. Same result. The only thing different is I am using 5/8" hose instead of 1/2". Starts stuttering then shuts off. Any help would be greatly appreciated.

5 answers
0
None
Jimbo95220gloriag22

Answer 3 months ago

12 volt rv water pumps a not generaly used on hot water, that could cause the problem. There is hot water circulation pumps for hot water heaters for homesto circulate hot water to distant bathrooms. $70 range might help

0
None
gloriag22Jimbo95220

Reply 3 months ago

Well I had one of those hot water pumps and it did the same thing. I got the exact same pieces this guy that did the instructable has. With one exception and I think that is causing the problem. I used garden hose and he used reinforced vinyl tubing. I think now the problem it that the hot water is collapsing the hose and the water can't get through. Thanks for the answer tho

0
None
Jimbo95220gloriag22

Reply 3 months ago

The 12volt pump shut off on pressure. If the intake is collapsing i think the pump wouldn't shutoff. They will shut off if they overheat and come back on after it cools. That info is from shurflow site

0
None
jimrock66Jimbo95220

Reply 3 months ago

Mine is over heating and comes back as it cools. I am using the reinforced vinyl tubing.

0
None
weber713jimrock66

Reply 2 months ago

I agree that the hoses may be collapsing or restricting flow which may cause that shudder and shut down. The heater unit indicates it has an auto shut down at 30 minutes or so, I have not seen that with my unit. The hot water circulator pump is a great idea I did not know such a thing existed. I will purchasing one of those to see if it helps the system run better and prevents the pump from getting hot it tends to do. Thanks for all of the feedback and comments!

0
None
Bklanker

4 months ago

Would it be possible to use this set up for a small above ground pool? Could the pool pump be used in place of the Flojet pump?

1 reply
0
None
weber713Bklanker

Reply 4 months ago

Conceptually yes I do think it should work. I was looking to do the same with my pool. I have not yet tried it but had a few thoughts; I was planning on adding a three-way valve ( https://amzn.to/2MJg8ns ) to divert water to the heater and have an inline hook up. I was thinking about placing it after the filter (to protect the heater from impurities in the water) and before the chlorinator ( to reduce build up of calcium in the heater). I may tackle this in an instructable in the spring. If you do end up doing it let me know how it works :-)

0
None
bsawhill

Tip 5 months ago on Step 3

There are actually THREE sections of hose, not two: one from the heater to the pump, one from the heater to the tub and one from the tub to the pump. Or am I seeing things?

1 reply
0
None
weber713bsawhill

Reply 4 months ago

You are not seeing things you are 100% correct. Thanks for noticing that :-)