Getting shower hotter

[Keithberk]

I have a 2017 24 mxz with a 575 and the shower is luke warm at best.  Any way to get this hotter?

[UWSkier]

unfortunately when you're dealing with a heat exchanger, there's not much you can do to increase the heat.

Can do what we do and bring a cooler full of piping hot water and a cup.  Dump some in bindings and gloves before you put them on.  Wet gloves after a set go in the cooler (heater).

[Eagleboy99]

There is always a solution.    https://www.eberspaecher.com/en/products/fuel-operated-heaters/product-portfolio/water-heaters.html

[ahopkins22LSV]

2 hours ago, Eagleboy99 said:

There is always a solution.    https://www.eberspaecher.com/en/products/fuel-operated-heaters/product-portfolio/water-heaters.html

Where do you plan on routing the exhaust since it’s a heater that works on combustion? Oh and where do you plan on mounting it? Totally not designed for application in a boat. 
 

To the OP, I’d look at maybe adding a circulation pump if there isn’t one already. Personally I’ve always skipped the heater option on our boats and follow what UW does. We ski into November/December here in Michigan and start as soon as the ice leaves, sometimes in March. I just use a cheap 48 can Coleman cooler half-3/4 full of hot water from the house. Toss you gloves in and binding liners pre set and get your feet and hands in the cooler again after the set right away. Since I’ve bought my excl wetsuit, I don’t put warm water in it anymore. It barely lets in water as is so I wear that down into the 50s for water temp then switch to my dry suit after that. 

[UWSkier]

You guys understand he's talking about a shower, not a heater, right?  Heater uses engine coolant which will be at engine temp.  Should be plenty warm.  Shower relies on pulling lake water across a heat exchanger.  The water flowing through a heat exchanger doesn't have enough time to come up to a nice toasty temperature before you use it to warm your digits or your wet suit.

Not a lot you can do unless you can add a secondary heat exchanger that would increase the amount of time the lake water has to absorb heat from the engine coolant.  You'd want it to only "exchange" with water destined for the shower and not all raw lake water.  Concerns there would be adding the plumbing to your cooling circuit and the potential for air pockets, leaks, etc.

[Keithberk]

1 hour ago, UWSkier said:

You guys understand he's talking about a shower, not a heater, right?  Heater uses engine coolant which will be at engine temp.  Should be plenty warm.  Shower relies on pulling lake water across a heat exchanger.  The water flowing through a heat exchanger doesn't have enough time to come up to a nice toasty temperature before you use it to warm your digits or your wet suit.

Not a lot you can do unless you can add a secondary heat exchanger that would increase the amount of time the lake water has to absorb heat from the engine coolant.  You'd want it to only "exchange" with water destined for the shower and not all raw lake water.  Concerns there would be adding the plumbing to your cooling circuit and the potential for air pockets, leaks, etc.

I thought the malibu one used the water that goes through the motor.  I would figure that would end up hotter than 80 degrees.

[shawndoggy]

Just now, Keithberk said:

I thought the malibu one used the water that goes through the motor.  I would figure that would end up hotter than 80 degrees.

water doesn't go through the motor with closed cooling.

[ajive]

You probably have the Raptor motor, right?  The shower pulls from the big HX block at the aft.  If the boat is up to temp and you turn off the engine so the water goes stagnate in there it should heat up pretty well... you could also run the boat hard for a bit before showering so the engine has plenty of heat to remove.  I feel like my shower get's pretty toasty... it's not quite as ball burning as my old '13 was (I assume this is due to the closed cooling taking a good chunk of the heat) but not bad. 

[Rednucleus]

Are the exhaust manis raw water cooled? Maybe shower water could be pulled off that location??

[R44Ryan]

On 1/9/2020 at 3:50 PM, Rednucleus said:

Are the exhaust manis raw water cooled? Maybe shower water could be pulled off that location??

I was thinking the same thing Rednucleus. I was looking to make a shower for my 2002 Response with the LS1 and was hoping I could pull the hot water from there. Maybe I can't?

[R44Ryan]

On 1/8/2020 at 5:17 PM, Eagleboy99 said:

There is always a solution.    https://www.eberspaecher.com/en/products/fuel-operated-heaters/product-portfolio/water-heaters.html

Haha. True! But looks expensive for some reason!

[EthanMitch]

On 1/9/2020 at 10:42 AM, ajive said:

You probably have the Raptor motor, right?  The shower pulls from the big HX block at the aft.  If the boat is up to temp and you turn off the engine so the water goes stagnate in there it should heat up pretty well... you could also run the boat hard for a bit before showering so the engine has plenty of heat to remove.  I feel like my shower get's pretty toasty... it's not quite as ball burning as my old '13 was (I assume this is due to the closed cooling taking a good chunk of the heat) but not bad. 

@ajive does it pull hot water immediately after the HX? Do you have any pics. It appears on my 2018 raptor that raw water is sent to exhaust manifolds after the heat exchanger. If true, could the water be hotter if pulled after/from exhaust? Thanks for your thoughts.

[ajive]

11 hours ago, EthanMitch said:

@ajive does it pull hot water immediately after the HX? Do you have any pics. It appears on my 2018 raptor that raw water is sent to exhaust manifolds after the heat exchanger. If true, could the water be hotter if pulled after/from exhaust? Thanks for your thoughts.

You may be correct, I just tried to trace the lines and they go under the engine and I didn't feel like taking the sides off and crawling under, but I feel like I did that for this post all those years ago 😂

When I winterize I run the shower first and it drains the HX completely so pretty confident it's tied in underneath.

If my quick look was enough, I think the only place you'll find hotter water is at the top of the HX.  I think this is just an artifact of the combined cooling system.

In my 2013 you could install a bypass wye and pull straight from the exhaust instead of the outlet which helped a lot, but this system is more complicated and I've never seen a canned aftermarket solution like that for this motor.

 

[justgary]

1 hour ago, ajive said:

I just tried to trace the lines and they go under the engine

If you are describing a crossover hose that goes from one manifold to the other, that would be a great place to get heater water.

Note to DIYers: your exhaust water will be in the neighborhood of 160°F.  I would think it would be important to ensure that the mixer keeps the water under about 105° or so.