[Dave_E]

Hi All,

My 36 year old boat was made with things like wire nuts for the electrical system (I kid you not), and copper tubing for the hot water system. I'm seeing places where I suspect the hot water copper tubing will fail at some point. The green corrosion in a couple places has obviously taken it's toll on the OD of the tube. I know there is the hot water PE hose (I think I said that correct), the "red" stuff (blue is cold). But here's the deal: the water from the 180 degree engine running temp makes the water in the water heater WAY hot. Even though I installed a mixing valve and have the cold turned all the way on, the water coming out is still maybe too hot for that kind of hose?

What do you all have on your boats (that have a water heater that is electric and engine water heated)? Ever had problems? Thanks.

Dave

 

[Faster]

We're using the red Pex tubing in our HW piping without issue. However it sounds odd that your hot is "too hot" even with full cold on and mixing. I'm thinking somehow the hot is pushing back the cold and not actually mixing, but can't think why that might be... Single pressure water pump, I assume?

 

[RichH]

Most 'polymer' water lines have a maximum limit of 170°-180°F, at which temperature the 'polymer' begins to soften. This includes PE, UHMWPE, etc.

PEX and CPVC can be used to a max. of ~200°F

The 'usual' marine store clear / reinforced PVC hose has only a 150°F temperature limit.

 

[Dave_E]

Most 'polymer' water lines have a maximum limit of 170°-180°F, at which temperature the 'polymer' begins to soften. This includes PE, UHMWPE, etc.

PEX and CPVC can be used to a max. of ~200°F

The 'usual' marine store clear / reinforced PVC hose has only a 150°F temperature limit.

Thanks Rich,

I just researched this stuff. If my copper tubing lasts this season, I'll install the PEX next winter. Looks easy enough and will outlast the boat. (I fear too much of what I'm sinking into this ol gal will out live her)

Dave

 

[lancelot9898]

While I think you are referring to the hose coming out of your hot water heater to your sinks, I thought you might be referring to the hose coming from your engine to the heat exchanger in your hot water heater. I'm using heater hose from an auto parts store for that with no problem. It's been a number of years(probably 10) since I replaced it and that is one thing I need to do this spring.

 

[overbored]

If you need higher temp tubing for potable water use PVDF tubing it is rated for 212F. Kynar is a brand name and a little expensive but will last forever. silicone hose is rated to 350F but very expensive at $15 a foot for 1/2"