Hot water from engine

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On my old hot water heater....the mixing valve was actually connected to both...as the water heater got too hot, it started shutting down the flow from the engine coolant lines.

I think though the OP said there were no mixing valves.
 
psneeld said:
On my old hot water heater....the mixing valve was actually connected to both...as the water heater got too hot, it started shutting down the flow from the engine coolant lines.

I think though the OP said there were no mixing valves.
Click to expand...
I bet it was not interconnected between antifreeze side and potable side.

Looking at My heater, Seaward Water Heaters
It shows an 'option' of having a tempering valve installed. I do believe that now that I know about it, I will install one. I am constantly worried the GrandKids will scald themselves the water is SO hot coming out of the faucets.

Looking at these lets me see how easy they are installed. http://www.isotherm-parts.com/index...d=1926&zenid=aa3407e05c9a03f2ba187a0ac0fe111d

Using the stainless reinforced poly hoses with the crimped on connectors seems too easy to be true. I will have to open up the boat fund next week.
 
cappy208 said:
I bet it was not interconnected between antifreeze side and potable side.

Looking at My heater, Seaward Water Heaters
It shows an 'option' of having a tempering valve installed. I do believe that now that I know about it, I will install one. I am constantly worried the GrandKids will scald themselves the water is SO hot coming out of the faucets.

Looking at these lets me see how easy they are installed. http://www.isotherm-parts.com/index...d=1926&zenid=aa3407e05c9a03f2ba187a0ac0fe111d

Using the stainless reinforced poly hoses with the crimped on connectors seems too easy to be true. I will have to open up the boat fund next week.
Click to expand...
Obviously not ibterconnected...but both sides did enter the valve, and it was screwed into the coolant inlet of the heater.
 
Looking for such a valve. Having trouble finding one. Recall any names off it?
 
Sorry....it was older and I didn't keep it when switching water heaters.
 
cappy208 said:
Looking for such a valve. Having trouble finding one. Recall any names off it?
Click to expand...

Just look for "thermostatic mixing valve" on the Home Depot web site. They have them now with SharkBite connections so you can hook up to PEX, which is what I'm slowly converting everything to.

Just to be clear, you don't want a "tempering valve" unless it says it's thermostatically controlled. Otherwise you just get a pre-set mixture of hot and cold. Since your "hot" isn't consistent, the output temperature won't be consistent. The thermostat is there to mix the correct amounts to give you the output temperature you want.
 
"uses an antifreeze loop w/ no mixing valve".

Dont be so sure .

Some brands of HW heaters "temper" the water simply by shutting off or slowing down the engine coolant.

IF there is an "item" where the engine water comes out of the HW unit , you have one.

Remove it and the domestic water will get to engine temperature.

Dangerous for kids aboard.
 
FF said:
IF there is an "item" where the engine water comes out of the HW unit , you have one.

Remove it and the domestic water will get to engine temperature.

Dangerous for kids aboard.
Click to expand...


Might you have a pic of what this item looks like? Are they brand dependent? Or would an ordinary tempering valve work?

All I know is when my boat is running the water comes out of the faucet at 180. Way too hot. So you have seen these valves on both the engine side as well as the potable side?
 
The home depot temperature regulator is here:

Cash Acme Heatguard Tank Booster-24409 - The Home Depot

and it fits across the hot water and cold water ports of a water heater. All it does is temper the output temp by watering it down with cold water so the output is always at 120 degrees F, regardless of how much higher the tank temp gets. It also makes the hot water supply last longer if you have ladies aboard :)

Stu
 
I think the ABYC standards may have recently been updated to require thermostatic mixing valves. I should have installed one the first time I realized how hot engine heated hot water could be.
 
So, These valves all reside in the potable side, not on the engine water side. Seems to be different information than what was presented in some posts. I guess it really does't need throttling of the engine coolant in the HWT as much as the potable tempering.
 
If it make the hot water last longer, the inventor should get a Nobel.
 
There are two type of valves with the same concept but different operation.

A 'Tempering valve ' will attempt to modulate the water to a preset temperature.

Should it get hot water , but NO cold it will pass the hot.

An anti "Scald valve" will shut off the hot if it can not maintain the temperature.

Difference in price as well as operation. CAVIAT EMPTOR!

AS to weather the HW heater that is installed has an engine coolant slowing feature , google the mfg literature, there are many different units.
 
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