hot water tank mod ?

[Lanark Camper]

I did a mod to my sailboat hot water tank that might be useful in a trailer.

I installed a mixing valve to limit the temperature of the hot water. the water was heated off the diesel engine and became scalding hot after a couple of hours. For safety reasons I added a mixing valve that limited the max temp at the taps.
One additional benefit was it really extended the amount of hot water use from the 6 gal tank.
I am considering adding one to the trailer if its possible to turn up the temperature in the hot water tank. Is that feasible ?

Here is the mixing valve I used and found it worked well,
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Bob

[padlin]

Why is it different then just turning on the cold to mix with the hot at the faucet? I can see the safety benefit if you worry about such but why would it save hot water?

[Vermilye]

While there is no reason you can't add a mixing valve since many complain that the hot water is already too hot, I don't believe there are different temperature thermostats for the water heater.

[Brian B-P]

There is a variant of the Atwood 10-gallon water heaters (which they labelled "XT") which claims to have a larger effective capacity. What it really is, just as proposed in the original post, is a normal 10-gallon heater with a higher-temperature thermostat and with a mixing valve mounted right at the heater. The output of the mixing valve is about the temperature of a normal heater, with the valve mixing roughly 10 parts very hot water with 6 parts cold water to make 16 parts of normal "hot" water. I have one in a large trailer which we haven't used for a while; it seemed to generally work fine.

Since Dometic bought Atwood, these are still available, as Dometic XT Water Heaters, and they have them in both 10 gallon and 6 gallon (U.S. gallons, actual tank capacity) sizes.

This is fundamentally no different from just running the heater at a high temperature and mixing appropriately at the faucet, except that it is safer (avoids scalding) because the very hot water directly from the heater is not available at any faucet. The system does not save water; it makes more hot water available.

So if someone wants to do this, and they can use an Atwood/Dometic thermostat (keeping in mind that Escape water heaters are from Suburban), the higher-temperature thermostat and mixing valve are available as replacement or salvage parts.

[rotorbudd]

You might want to check the hot water temp. before you crank it up, if it can be adjusted
Ours is set so high you could brew coffee straight out of the tap!
I haven't found a way to adjust the temp BTW

[Lanark Camper]

It sounds like the hot water temperature is quite high but not adjustable on the 6 gal tanks.

I'll wait and see how our operates once we get the trailer. Then order the mixing valve if it seems like a good idea.

We found it safer and much quicker to adjust the water temp for dishes and showers, resulting in less hot water being used from the little tank. If I was in a camp ground with shore power its not an issue, but boon docking the only way to heat more water is to run a generator.

Bob

[gbaglo]

Originally Posted by Lanark Camper

but boon docking the only way to heat more water is to run a generator.

Bob

The water heater is propane, unless you order it "two-way" ( propane and AC )

[Lanark Camper]

Originally Posted by gbaglo

The water heater is propane, unless you order it "two-way" ( propane and AC )

HA! your right ! I'm still thinking like a sailor, we don't have the propane option for hot water on a boat.
thanks for straightening me out, Bob

[Viajante]

Originally Posted by Lanark Camper

It sounds like the hot water temperature is quite high but not adjustable on the 6 gal tanks

Bob

You are correct, the water temp is preset at about 130 degrees and is not adjustable. The mixing valve sounds like a good idea. Mixing at the faucet wastes water.

I have seen ads for adjustable thermostat retrofits, but that would defeat the purpose of extending the volume of hot water by mixing very hot with cooler.

[Chotch]

Originally Posted by Lanark Camper

I did a mod to my sailboat hot water tank that might be useful in a trailer.

I installed a mixing valve to limit the temperature of the hot water. the water was heated off the diesel engine and became scalding hot after a couple of hours. For safety reasons I added a mixing valve that limited the max temp at the taps.
One additional benefit was it really extended the amount of hot water use from the 6 gal tank.
I am considering adding one to the trailer if its possible to turn up the temperature in the hot water tank. Is that feasible ?

Here is the mixing valve I used and found it worked well,
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Bob

🤔 make it too hot just to make colder??
How does that save anything? First off you use more propane to get it up to temp then it will require more to maintain the higher temp. What’s the point?

[rubicon327]

From Suburban manual...

[Ian and Sue]

Originally Posted by rubicon327

From Suburban manual...

The water heater in my scamp was a 6 gal...don't remember who made it...and it had a little adjuster bar for temp. Too bad they don't make them that way anymore.

[rubicon327]

Originally Posted by Ian and Sue

The water heater in my scamp was a 6 gal...don't remember who made it...and it had a little adjuster bar for temp. Too bad they don't make them that way anymore.

Maybe an old Atwood. There were models that were adjustable from 110-150F.

[Brian B-P]

Originally Posted by Chotch

🤔 make it too hot just to make colder??
How does that save anything?
...
What’s the point?

It doesn't "save" anything; it makes more hot water available:

Originally Posted by Brian B-P

There is a variant of the Atwood 10-gallon water heaters (which they labelled "XT") which claims to have a larger effective capacity. What it really is, just as proposed in the original post, is a normal 10-gallon heater with a higher-temperature thermostat and with a mixing valve mounted right at the heater. The output of the mixing valve is about the temperature of a normal heater, with the valve mixing roughly 10 parts very hot water with 6 parts cold water to make 16 parts of normal "hot" water.
...
The system does not save water; it makes more hot water available.

Of course the water still comes from somewhere - all the water that you use comes from the tank or the city water connection. Use more water and, well, you use more water.

Originally Posted by Chotch

First off you use more propane to get it up to temp then it will require more to maintain the higher temp.

True, the higher holding temperature will mean more heat loss, causing more propane consumption; also, the efficiency of the heater drops as the heated water temperature gets closer to the exhaust temperature. On the other hand, other than these inefficiencies, this scheme does not required any more energy heat the water; the total energy increase from cold water to heated water is the same, whether you heat all of the water just enough, or heat less water through a higher temperature difference.