What is this thing on my water heater?

[DBG8492]

I started working on my freshwater system this weekend, and after installing a new in-line filter system and finding out my pump was leaking (replacement ordered), I moved on to testing the hot water heater.

The only label I can see on it is "Force 10," but I know they make heaters branded by many other "manufacturers" so I'm betting they're all pretty much identical. It's the 11 gallon model - that sticker was the only one really completely intact...

It doesn't power up when the breaker is thrown - I haven't started troubleshooting that yet because I wanted to take some pictures and ask this question before I do.

On the hot water outlet, there is a T fitting that goes to two different outlets - one feeds the aft end (probably the head/shower) and the other feeds forward where I'm sure it goes to the galley and forward head.

*Behind* that T is another branch with some type of aluminum cylinder that has two outlets. The previous owner ran a small piece of hose between these two outlets. You can see it in the pic below although where the hose attaches to the bottom, it looks like it's attaching to the outlet of the T fitting - it isn't. It comes out of the aluminum tube horizontally on the aft side, then goes right back into the bottom of that tube vertically.

Anyone know what this is?

 

[DBG8492]

Found it!

It's a "Temperature Compensating Valve"

From this link:

"The other method utilizes a component known as a temperature compensation valve or TCV, which is plumbed, externally, to the water heater's coolant heat exchanger while sensing output water temperature. This product takes a slightly different approach in that it controls the amount of coolant running through the water heater in such a way that it maintains a water output temperature of about 140°F. These are offered with water heaters, also as an option, manufactured by Kuuma Products (Formerly Force
10)" - See pic below from the site

However, I see it, and I see the picture of it plumbed, but I'm still unsure of where it should go. From what it says above, It would appear to me that the coolant source from the engine should be plumbed through it, and it will "adjust the amount of coolant running through the water heater," - but wouldn't that restrict coolant flow going back to the engine as well? That doesn't sound like the best plan.

Wouldn't a mixing valve do the same thing with less risk?

 

[Jeff F]

There shouldn't be any risk to the engine, because typically the HW loop is in parallel so no through flow is necessary for cooling.

A mixing valve gives a bit more effective HW capacity because of higher temperatures, but otherwise either approach should work.

 

[DBG8492]

There shouldn't be any risk to the engine, because typically the HW loop is in parallel so no through flow is necessary for cooling.

A mixing valve gives a bit more effective HW capacity because of higher temperatures, but otherwise either approach should work.

Thanks.

Yeah - I think I will remove that when I replace the water heater and swap it out for a mixing valve.

I wouldn't even be fooling with this one now, but the admiral would like to be able to shower without having to walk a 200-yard round trip. And having hot water to wash and rinse dishes would be nice.

Going to be a few months before we buy and install a new one - so here I am.

 

[Delta Riverat]

That's a serious hose kink you got there, don't think much is getting through.

Yeah, with an engine coolant heat exchanger, the hot water tanks can get to 170F, serious scald. So you want a mixing valve to bleed in cold to keep it not so dangerous.

 

[Pete Meisinger]

Doesn't matter what it is. It isn't going to work properly with that kink in it.

pwete

 

[SeaDogAK]

It looks to me like someone disconnected the TCV from whatever it’s supposed to connect to, and just connected its two outlets to each other to seal it off. So it doesn’t seem like it’s doing anything at all. If that’s the case, I don’t suppose the kink matters.

Are the coolant lines that are supposed to heat the water connected?

 

[DBG8492]

It looks to me like someone disconnected the TCV from whatever it’s supposed to connect to, and just connected its two outlets to each other to seal it off. So it doesn’t seem like it’s doing anything at all. If that’s the case, I don’t suppose the kink matters.

Are the coolant lines that are supposed to heat the water connected?

I think you're right. It doesn't matter if anything is supposed to pass through it - the hose effectively acts as a plug on both ends so the kink doesn't matter.

Yes, the coolant lines to the engine are connected at both ends but that doesn't matter right now as we're on the hard. As a result, I will only be heating the water with AC power for the next couple of months. There will be a new heater and all new fresh water lines installed before we're back in the water.

So, for now, I'm good with it being looped, as it doesn't affect anything else.

 

[SeaDogAK]

Stupid question but I assume you located the reset button on the heater and tried that. If that doesn’t help I’m guessing someone ran it dry and burned out the element at some point.

 

[DBG8492]

Stupid question but I assume you located the reset button on the heater and tried that. If that doesn’t help I’m guessing someone ran it dry and burned out the element at some point.

Yeah, that was the first thing I checked - low-hanging fruit and all. Going to check the thermostat and element this afternoon. Just got caught up in other stuff over the weekend and didn't get to it.

And a burned-out element is the same thing I assumed, given that the boat sat for nearly two years after the PO's death without anyone touching it. There wasn't any water in the tanks when we took possession and some interesting stuff came out of the faucets when we did the initial clean-out/shock.

With the new filter system, I will use it for dishes and showering, but I still won't drink it until all the parts are replaced.

 

[Bacchus]

If you are troubleshooting and find either element, T Stat or over temp switches are bad you might consider replacing all 3 or at least T Stat & O temp. None are very expensive and you would start off with a known good system. If you WH is like many not the easiest place to work and above avoids a redo if any addnl components are compromised.

 

[DBG8492]

If you are troubleshooting and find either element, T Stat or over temp switches are bad you might consider replacing all 3 or at least T Stat & O temp. None are very expensive and you would start off with a known good system. If you WH is like many not the easiest place to work and above avoids a redo if any addnl components are compromised.

It's in a terrible place to have to work on it. It sits in the farthest aft starboard corner of the engine room, on a shelf that sits about eighteen inches above the rest of the deck. I feel that the boat was built around it honestly.

I plan to replace it, but I'm dreading the day I have to try to get to the mounting screws in the back...

 

[Sleeping Bear]

Those vinyl hoses get very soft when heated, I wouldn't use them on hot water.

 

[Mako]

… with an engine coolant heat exchanger, the hot water tanks can get to 170F, serious scald. So you want a mixing valve to bleed in cold to keep it not so dangerous.

This is the preferred method. He will see a nearly 80% increase in his hot water capacity with a tank temperature of 170° versus 140°, assuming a typical shower temperature of about 105° and a freshwater tank of 60°.

Since he’s replacing that old heater anyway, might as well plan for this arrangement and perhaps upgrade to a tank of 12-20 gallons as well.

 

[Mischief Managed]

I highly recommend replacing all those hoses with silicone heater hose with plenty of slack when you replace the water heater. They are super flexible, last forever, and easy to work with even after years in place. By leaving lots of slack, you can reconfigure for a different size and brand water heater with ease in the future.

 

[SIBERNUT]

H W Heater.

If you have to winterize where you are, consider a RV type setup. 3 valves bypass the tank & you drain by pulling the anode. Saves maybe 12 gals of antifreeze

 

[CaptTom]

While you're in there, put a valve on the engine jacket water loop so you're not heating your engine along with the water.

 

[Mako]

Good idea @Tom, plus it allows you to preheat your engine when you do wish it to.

 

[DBG8492]

So, I started troubleshooting this today. I was able to test the 120 to the heater - and it's good.

The next step should be testing the far side of the safety switch, the thermostat, and the element. But the switch and thermostat connections are potted - the wires are encased in an epoxy disk. I tried to turn them a little, but they didn't move, and I didn't want to break them off, so I left them alone.

I looked up the parts online and the pics don't show that the connectors have anything on them.

Are those just some kind of covers? Do they come off?

 

[janice142]

And having hot water to wash and rinse dishes would be nice.

For your wife: Aboard Seaweed I simply nuke (microwave) a small bowl half full of water. Add water to adjust the temperature as needed. Finally add Dawn Platinum, then use the hot soapy water for the galley cleanup. Rinse the dishes/pans with tank water and I'm done. It's 30 seconds to heat my water and I'm all set.

Above, I was off grid, conserving water. For that much water 10 seconds would be plenty. I always add more water to what I have heated to adjust the temperature...

 

[DBG8492]

For your wife: Aboard Seaweed I simply nuke (microwave) a small bowl half full of water. Add water to adjust the temperature as needed. Finally add Dawn Platinum, then use the hot soapy water for the galley cleanup. Rinse the dishes/pans with tank water and I'm done. It's 30 seconds to heat my water and I'm all set.

Above, I was off grid, conserving water. For that much water 10 seconds would be plenty. I always add more water to what I have heated to adjust the temperature...

That's basically what we do now except we don't have a microwave - we use the stove to heat the water, use that to wash, and then rinse with cold tank water. We only have one small sink, so it's easier that way. The only thing that would change if we had hot water on demand would be filling a pot with hot water, use that to wash, and then rinse with hot water from the tank.

We both agree that rinsing with hot water is better for the removal of soap and any residual fat - we only cook with butter, beef tallow, lard, or bacon drippings so it can be a challenge.