• Welcome to this website/forum for people interested in the Morgan 38 Sailboat. Many of our members are 'owners' of Morgan 38s, but you don't need to be an owner to Register/Join.

Hot water heater.

Warren Holybee

Active Member
My hot water heater recently started leaking. If money were no object, I would probably replace it with a like kind Raritan. 40 years is a great service life even in a home. In a boat that is astonishing.

At nearly $1k, it's just too much money. I looked at older threads and see several people have installed the isotemps, and some have even squeezed in bigger tanks. I'm inclined to go smaller. The space isn't really shaped right for a sideways tank, and while I might be able to shoehorn in a big tank, id rater have a clean install with more space around the tank. The 6 gallon, when super hot from the engine, was enough for 3 showers. I think I could get 2 showers out of the isotemp spa 15, 4 gallon, and also the smaller capacity would heat quicker. I'd probably opt for the optional 1500w element for fast heating.

I also want to rework the pluming. I don't like the OEM install with so many plastic tee connectors on the tank inlet and outlets, and also want to add shutoff valves to the hot water tank, and to add a decent water filter after the water pump. Maybe also size up the pipes to the shower for more flow. 3/8" ID is tiny.

Anyone want to share pictures under the sink showing what has been done with the pluming?
 

Travis

Member
My hot water heater recently started leaking. If money were no object, I would probably replace it with a like kind Raritan. 40 years is a great service life even in a home. In a boat that is astonishing.

At nearly $1k, it's just too much money. I looked at older threads and see several people have installed the isotemps, and some have even squeezed in bigger tanks. I'm inclined to go smaller. The space isn't really shaped right for a sideways tank, and while I might be able to shoehorn in a big tank, id rater have a clean install with more space around the tank. The 6 gallon, when super hot from the engine, was enough for 3 showers. I think I could get 2 showers out of the isotemp spa 15, 4 gallon, and also the smaller capacity would heat quicker. I'd probably opt for the optional 1500w element for fast heating.

I also want to rework the pluming. I don't like the OEM install with so many plastic tee connectors on the tank inlet and outlets, and also want to add shutoff valves to the hot water tank, and to add a decent water filter after the water pump. Maybe also size up the pipes to the shower for more flow. 3/8" ID is tiny.

Anyone want to share pictures under the sink showing what has been done with the pluming?
I will share a bit of my experience. I made the painful switch to PEX about a year and a half ago. I was somewhat limited by the local Home Depot stock so I had to make a few compromises and use adapters in the interest of getting it done in a reasonable amount of time. It is a lot of work upfront, hard on the hands, and the hardware is a little pricey, so I started with a simple layout but I’ve been slowly adding things. The ease at which you can do that makes it all worth it.

I went with a “hot and cold manfiold” design instead of the original “tee-style” That Morgan used.

When I built it I used the brass barbed variety of the pex fittings. Now If I’m feeling especially lazy about a modification, I buy the more expensive bronze sharkbite style fittings, which are almost too easy to be true.

A few changes I have made:
-Created a dedicated hot water manifold (pictured)
-Added or replaced a fair number of isolation valves for troubleshooting purposes
  1. valves at pump at inlet and outlet
  2. valves at hot water heater at inlet and outlet
  3. valves isolating head sink/shower hot and cold
  4. [-plan to add isolation valves to cockpit shower hot and cold]
-Added check valve at water heater inlet (pictured)
-Added drain valve to the hot water heater (pictured)
-Added pressure gauge (pictured)
-Added easier disconnects to water heater inlet and outlet
-Added a spring loaded pressure relief valve at the high point of the system, to manually remove air.

If I did it again, I would definitely use the plastic ring clamps instead of the stainless ones. The ones I have are fine but it’s very tough to remove them in-situ without fouling something else up. The new plastic expansion style ring clamps came out in force not long after I bought the $65 specialized crimper for the stainless ones. Oh well!
The plastic ring clamps are undeniably better for a marine environment in my opinion. Cheaper too I believe.

Finally, Pex is pretty rigid, so it’s tricky to avoid things being “a tiny bit too short”. I gave everything a little extra length figuring things would change over time. If a fitting or valve fails there should be plenty of slack to yield an extra inch or two of length toward a given fitting.

Putting it in was certainly type 2 fun, but it has been worth it from a maintenance perspective.

3E411E04-BA6E-49B5-A9A8-80A1337DD178.jpeg
E2294803-BF8B-46AB-83A6-A3DBE8BCD3E7.jpeg
 
Last edited:

rickdowe2

Richard Dowe
Hi Travis, when I built my house in 2008 a plumber let me use his pex expansion tool by Wirsbo. At that time it was the original developer of the pex system and the tool was 500 dollars. Recently I picked up a knockoff for 69 dollars. Like everything the fitting are little pricey but does make a good looking product when done. Rick
 

Travis

Member
Hi Travis, when I built my house in 2008 a plumber let me use his pex expansion tool by Wirsbo. At that time it was the original developer of the pex system and the tool was 500 dollars. Recently I picked up a knockoff for 69 dollars. Like everything the fitting are little pricey but does make a good looking product when done. Rick
Rick,
That is definitely a deal worth bragging about. It might sound silly, but before you mentioned it I hadn’t really thought about the expander as a compliment to the crimper. If I had to do another pex job on a boat $69 would be a no brainer. That tool would have made the the install easier and maybe a bit faster too. Maybe I’d just sell it at the end? In general but especially on one of the colder days I had to use a heat gun to warm some of the tubing up enough to insert some fittings. The positions I had to get into to gain leverage while managing a hot heat gun were probably something to behold. Almost a 2 person job without the expander really...

What brand is the knock off one you got?
 

Warren Holybee

Active Member
Well that was a PITA.

I ended up with the Raritan. Much more expensive than I wanted, but after hours of measuring and looking at dimensions, it seems to fit the shape and size of that area the best. And as nearly a direct replacement (After 40 years the design has changed a bit) made for a fairly simple and quick install. Mostly done, except that Home Depot delivered the wrong valves which I was going to insert in the heater hoses. So the heat exchanger isn't connected yet, but I otherwise have hot water again. They also delivered the wrong valve for what was to be a drain valve.

I didn't use PEX. If/When I replum the rest of the boat I will surely use it for that, but for under the sink with tight bends, reinforced clear PVC seemed best. I constructed a cold water manifold from brass parts, with a ball valve for a hot water shutoff. I kept the same hot water hot configuration, as I don't see a need for anything more complex for only 2 hot water outputs.

Breaking it into smaller jobs, the first day I built the cold water manifold, and plumed it in place to the old heater. This gave me a valve to disconnect the hot water heater, and still have cold water. The second day I tore out the old heater and shelf. Third day installed a new shelf and heater. As I mentioned, I still need to connect the heat exchanger after Home Depot corrects their mistake.

It heats water to shower hot in about 15-20 minutes, and the outside stays cool. It will be interesting to see how warm it gets when it is really hot from motoring all day. The old tank got very hot, and cooked food in the storage above it. The old tank had a steal enclosure, with fiberglass insulation. The new has a plastic enclosure, with foam insulation.

Excuse that the pictures posted all sideways. They don't look like that on my phone or on my PC.


wh1.jpgwh2.jpgwh3.jpgwh4.jpgwh5.jpgwh6.jpgwh7.jpg
 

royaltern

Bert Willett
Warren you need to check out the bus system in Portsmouth. I think it goes from close to you to home depot,Food Lion, and Target.
 

Travis

Member
Well that was a PITA.

I ended up with the Raritan. Much more expensive than I wanted, but after hours of measuring and looking at dimensions, it seems to fit the shape and size of that area the best. And as nearly a direct replacement (After 40 years the design has changed a bit) made for a fairly simple and quick install. Mostly done, except that Home Depot delivered the wrong valves which I was going to insert in the heater hoses. So the heat exchanger isn't connected yet, but I otherwise have hot water again. They also delivered the wrong valve for what was to be a drain valve.

I didn't use PEX. If/When I replum the rest of the boat I will surely use it for that, but for under the sink with tight bends, reinforced clear PVC seemed best. I constructed a cold water manifold from brass parts, with a ball valve for a hot water shutoff. I kept the same hot water hot configuration, as I don't see a need for anything more complex for only 2 hot water outputs.

Breaking it into smaller jobs, the first day I built the cold water manifold, and plumed it in place to the old heater. This gave me a valve to disconnect the hot water heater, and still have cold water. The second day I tore out the old heater and shelf. Third day installed a new shelf and heater. As I mentioned, I still need to connect the heat exchanger after Home Depot corrects their mistake.

It heats water to shower hot in about 15-20 minutes, and the outside stays cool. It will be interesting to see how warm it gets when it is really hot from motoring all day. The old tank got very hot, and cooked food in the storage above it. The old tank had a steal enclosure, with fiberglass insulation. The new has a plastic enclosure, with foam insulation.

Excuse that the pictures posted all sideways. They don't look like that on my phone or on my PC.


View attachment 8147View attachment 8148View attachment 8149View attachment 8150View attachment 8151View attachment 8152View attachment 8153
Warren,
That is a smart order of operations and lot of work for two days! Not easy to keep any boat project a single-weekend-project, even without delivery setbacks.

Similar to your situation, as things dragged out with our installation, it became apparent that extra valves were worth it - the main system can be pressurized while other portions are isolated and worked on.

Also the more I think about it the more I feel like it was a smart move to use the flexible tubing in the under sink area. As you allude to, some of the runs require multiple bends under the sink. They make “bend support brackets” but that’s just one more thing to buy, and once you have a few installed along a single run, things feel pretty...tight, like a flexed bow. And forget about moving it around! The vinyl solves pretty much all of those problems. Interesting.
 

rickdowe2

Richard Dowe
Hey Travis, sorry am late getting back to you. I have been working night shift for a while plus trying to get the boat in the water has left little time. Here is a picture af what I bought. RickIMG_1633.JPGIMG_1634.JPG
 

mpearson

Mark Pearson
Staff member
Hey Warren (or anyone) - I'm in the middle of re-plumbing our water heater now. The Raritan water heater instructions recommend some valving so that you can control how much of the engine hot water exchanges with the water heater. See drawing below. Zia didn't have that in the original plumbing and for sure, the water got super hot when motoring for a while.

It also seems to me that unless you are actively using hot water on the boat, even if you partially restrict the flow of the engine water, eventually the hot water heater will reach the same temperature as the engine water. Unless you are actively adjusting that mixing valve (#4) all the time (and we won't be).

It also costs about $100 for all the valving/fittings to do this. And we don't have a ton of space under there.

I'm thinking about leaving this off (engine water mixing valving). Does anyone have any thoughts or experience with this? Me & crew will just need to be aware that the hot water will be seriously hot after we motor. With our new plumbing, hopefully we will get rid of the big spurts of water which are a little troubling when they are scalding hot.

It seems like it would be better to turn the thermostat up on the water heater so that it would be more like the engine water temperature. And add a thermostatic mixing valve to blend some cold water into the hot water line before it goes to the user. Raritan also shows that kind of mixing valve in their instructions, but doesn't mention using that instead of the engine water mixer diagram shown below.

Any advice/comments are appreciated.

Thanks!
-Mark

1635518260643.png
 
Last edited:

Warren Holybee

Active Member
I think the referenced valve and pumping is to ensure adequate cooling of the engine, not for temperature control of the water heater. You would need to install some sort of thermostat valve for that. Yes, the water from engine heating gets REALLY hot. I installed a ball valve in the hose under the galley sink so I can turn it completely off, and only turn it on when I actually want hot water.

My engine (a Volvo) had provisions for connecting a hot water heater. One plug on the water heater, and another on the thermostat housing. I just replaced those with hose barbs and didn't do anything else special.
 

mpearson

Mark Pearson
Staff member
Warren - thanks for pointing that out. You're right - that valving is more for cooling the engine, although it doesn't seem that it would have a big (long term) effect on the engine unless someone was actively using hot water. I think I'll put a thermostatic mixing valve after the water heater. $85, because it would be nice to have somewhat consistent water temps.

So I understand you're leaving Virginia early next week and plan to be in San Fran next summer? Any more details on that plan, or are you just going to go with the flow? You must be busy with prep, but if you are so inclined, please post a little thread with your plans? And maybe you could periodically update with your status (and pictures!), unless you're already doing that on some other site.

It would be great inspiration to those of us who are still desk-bound more than we'd want.

Good luck on your journey!
-Mark
 
Last edited:

jimcleary

James M. Cleary
An alternative method of providing for hot water for showers and dishwashing plus cabin heat when it's cool, is an Espar Hydronic heating system. These are small diesel heaters that were originally designed for over the road trucks. Instead of the heat to heat the hot water coming from the engine, it comes from a separate burner (see photo). The 2 - 3/4" hoses run from the port cockpit locker to the main cabin where they connect to the hot water heater in the galley, then run to heaters in the main cabin and the V-bunk. When the system is running there are fans at the cabin heaters to push out cabin heat. If cabin heat isn't required, hot water is always being made. To have hot water for showers or dishwashing we turn the system on 15 minutes before we reach our destination and hot water is waiting. If we are anchored for a number of days we have hot water without running the engine. The Espar burner sips diesel fuel at at about 1/6 GPH. I've attached the schematic of the system and a photo of the burner ( 10" x 8" x 2-1/2") in the port locker.

Jim
 

Attachments

  • Dana-Espar Heating System.jpg
    Dana-Espar Heating System.jpg
    635.4 KB · Views: 18
  • 16-054 Dana-TBs & Espar 160210-10.jpg
    16-054 Dana-TBs & Espar 160210-10.jpg
    3 MB · Views: 18

struell

Stephen Ruell
A couple of thoughts of the Raritan installation from what I have experienced:
1. I replumbed similar to the discussion and had a hard time witht the threaded fittings. If you try to have the pipes go in a specific direction it is really hard to use threaded fittings. Ihave not been able to aim the pipe threaded fittings like I see in the previous photos, without getting leaks. I think there needs to be a swivel or hose in the tank connections so that the pipe thread on the water heater inlets and outlets can be tightened, When a pipe thread is tight you don't have control that an elbow or tee will be pointing in the right direction. I thought my Raritan was leaking and it turned out to be the fittings that I used could not be tightened. I changed to straight hose barb to MPT adapters on the water heater then attached automotive radiator rubber hoses - no more leaks. You can also use Sharkbite fittings since those swivel.
2. We don't have scalding problems in our experience. We let the engine heat that six gallons as hot as it will get. Just doesn't seem to be an issue. With only six gallons of hot water and 40 to 80 gallons of cold water we do not have a problem with scalding but adjust the temperature before getting into the flow. Cutting the temperature of the 6 gallons will mean you will run out of hot water a lot earlier. But I wouldn't send a small child in to take a shower without some supervision.
3. I took the heater out to replace it- don't know how old it is- but found that it had a lot of sediment in the bottom that needed to be flushed out. There is no low level drain on the unit so it traps sediment and the only way to clean seems to be to tip it on its side and connect a hose to flush it. Must have been at least a gallon of solids in there. After that I put it back in with the hose connections instead of rigid pipe connections and had no leaks. Returned the hot water heater I was going to replace it with and saved some bucks.
Steve
 
Top