Marine Hot Water Tank

[FF]

There are bypass kits made for RV that are very inexpensive.

The hot & cold piping is joined , so not much pink goo, "drinkable antifreeze" is needed to winterize.

The HW heater is drained and needs no antifreeze.

In the spring flush the FW piping first then switch the bypass valves and your set to go.


Camco 35953 8" Supreme Permanent By-Pass Kit for 6 Gallon Tank - Lead Free

 

[Steve DAntonio]

If you want to retain heat in a water heater, add insulation around the heater, bottom, top and water lines. The stock insulation isn't great.

I use a 50 gallon house water heater. It sits on 2" foam with foam all around including the top. Both hot and cold lines are insulated, the cold for ten feet. It holds enough heat for daily showers and cooking for 2 days, 2 people (depending on how much water you use).

I love this idea, I have been adding insulation to marine and household water heaters for years. You don't really need any insulation on the bottom, the heat is leaving primarily through the top 2/3rds.

 

[sunchaser]

I replaced my Hot water tank a couple of years ago. The old one was a Torrid, and it lasted a long time, 20 years. This is the thread discussing possible repair.
https://www.trawlerforum.com/forums/s31/repair-torrid-20-gal-hot-water-tank-41870.html

They have excellent customer service and you should consider them given your location. They aren't available here in Australia. So I went with a Raritan. I regard it as a good brand also.

x2 on Torrid. We had one installed by a large yard a few years ago who does a few dozen tanks a year. Their preference is a glass lined Torrid. You can price check them against the SS Raritan. Be sure you're getting 316 SS as mentioned by CD, glass lined and avoid Al tanks like our failed after 8 years old Seaward.

 

[Steve DAntonio]

There are bypass kits made for RV that are very inexpensive.

The hot & cold piping is joined , so not much pink goo, "drinkable antifreeze" is needed to winterize.

The HW heater is drained and needs no antifreeze.

In the spring flush the FW piping first then switch the bypass valves and your set to go.


Camco 35953 8" Supreme Permanent By-Pass Kit for 6 Gallon Tank - Lead Free

Completely agreed, never run non-tox through water heaters and avoid using it in tanks as well, simply drain them, unless you are prepared to do a lot of flushing in the spring.

 

[Mako]

Wouldn’t it make more sense to attach a couple of simple fittings and blow the water out of all piping with compressed air, rather than use and then have to flush antifreeze?

 

[FF]

"Wouldn’t it make more sense to attach a couple of simple fittings and blow the water out of all piping with compressed air, rather than use and then have to flush antifreeze?"

Yes and No, If all the water was blown out it would work fine , BUT the nature of boats is sometimes complex piping that might not blow clear. Run the air for a day or two might work, but there is always the risk.

Remember to blow out the sink hand sprayer?

The Pink goo does work and at $3 or $4 a gallon is cheap insurance.

Just be sure to leave the system filled as it flushes out quickly , because if drained the goo will evaporate and leave the pink color , which is slow to reliquify , so the water is pink a long time.

 

[Steve DAntonio]

I've actually winterized hundreds of boats using compressed air, it was our winterization technique of choice for fresh water systems that had never had non-tox in them. The routine was, run inexpensive vodka (seriously, usually Popov) through them, then clear with compressed air. So, a combination of an anti-freeze and compressed air.

 

[Mako]

I've always been a proponent of using domestic appliances, pumps, etc., in my large boat. The big box stores will sell a 20 gallon water heater, single 1500 watt element, for about $350. That's great value and you could run it from an inverter.

My own boat had a 40 gallon and I think the twin elements were 4kW or larger. No way to run that off an inverter however.

 

[FF]

"My own boat had a 40 gallon and I think the twin elements were 4kW or larger. No way to run that off an inverter however."

Most hardware stores will have elements of greatly different power draw.

Most are the same thread pattern so switching will be no effort.

Yes a big HW heater takes up a bunch of space but if you think of of as your emergency water supply it begins to look smaller.

 

[Mako]

That's a good point. A standard 50 gallon WH is cheap to buy. The drain at the bottom becomes a great place to draw from for emergency water. Perhaps replace one element with a 1500W and leave the other as factory (say 4500W), perhaps wired separately to generator and to inverter.

So your engine provides a huge supply of hot water, heavily insulted to last days, then you can solar dump to the small element, or genset heat to the big one.

Any issues with this setup?