Leaky Hot Water Tank

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Captain Kirk
Posts: 35
Joined: Wed Jun 08, 2016 12:05 am

Leaky Hot Water Tank

Post by Captain Kirk » Tue Jun 18, 2019 2:14 pm

Has anyone had to replace the HWT?

After checking all the connections on the front of the tank ( they are all dry, no leaks) I determined the leak was coming from underneath the tank itself. Its about 1/2 gal per day only if the water pressure switch is on, OR if the HWT is full of hot water, ie) plugged into shore power and switched on at the AC panel. Hot water will pressurize the tank I suppose.

Its a much smaller amount of water when these two conditions are not met.

I see the Seaward is widely available on Amazon etc, but wondering if anyone has experience with Kuuma or Camco units which look to be identical to the Seaward but are available at a much lower price. Kuuma is a Finnish product and I believe Camco is from Canada.

Also I see there is a blue hose connected to the pressure relief valve that trails down underneath all the other stuff in that area. I assume it is directed to the bilge somehow but i cant trace it to the bilge. Anyone know where it might come out, I want to monitor it to see if the relief valve is also a source of the water in the bilge.

Sorry for the lengthy post. Hoping somebody can enlighten me.
Kirk & Leah McCullough
#031
Sand Dollar

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scott.monroe
Posts: 11
Joined: Fri Mar 15, 2019 5:13 am

Re: Leaky Hot Water Tank

Post by scott.monroe » Wed Jun 19, 2019 3:56 pm

Oh my yes! I had a pin hole leak in the weld of the tank and it was dripping enough that it needed to go.

It was an exercise in square pegs in round holes! I opted to replace the exact model, purchased it from Defender,

https://www.defender.com/product.jsp?na ... d=15338419

Thought it was going to be an easy swap till I realized the water heater as assembled will NOT fit through the hatch way in lazarette!. Yep, the sheet metal casing is too big to fit through, grr. Solution was to dissemble the metal case to get to the pig shaped water heater. That will fit through the hatch way. But it gets better. To get the old hot water heater out you have to dissemble the housing to the hot water heater below deck and pass it in peaces up through the hatch. The boat was indeed built around the water heater. Then pass all the new peaces back through the hatch and re-assemble all over again. The good thing is that at this point you have now disassembled the water heater two times, and thus re-assembling it below deck can be done blind folded!
I was able to re-use the existing plumbing and A/C wiring so that wasn't too difficult to deal with. The overflow hose does go into the bilge some how, I too could never find its end point but since I re-used it...
All said and done it took me two days to get it done. Hardest thing was figuring out that I had to take the water heater apart to begin with.
Good Luck!
Scott Monroe
C350 #409 / Southern Yankee
North Kingstown, RI

leigh weiss
Posts: 177
Joined: Mon Mar 05, 2012 7:32 pm

Re: Leaky Hot Water Tank

Post by leigh weiss » Wed Jun 19, 2019 6:04 pm

Just replaced my temp/pressure relief valve that has the "blue hose" that drains to the bilge.
I found a replacement on ebay for about $12 Look for a 1/2" T/P relief valve from Camco i believe.
I removed the blue hose from the valve and saw that it was weeping after I tried popping the valve a few times. It never stopped weeping.
A quick fix that did not coat much. Unlike other boat projects.
I did not have water under the heater, just in the bilge.
Leigh and Donna Weiss
Brisa #155
Georgetown, MD. USA

Triumph
Posts: 236
Joined: Thu Nov 03, 2005 7:34 am
Location: Tampa, Fl

Re: Leaky Hot Water Tank

Post by Triumph » Thu Jun 20, 2019 6:07 am

I have very often criticized Catalina for using an 11 gallon water heater tank. It's simply too big and unnecessary for cruising in my opinion. For cruising, I installed a two gallon hot water tank under the galley sink. It is good for two showers. Or one shower and the dishes. I believe a 4-6 gallon water heater would be fine for our boats.

We do not run our main engine to charge batteries when out cruising. We therefore have to find a way to heat water. It takes a lot of "energy" or power to heat up 11 gallons verses 2 gallons. When you are out cruising for months at a time, energy and water need to be conserved.

We also use a sun shower to heat up hot water. I lay it on the deck above the head and run an extended hose down into the shower for my wife. I bath off the stern. It can get so hot we 've had to cover it to cool it down some!

When mine goes out I'm installing something a lot smaller.

Bill Cullen
s/v TRIUMPH
www.thebookofsail.com

Captain Kirk
Posts: 35
Joined: Wed Jun 08, 2016 12:05 am

Re: Leaky Hot Water Tank

Post by Captain Kirk » Wed Nov 06, 2019 4:04 pm

Getting back onto this topic after a good summer of cruising, 11 weeks on the boat, 8 of them continuous in July and August.

The water heater continued to leak through the summer but we managed it by turning off the water pump when not being used, to keep losses to a minimum. The bilge pump came on every day to discharge about 1/2 gal of leaked water. The water drips out from underneath the tank.

Now I'm once again looking to replace it and I agree with Bill Cullen who suggests the 11 gal tank is too big. The way we cruise we rarely plug into shore power even when we do go dockside and we anchor out more than we go dockside. We don't need to run the engine for the batteries as the solar panels keep the batteries topped up, so that leaves the Wabasto heater for making hot water when not motoring (along with a solar shower bag above the head and piped into the shower stall).

But it takes too long to get 11 gallons hot and we tend to use only 1-2 gals at a time for a shower or dishes etc and the remaining 9 gals are cold/lukewarm just a few hours later.

So long story short I've decided to go with a 5 gal Isotherm/Isotemp heater. its small enough to fit through the hatch and comes with a mixing valve that keeps the temperature leaving the tank at a slightly lower temp than water inside the tank, an anti-scald feature that extends the amount of hot water you can get at the faucets.

Does anyone else have the Isotemp? I'm looking for the best price supplier - are any suggestions from the group?

Thanks for the feedback from everyone.

PS, since i don't easily fit into the area where the tank is, I think I'll need to hire somebody to remove and replace it.
Kirk & Leah McCullough
#031
Sand Dollar

Interlude35
Posts: 32
Joined: Wed Mar 18, 2015 7:44 pm

Re: Leaky Hot Water Tank

Post by Interlude35 » Fri Nov 08, 2019 1:55 pm

HI Kirk - I replaced the original hot water heater(HWH) with an Isotemp 8 gallon plastic covered HWH that has the Thermostat mixer valve from Defender. I missed the annual sale but think there was a very good discount. The tank fits nicely into the location and has worked well. It has been in the boat for two seasons. There were several items: (1) The Isotemp HWH is round so I eliminated the storage shelf that was mounted on top of the old box HWH. This allows much better access to the HWH and refrigeration compressor.(2) I needed to install a GFI outlet as the Isotemp HWH has a plug and the old HWH was hard wired (3) One mistake was using the teflon tape for all pipe fittings instead of pipe dope. I had one fitting with a very minor leak. (4) I installed the fittings on the Isotemp HWH before placing it into the boat. I only had to install the hoses when the HWH was secured in place (5) The unit has A low 750 watt power drain so if you have an inverter and large battery capacity it may be possible to heat with electrical power when at sea. It seems to heat well from the engine as well. Hope this is helps.

John & Marilyn Ferguson
2005 Interlude
New London, Ct

Captain Kirk
Posts: 35
Joined: Wed Jun 08, 2016 12:05 am

Re: Leaky Hot Water Tank

Post by Captain Kirk » Sat Nov 09, 2019 6:41 pm

Hi John
Thanks very much for the input! All 5 of your items were very helpful. Good to know you are happy with your Isotemp. Did you need to disassemble the 11 gal tank in order to get it out through the hatch.

I dont mind losing the storage shelf but I might look into some other way to mount it, maybe reduce its size to give better access to the fridge and heater.

I like your idea on using the inverter to heat water electrically without shore power. We will get the 750W version too, since we do have a 450 Ahr golf cart house bank along with an over sized starting battery, solar panels etc. We do need to up-size the 1000W inverter though which is something that was already on my list.

Do you happen to know when Defender has its annual sale.
Kirk & Leah McCullough
#031
Sand Dollar

Triumph
Posts: 236
Joined: Thu Nov 03, 2005 7:34 am
Location: Tampa, Fl

Re: Leaky Hot Water Tank

Post by Triumph » Sun Nov 10, 2019 7:46 am

With regard to your thoughts on heating up the 8 gallons with the battery house bank through the inverter. I have a 2 gallon tank, a 2500 watt inverter, and the wattage of the heating element is 1200 watts. It takes eleven minutes to heat up the 2 gallon tank using the inverter. I believe it uses about 40 amp hours out of our 425 amp hour battery bank.
If our Honda generator is set up, we use it instead. It too takes 11 minutes.

Bill
TRIUMPH

wolfe10
Posts: 363
Joined: Mon Dec 11, 2006 2:58 pm
Location: League City, Texas

Re: Leaky Hot Water Tank

Post by wolfe10 » Sun Nov 10, 2019 9:42 am

I agree.

Unless you have a generator or are motoring all day, using an inverter to power a water heater heating element is not practical.

Said another way, unless you have a generator, I would only consider water heaters based on an engine heat exchanger loop.

And size/capacity really depends on YOUR hot water needs/desires. Have spent sufficient months "on hook" that we can get by with much less than OE capacity.
Brett Wolfe
C350 #180
"Vindaloo"
League City, TX

Captain Kirk
Posts: 35
Joined: Wed Jun 08, 2016 12:05 am

Re: Leaky Hot Water Tank

Post by Captain Kirk » Sun Nov 10, 2019 3:07 pm

Bill

Thanks for the background info on your setup. It gives me food for thought. Here's what I'm thinking when I compare my proposed system to yours.

1. 40 Ahrs to heat 2 gal should equate to 100 Ahrs to heat my 5 gal tank.
2. 11 min to heat 2 gal X (1200/750w) X (5/2gal) = 44 minutes to heat 5gal with a 750W element.

Question: what is current draw from your battery bank to the inverter? Wondering about wire size to feed the inverter from the battery.

Thoughts:
We normally only use 85 Ahrs/day, so adding another 100 to that seems to be excessive, however we can make 100Ahrs/day with the solar panels and we do motor short distances between anchorages so could use the inverter while motoring to augment the engine heat while charging the battery.
We can also use our hydronic diesel heater which draws 5 Amps and should take 1 hour to heat 5 gal so 5Ahrs. It currently takes 2.5hrs to heat 11 gal with the existing tank.
In general it think using the inverter on an as needed basis could be a good option for us when used in combination with the other methods we already have.
Thanks again.
Kirk & Leah McCullough
#031
Sand Dollar

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