Water Heater Leak

Feb 16, 2012
198
Hunter 45 CC Alamitos Bay, Long Beach
I have a 2005 Hunter 45 CC, with a 11 gallon Force10 Water Heater, (now known as Kuma Water Heaters). The original Pressure Relief Valve was leaking (10 years old) so I replaced it with a new one. Now there is a small leak coming from somewhere that I cannot see or access, without disconnecting all of the hoses, draining and removing the water heater. However it only leaks when I have the water pump turned on. It appears to be coming from the underside of the water heater. The water heater also has a Watts Thermostatic mixing valve. Anyone have any ideas on the source of the leak, and why it only occurs when the water pump is on?
Thanks, Jeff
 

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Aug 26, 2007
268
Hunter 41DS Ventura, California
Hi Jeff,
It leaks with the pump on because it's a pressurized system. When the pump is off the pressure bleeds off.
Sounds like you will have to pull the tank to find the leak. Look for evidence like calcium deposits unless you can remove it without disconnecting.
Mine had an internal leak (9 yrs old) so had to replace. Good luck.
 
Sep 26, 2008
690
Hunter 340 0 Wickford, RI
I had the same situation on my 2000 340 at 12 years old. I have some pictures in my albums of the Water Heater Replacement. You can see the seam at the bottom of the tank (but not the pinhole) where it was leaking. Being that yours leaks only under pressure may be the source is at the top of the tank. Either way, it's probably going to have to be replaced. Not a hard job to do, just confining spaces. I've posted a couple of pictures here but the rest are in my albums. If you have any questions feel free to ask. Hope this helps.
 
Feb 26, 2004
22,979
Catalina 34 224 Maple Bay, BC, Canada
The Kuuma is the bottom of the line. If you replace it, get a Seaward. Life expectancy is twice the Kuuma. Of course, there are better ones, like Isotherm or Isotemp, I always forget the right name, but the shapes are different and many times hard to fit.

Impossible to help with leaks, smells and wiring with only pictures and no wiring diagrams. :) Just the nature of the internet.

Good luck. I replaced our heater in 2013 after 15 years with one that had just replaced a 12 year old one. Seawards.
 
May 24, 2004
7,164
CC 30 South Florida
If the water heater is 10 years old it is likely time to replace. Once they spurt a leak there is a likelihood that other leaks may follow in a short time. Just the thought of the hassle of having to remove and reinstall the water heater every so often will have me running to the chandlery for a new one.
 
Feb 16, 2012
198
Hunter 45 CC Alamitos Bay, Long Beach
The Kuuma is the bottom of the line. If you replace it, get a Seaward. Life expectancy is twice the Kuuma. Of course, there are better ones, like Isotherm or Isotemp, I always forget the right name, but the shapes are different and many times hard to fit.

Impossible to help with leaks, smells and wiring with only pictures and no wiring diagrams. :) Just the nature of the internet.

Good luck. I replaced our heater in 2013 after 15 years with one that had just replaced a 12 year old one. Seawards.
Thanks for the info on the Kuma vs. Seaward. When I bought our boat new, the water heater came with the Watts Thermostatic Mixing Valve. I have noticed that the water heaters I have looked at on line, and at this website, do not have the TMV's included. My question is do I need one?
Jeff
 
Oct 2, 2008
3,810
Pearson/ 530 Strafford, NH
A
Thanks for the info on the Kuma vs. Seaward. When I bought our boat new, the water heater came with the Watts Thermostatic Mixing Valve. I have noticed that the water heaters I have looked at on line, and at this website, do not have the TMV's included. My question is do I need one?
Jeff
After motoring all day the water in the tank is about 180 degrees. The mixing valve drops ours to a nice 95 degrees for showers. The 5 gallons will give us warm water for three days if used prudently.

All U Get
 
Oct 30, 2011
542
klidescope 30t norfolk
Yes and no. The mixing elbow keeps the hot water temperature lower more manageable on electric it only heats water to something like 180 deg. But when running engine usually in warmer water the heat exchanger heats it to almost 225 deg. That's hot
 
Jul 7, 2004
8,480
Hunter 30T Cheney, KS
Crazy thought, but has anyone insulated thier tank? Anything to gain by doing it?
 
Jan 7, 2011
5,442
Oday 322 East Chicago, IN
I am sure they are insulated under the sheet metal outer cover. Much like a household water heater.

Greg
 
Jul 7, 2004
8,480
Hunter 30T Cheney, KS
And like household heaters there are exterior jackets to be had to supplememt the inadequate tank insulation. They are used for long storage however.
 

MitchM

.
Jan 20, 2005
1,031
Nauticat 321 pilothouse 32 Erie PA
we had a brand new isotemp 6 gallon unit which was manufacturer - installed on the boat. it had an external mixing valve. (since all of the head sink and galley sink taps had their own mixing valves at the fixture, we kept the water in the tank at maximum temperature. that way we conserved hot water.) the Isotemp is a sturdy cylindrical stainless steel tank, 4 gal or 6 gal with an elliptical stainless steel access plate held on by huge bolts , and made watertight by a $65 gasket. (they also make square ones.) it is a very sturdy piece of equipment -- except for design of the retaining gasket. we keep the electric to the hot water tank off except when we are on the boat and connected to shore power. one cold week end, the $65 gasket unfortunately, started a very slow leak under pressure while the tank was on. the 'emergency' hi - temp shut off thermostat simultaneously malfunctioned, so the electric did not cut off. the temp skyrocketed and warped the elliptical plate causing a very noticeable leak. Rx: a new heater , replacing the old at age 10 years. i found it interesting that the manufacturer's instructions did not mention the gasket or suggest to replace the gasket each 3 years. that would have prevented the leak. (as to the thermostat , i guess i should pull it and test it each year. but who knew ???) these units are warranted for 5 years. using my credit card (AARP) that extends double any warranty gave me 10 years for $560. and it is an easy install.
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,746
CAL 35 Cruiser #21 moored EVERETT WA
I replaced my 25 year old heater with a Quick BXS 25L Square Water Heater 1200W. Installed easily, once I got the hose adapters to make the connections BSP to NTP. Great insulation in side means the water stays hot over night between engine run times. The temp mixer valve is not included.
 
Apr 8, 2011
772
Hunter 40 Deale, MD
I replaced my 25 year old heater with a Quick BXS 25L Square Water Heater 1200W. Installed easily, once I got the hose adapters to make the connections BSP to NTP. Great insulation in side means the water stays hot over night between engine run times. The temp mixer valve is not included.
I realize this is an old post - which is exactly why I'm interested in your thoughts regarding the long term use of the Quick water heater. I've read mixed reviews of them over time, specifically regarding poor welds and subsequent leaks. I'd be very interested to hear your experience as I'm considering a Quick cylindrical water heater for my boat.

Thanks in advance!
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,746
CAL 35 Cruiser #21 moored EVERETT WA
I have had it in the boat since I posted that thread. It is still performing. You'll have to give last year a pass as the boat went no where.

The only issue I had at the beginning was getting the proper nipples to install the hoses. It was a thread type issue. The ones packaged with the heater were wrong. You need to use pipe dope on the threads of the nipple that goes into the water heater or it will leak. Once installed I have been pleased. The reasons I selected it were
  • Insulated unit. Water stays hot 24 hours.
  • Size fits space in boat
  • Twin source heat for water... AC or Engine.
  • In the marina AC heating of water is quick
 
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Apr 5, 2009
3,072
Catalina '88 C30 tr/bs Oak Harbor, WA
Yes and no. The mixing elbow keeps the hot water temperature lower more manageable on electric it only heats water to something like 180 deg. But when running engine usually in warmer water the heat exchanger heats it to almost 225 deg. That's hot
The idea is correct, but the temperatures are off. the electric heating element has a thermostat that is adjustable from 110º to 170º and is typically set to 140º from the factory because temperatures greater than that are considered to be scalding. The engine coolant heat exchanger will heat the water to the same temperature as the engine which should not be more than 180º if the cooling system is working properly.

The tempering valve is there to reduce the 180º water down to 140º or below by adding some cold water to the hot to lower the temperature.
 
Apr 8, 2011
772
Hunter 40 Deale, MD
I have had it in the boat since I posted that thread. It is still performing. You'll have to give last year a pass as the boat went no where.

The only issue I had at the beginning was getting the proper nipples to install the hoses. It was a thread type issue. The ones packaged with the heater were wrong. You need to use pipe dope on the threads of the nipple that goes into the water heater or it will leak. Once installed I have been pleased. The reasons I selected it were
  • Insulated unit. Water stays hot 24 hours.
  • Size fits space in boat
  • Twin source heat for water... AC or Engine.
  • In the marina AC heating of water is quick
Thanks much!! I've been looking to upgrade my factory 5 gallon water heater to an 11 gallon to make the wife happy, but so far haven't been able to find anything to fit in the original spot under the salon settee, and relocating isn't worth the effort. Even my marine plumbing guy hasn't been able to find anything with the right dimensions to fit in there. The Quick 40l might just be small enough if mounted to the back of the settee, and resting on the floor so the mounts are there to stabilize, and not take the weight (if that makes sense).

I had given up hope of finding a tank that would fit, when by chance I noticed another Marlow Hunter 40 for sale listed an 11 gallon hot water tank. I wrote to the broker, and to my great surprise not only did he respond - and quickly - but provided a photo of the installation. He didn't know the brand of tank, but after some looking close at the photo and digging online I think its a Quick 40l stainless, whose dimensions might just fit with some creative installation. I'll be checking dimensions this weekend. Here's the photo of the install where you can see the brackets mounted vertically, and the tank resting on the bottom of the settee plywood.:
1694014585725.png
 
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