Hot water heater test

[reedbr]

After de-winterizing this weekend, I noticed my fresh water pump cycling every 5 minutes with no spigots running.  After checking all the fresh water lines and checking clamps, I noticed drips from the bottom of the hot water heater right next to the batteries (MKII).  I removed the fresh water lines and connected the feed and return engine coolant lines together for a bypass, then removed the water heater.

The water heater is now in my basement and I have removed the cover and dried it out.  The tank itself looks to be in good condition, aluminum with no signs of corrosion.  I think it might be one of the fittings, but it only leaked under pressure.  Does anybody know of a good way to do a pressurized bench test of the hot water heater?  I was thinking of plumbing the fresh weater supply and return to a T fitting and with the last opening being a hookup to my garden hose.  I assume my home water pressure would closely mimic what the 12v freshwater pump is producing.  There is also a pressure relief valve and a drain valve, but plumbing a T to supply and return seemed easier.  Any other ideas?

[Jim Price]

I am not sure what brand you have but I have Seward 6 gal. tank on my 1991.  I experienced leaks at engine coolant fittings and rather than replace the whole system, I purchaced the internal tank (about $70) from Seward, purchaced new heating element from Home Dpot
(the other marine store)and reinstalled.  Absolutely no problems or leaks now.  Seward told me that if fittings were leaking, not a repair option but all parts can be replaced independently short of buying complete new system.

[Jim Rose]

Brian,

I also have a fresh water leak  coming from the water heater.  Last summer I only turned the pressure water on when I needed it.  It is not leaking from any of the fittings.  There is not a lot of space to remove the heater.  Did you remove the batteries for access?  The engine coolant lines running under the galley also look difficult to access.  How did you go about that?  Thanks for any comments.

[reedbr]

Jim-

I have hull 1365 and it was a little bit of a game to get the hot water heater out without removing the batteries and their trays.  However, it only took about 30 minutes and three knuckles.  Removing the batteries and trays would be the "right" way to do it, but those 4D's weigh a lot.  

To remove, first, I removed the 4 screws holding the front mounting tab down.  That made the unit loose in the locker.  Then I removed the freshwater lines in front and 110 wiring (kill shore power first) and slid the unit forward as far as possible.  Using a 5/16 nut driver, I reached behind the heater and loosened the engine coolant line clamps.  For orientation help, you can see one of the fittings from under the galley sink, and the second from behind the bottom galley drawer (just pull the drawer out).  Next I suckered a helper to twist and pull on the hoses from under the sink while I pried at them gently with a screwdriver from the locker until they were free.  With a 5/16 hose barb, I connected the coolant lines together and clamped them down so the engine could still be run.

Once the unit was fully disconnected, I rotated the front to starboard and rocked it out.  Note that it is tight, and I had to cut the locker cover lip in about 1/4" in for about a 1" section to get the last little bit of needed space.  I did force it a little too, but as long as it was just the housing and not the water/coolant connections I figured I was OK.  My helper suggested bending the mounting tabs to get more clearance, but they looked pretty sturdy and we left them alone.  That was a good call since we found the mounting tabs are actually welded to the tank itself and not the housing.

After disassembling the housing, I can easily see where water would drip from a fitting inside the housing and leak out the bottom but the tank itself is still good.  It's worth a look berfore buying a new one.  I'm also considering modifying the housing slightly to ease re-installation by knocking an inch off the upper corners and maybe split the 1 piece cover into two.  

Good luck.  I'm still looking for good pressure testing methods too.

[Stu Jackson]

Brian

Don't use city water pressure.  It's usually about 70 psi, way more than the output of the pump on board.  If you need to use city water, go buy a pressure reducing valve at West Marine, just like they use for boat plugged into city water at marinas.

Why not call Seaward and talk to them.  I recommended this to Gary at CO.com and he called them and ten minutes later had his answer.

The fact that so many of the products on our boats, as well as the boats themselves, are still being manufactured, we should all keep in front of our minds that a phone call is a very simple way to start to get answers (including here, of course).

Stu

[reedbr]

I took Stu's advice and called Seaward.  Lonnie there was very helpful.  He said testing with city water was fine since the tank itself was tested up to 300psi.  He also said to block off the hot-out opening with a 1/2" mail NPT plug, and get an adapter for the cold-in to a garden hose connector (Home Depot item).  Then stand it on end with the releif valve pointing up and turn on the hose.  Crack the releif valve until water comes out and the tank is full.  Close it and lay it back down to look for leaks.

One other interesting point, he recommends opening that relief valve once a year as maintenance to make sure it doesn't get caked with crud.  That way it can work as designed if it ever needs to.

Off the Home Depot....

[Jim Rose]

Brian,

Thanks for your steps in removing the heater.  Did you loose much engine coolant when you disconnected thoes lines?  Hate to get an air pocket.  Maybe by removing the two 4D's would give the extra wiggle room needed.  Glad to know there is another fitting under the housing.  Will check that before buying another heater.  You're right about catching a couple of knuckles, looks like that kind of a task.
Thanks for the help Brian.

[Ken Juul]

Brian,

When mine started leaking it was from the case where the engine coolant lines come in and out. The tank was 12 years old so I chose to just replace it than try to figure how to get it welded.  Hopefully yours is just a fitting.

A word of caution, if the pressure relief ever pops from over pressure it should be replaced.  I agree that opening to  clean yearly is a good idea, I do it when I drain to winterize, so the crud doesn't get hard over the winter.

PS.  We moved Luna Loca to Deltaville couple of weeks ago.  Will miss Solomon's, but not the 3 hour drive.

[reedbr]

Well, I ran the test last night.  It looks like I really need to crank down on my cold water fitting, but other than that she holds water under pressure.  Looks like I might have saved my $300 for a new one.  I took some pictures just in case anybody wanted to see what the inside of that water heater box looks like.

Ken-  That explains why I didn't see Luna Loca on the hard or in the slip a couple weekends ago.  I can't argue with making a shorter boat-commute though.  Have fun in Deltaville.  A great jumping off place for the ICW.

[Jim Rose]

Brian,

I would like to see the pictures you took inside the water jacket.

Thanks Brian

[reedbr]

Pics as requested from disassembly and pressure testing with a city water system.

http://users.erols.com/reedbr/c34/

[Jim Rose]

Brian,

Thank you for the very detailed pictures and steps you took to trouble shoot your leak.  My friend and I both own 34MKII's that have similar leaks.  No leaks coming from the fittings.  I was leaving my pressure off when not in use.  Would like to fix the problem.  All  the other little bugs have been corrected in the last three years.

Thanks again.

[reedbr]

I'm just doing a final follow-up.  I cleaned, painted, and reassembled my hot water heater last week and installed it this weekend.  The problems seems to be solved by replacing the fittings.  By the way, I ground down the mounting tabs a little to ease reinstallation.  It went pretty smooth, less than a minute of cussing.  This was tight beacuse I was lazy and didn't remove my 4D batteries before removal and reinstallation of the water heater.

I ran the engine too and I'm not sure if my boat needs the system burped as other have noted.  I didn't do anything special and the engine heated normally after half an hour at idle.  

Jim- You noted that your fittings weren't leaking.  I couldn't tell if mine were either since it leaked down at the fitting threads and was wicked away by the insulation where it later collected at the bottom of the tank housing.  It's worth a look to remove it and test.