[C320-list] Hot water bypass

[Jeff Hare]

Hi Mike,

No long term effect to bypassing the HW heater really but there are two things to be aware of:

1) If you've got a leak in the HW tank from rust or corrosion of the tank, then the anti-freeze heating coil could be corroded and might fail as well before long.  This would allow your hot toxic engine antifreeze (which heats the water in the tank) to leak into the tank, and then out into the bilge as well.  This would most likely fail when you're under way, so it's best to do it while it's easy and before it fails.

2) If someone turns on the HW heater shore power breaker, then this could be dangerous to have the heater element running without water in the tank.  Most likely, it'll just burn out the element in short order, but it's not meant to be powered when the tank is dry.

So, if I were going to bypass the hot water tank for more than winterization, I'd pull the feed/return heater hoses at the engine block and do a short loopback between the two fittings there as well.  I'd just leave the heater hoses routed over to the HW heater so that when you're ready to replace the tank, they can be detached from the old tank, re-attached to the new tank and then re-attached to the engine.  And I'd also consider properly disconnecting the AC Breaker power to the HW Heater or Heater Element.  You could tape over the breaker switch but that'll likely make a mess of the panel that you might regret later.  BE SURE TO disconnect the Shore Power cord and shut off any inverter you might have before you mess with the AC Electrical...

Just my $0.02

-Jeff Hare
#809

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Michael Kowitt
Sent: Tuesday, May 26, 2015 6:43 AM
To: C320-List at Catalina320.com
Subject: [C320-list] Hot water bypass

Hi all,
This list has been so incredibly helpful.  I'm coming back to it once again.
Just discovered a pretty serious leak coming from the bottom of my hot water heater (checked all of the usual other fittings for leaks, and nothing).  For me, anyway, this will be a pretty big job to replace the HWH.  I'd like to just bypass it for the moment and get along with cold water only.  Right now, I can't use anything since starting the water pressure fills the tank and then causes it to leak right into bilge.
Anyway, in the past, there was a long discussion of bypassing the HWH for the purpose of winterization.  Bill Lowe offered some pictures where he connected the cold water input to the hot water output of the heater.

  before the bypass:
http://www.catalina320.com/mediagallery/media.php?f=0&sort=0&s=20091018100451183

After the bypass:
http://www.catalina320.com/mediagallery/media.php?f=0&sort=0&s=20091018100728844


Here's my question:  Can this arrangement also be used, not just for winterization, but in an ongoing way.  Is there any other risk to the system, the heat exchanger, etc. by operating under this bypass?

Many thanks to all,
Mike Kowitt
Elusive
#903