Reroute Water Heater Coolant Hoses

[Christian Williams]

I have the heat exchanger off for cleaning and hose replacements.

My current water heater coolant circuit is a somewhat klutzy takeoff from the heat exchanger that interferes with routine access to the zinc.

I have in mind to connect the heater from the thermostat bypass. This mod has been discussed and recommended over the years on the forum as a better setup.

Any arguments/experiences against it?

http://sankaty.homestead.com/waterheatercircuituniversal5432.html

 

[Joliba]

Hose Routing

Christian,
Although we have made some changes in the engine compartment since this photo was taken, I am attaching a photo depicting how our water heater hoses were routed when we purchased our boat in 2008. We have not changed the water heater hose routing or setup since then and have NEVER had a problem with either the engine cooling or the hot water, related to this coolant path. Our HW tank is located in the starboard cockpit lazarette. The hoses lead over the engine, as you can see. There are coolant bleed valves in one hose and at the top of the thermostat housing. When I use the bleed valve located on the water heater hose, I manually lift the hose upward so that the the valve is temporarily at the high point in the system, which is where the air bubbles will go. I have described how I bleed the coolant after refilling in a thread you began last week. I think that the modifications you are considering could work well for you.
Good Luck!
Mike Jacker

 

[Christian Williams]

Thanks for the confirmation.

I have the typical bleed valve on the thermostat, but I noticed that the hoses on top of the engine become the highest point, if only by an inch or two. A separate bleeder there seems a good idea, although others seem to do without it.

Good thing I pulled the heat exchanger, although of course now the project has grown like the usual mushroom cloud.

Ancient fossilized pencil zincs. Who knew?

 

[Dan Morehouse]

Thanks for the confirmation.

I have the typical bleed valve on the thermostat, but I noticed that the hoses on top of the engine become the highest point, if only by an inch or two. A separate bleeder there seems a good idea, although others seem to do without it.

Good thing I pulled the heat exchanger, although of course now the project has grown like the usual mushroom cloud.

Ancient fossilized pencil zincs. Who knew?

View attachment 28267Hmmm. I've never bled my coolant lines. Seems like I just open the coolant fill cap to check that the level hasn't dropped once coolant has had a chance to circulate. I also have a klutzy spaghetti bowl connecting my water heater to the coolant circuit...AND an additional circuit which runs the engine source cabin heater. But I've never had a problem with either. The pencil zincs are a pain to change, but only because when I wait too long to do it, the zinc is no longer attached to its cap. Then I have to disassemble the heat exchanger end plate to fish the fossilized zinc remnant out of the cavity.