Relocating Water Heater

[JiffyLube]

I'm thinking of relocating our water heater that runs on 120v and engine heat exchanger, to another location farther from the engine than it is now. Now it's located slightly higher and behind the engine about 3 1/2 feet, and I'm thinking I'd like to locate it in another location about 1 foot above the engine and 6 or 7 feet away. The most I can get from marine water heater manuals is to locate the heater as close to the engine as possible, but I'm wondering if anyone else has relocated their water heater farther away with good results.

[olson34]

I changed my water heater location and thereby added about 12' total hose to the run, both ways.
No problems for almost a decade, but for all I know I might be right at the limit of what the iron-vane closed-cooling pump is rated for...

To add more distance yet to the hose run, in series with that coolant circuit is a Heatercraft cabin heater that adds about another 8 feet total to that circuit also.

This is on a Universal M25XP.

L

[Faster]

On a previous boat with the heating coil above the engine we added a forced circulation pump to the loop because it was hit-and-miss whether we got enough flow naturally to heat the water.

We later changed the tank to a lower profile model (lower than the engine) and didn't need/use that pump anymore. We also had a 'bus heater' (similar to what Olson describes above) in a parallel cct, that may have been part of the problem with the waterheater circuit....

On the current boat the water heater is about 6 feet from the engine with the coil hoses below the height of the coolant resevoir. It works fine (no additional space heater in the circuit).

[JiffyLube]

Obviously your "forced circulation pump" was designed to move coolant, and I've thought about the idea of an assist pump myself just in case. Was this a 12v pump?

[Omatako]

I'm actually about to do the same thing except I'm just going from one side of the engine to the other. In the research that I have done it seems that the only issue is the height and it is apparently wise to have the middle of the tank at the same height as the top if the engine.

As it happens that is where mine is now and it works just fine without any forced flow. I hope to be able to do the same again.

[Faster]

Originally Posted by JiffyLube

Obviously your "forced circulation pump" was designed to move coolant, and I've thought about the idea of an assist pump myself just in case. Was this a 12v pump?

Yes, a small Jabsco or Sherwood with an attached 12VDC motor. We got it cheap at a marine consignement store...