Water heater to engine hose sizes

[britinusa]

We decided that with all the other work in progress on the Engine (Hump Hose, Riser, New Mounts, Total new Engine Harness) we would add the re-attachment of the water heater to the engine.

The old hoses are totally suspect, not even sure that they are correct type or size.

My understanding is that the hose from the heater should be 5/8" nylon reinforced to a reducer then 3/8" from the reducer to the Engine thermostat.

Any recommendations on brand/supplier/correct size/type ???

Paul

[KWKloeber]

Paul,

Yes 5/8, to 5/8 x 3/8 nylon reducer, 3/8 to the two thermostat bypass hose nipples.  I always recommend wire-reinforced, series 250 hose (e.g., Shieldflex II) for engine hoses, unless there's a reason not to (e.g., flexibility, bend radius, etc.)  The problem is, I can no longer get shields hose in 3/8 size.  A good-quality auto heater hose can be substituted (usually a well-stocked NAPA will have 3/8 hose on a bulk reel.)  You can also use Shields series 160 hose, but I wouldn't go as "low" as series 135 or 130 heater hose.

-kk

[lazybone]

If you haven't already, change all your fuel hoses.  I had a small split develops at a bend and you can't imagine the stench and the mess diesel makes.  The clean up is a nightmare.

[britinusa]

Thanks Ken.
Found the hose at our local Napa 

Paul

ps. I was so tempted to ask if they had and P's and when they responded 'No' then ask if they have any O's!

[Ron Hill]

Paul : Get "Gates" brand hoses - made in USA.  Water and Fuel and the drive belt!!

A thought

[britinusa]

Thanks Ron, the hoses are Gates :)

Replacing the old, detached, heater to engine hoses was a breeze. I cut them both just below the 5/8" to 3/8" reducers and then joined the old hose to the new by inserting a piece of the old 3/8" hose inside, eg in place of the reducers.
Then I was able to push the old hose from the engine end and gently tug on the heater end to steer the hoses down and forwards. Easy!

Noting the the hoses were not attached since before we purchased the boat 16 months ago

I found that the hoses would be kinked if I attached them directly to the water heater nipples on the back (stbd) side of the heater.  So I would like to put in an elbow close to the tank.

Which is the better choice of elbow? Metal (Brass/Copper/Bronze) or Nylon ??

Thanks.

Paul

[KWKloeber]

Paul,

When I replaced my WH I also needed to turn the corner --- I cut off the "bulb" on the WH hose nipples and slid on Sharkbite elbows from Home Depot. 

I also elbowed the potable water connections.  I made up elbows by soldering up a copper male adapter, street elbow, and terminated it in a male (and female) garden hose thread.  I have matching male and female GH fittings on the water lines.  If I want to pump pink stuff, I just disconnect the lines from the WH and screw my two hoses together.  So, I don't need an expensive fancy pants manifold or 3-4 valves and tees to bypass the WH from receiving antifreeze.

k

[Ron Hill]

Paul : What you might want to do is what I did to protect the heater hoses from rubbing on any chard that may be on the inside of the hull.

I took some 3/4" home pipe insulation and slid it onto the hoses from the galley side.  The insulation will keep the hoses off the hull - so they cannot rub!!

A thought

[britinusa]

Great idea Ron.

[Stu Jackson]

Paul, in my Tech Notes about water heater replacement that I did in September of 2013, I suggested that one add extensions at the fittings at the back, and then connect the heater hoses from the engine.  No elbow required.  That tech note was probably sometime in 2014.