hoses from engine to water heater

[Jeff Kaplan]

on my m25 engine, i am toying with changing the 2 - 5/8" hoses from the engine to the water heater or at least getting a 6' section cut to keep on the boat, just in case. after removing one of the hoses, i noticed the were "shields" wire inserted water hose. i was wondering if regular heater hose could be used. is there pressure that could collapse the hose, which is why wire is inserted, or does this function like an auto or truck where antifreeze goes thru the heater hoses, into and out of the heater core? if there is no high pressure or  suction, a high quality silicone impregnated heater hose could be used, which of course, is much less money and far more flexable. the hoses may have been changed in the past, i don't know. any info on this would be appreciated thanks...jeff

[Stu Jackson]

Jeff,

What's the question?  Saving some $$ on the hose?  If that's th case, I would submit that the greatest danger to the hose is from the outside of the hose underneath the galley sole.  There's just no way to make sure it is secure and won't chafe, so the best, ribbed hose you can get would be my recommendation.  If you use less expensive hose, then it's gonna to be something you'd have to do, yet again, sooner, rather than later.  Figure what your [sailing] time is worth and compare it to the $ difference between hoses.

As I noted in that thread: "Since this hose carries your fresh water coolant, if you have ANY QUESTION about its integrity, change it out NOW.  It's not worth waiting for a blown engine."

Here's what we did:  http://c34.org/bbs/index.php/topic,3769.0.html

[Craig Illman]

Jeff - Along with Stu's observations, I think it needs to be wire reinforced for the sharp bend as it passes through the sole, then forward to the heater.

Craig

[Jeff Kaplan]

stu, i'm all for saving a buck, but i don't sacrifice quality. gates green stripe silicone impregnated heater hose is of very high quality and is used throughout the trucking indudustry, and i have access to it.  my question really is whether the system is under suction, which would collapse any  hose other than wire inserted. as far as chafing under the sole, wire does nothing. its the outer casing that counts. if wire inserted hose is the correct one to use, that's what i'm asking ...jeff

[Stu Jackson]

Jeff, it's part of the freshwater cooling system.  I have wire reinforced hoses from the manifold to the HX and to and from the freshwater pump.  It's simply a branch of the same system off the thermostat.  Given the fact that it's pumped, there is some pressure, which I would see as the same as the filler cap at the manifold, which I remember as 13 psi.

[canuck]

I just replaced the 11" hose from the exhaust manifold to the H/X on my M35B. The original hose had a wire insert. I was advised by Gallery Marine (Universal dealer) that if the hose was to have any suction issues, bends or subject to chafing then go with a wire insert. In my case it did not and hence the "softer" hose would be acceptable. It was also very much easier to install!
Since you have a longer run and possible chafing and the hose disappears from view, (out of sight, out of mind), go with the wire insert. In my case the price difference was negligble. If it's a bit more, so what, the piece of mind would be worth it!

[Jeff Kaplan]

canuk, i also have wire inserted inserted 7/8" from tank to hx, but the 1/2" hose from the hx to the water pump is just 200 psi rubber hose and the 2  3/8" hoses leading to the wire inserted hoses are just rubber also. that is why i started this post. money matters, but as i stated above, i don't sacrifice quality...jeff

[Ron Hill]

Can : There is no acute turn or "suction" that dictates a wire reinforced hose. 
As far as Stu's concern about chafing on the inside (unseen) possible hull chard's, here's what I did many years ago.  I took the 3/4" foam insulated split tubing and slid a 3/4 ft sleeve over both of the water hoses to protect them. 
When I need to replace mine I'll use regular nylon reinforced heater hose that you can get at any automotive parts store!!   

[Jeff Kaplan]

thanks ron, thats the info i was looking for, whether this was a suction or pressure system that requires wire inserted hose.  i was figuring on putting chafe guards on the hoses if i went with gs heater hose, be it foam or what they use on trucks...jeff

[Steve McGill]

I installed a new water heater on Saturday. After looking at the write-up from Stu and the state of his hoses I decided to go with wire re-enforced as he did. I was not sure of the condition of mine or whether they were original. I tied the new to the old and did the push- pull. Having arms with a 37" sleeve made this an easy task.

My hoses were in much better shape then Stu's, but still worth the change out since these are never visible.

On a side note, with the water heater out this was a great time to try and make my fresh water galley pump less loud when running. Even with the rubber bushings / feet I thought there was too much vibration. I unscrewed the pump and screwed down a piece of water pipe on each side to the wooded base. I then screwed down the water pump on top of these pieces of pipe.

The sound level has been reduced by half, but still enough noise to alert use if there is a problem.

Steve

[Jeff Kaplan]

steve, for what its worth, i ended up using wire inserted hose also. i bought 12' and cut in half. we tied the old to new and a friend pushed while i pulled, no problem. also tooks ron's advice and prefilled the hoses with antifreeze. much easier job than i expected...jeff

[David Sanner]

While I wouldn't think there would be any suction on the
hoses there is pressure... the PSI being set by radiator cap.
I forget what the stock cap is but 15psi is typical?  Perhaps a
pound or two of suction as the coolant is drawn back from the
reservoir. (but since those hoses are low in the system probably
there would be no appreciable suction)

However I think I would go with the same quality hose that
runs around the engine because it's running the same
160-180+ degree water through it.

I checked WM and it looks like their clear reinforced
water hose is only recommended to 150 degrees.
Perhaps they sell a similar one that would be rated
for typical operating temps.

Even if it was good to 200 or so I think I'd still want
the same type of hose that's on the engine to make
sure it would hold up in case of the engine water
overheating...   a 50/50 mix under 15psi can get
quite a bit above 212 before it starts to boil.

Wrapping the hoses in foam insulation sounds like
great idea... keeps your cabin sole cool as well.

[Ron Hill]

David : On replacement hoses that are not wire reinforced, I use auto heater/radiator nylon reinforced hoses. 
I've even done that for the hoses leading to the head sink - they eliminate the stinky water that forms in the reinforced polyester clear hoses.  I always look for the Gates or Goodyear brands - both are good companies that I trust.   
A thought.   

[Jeff Kaplan]

david, i'm with ron in that if you don't use wire inserted hose, definately use a good grade of automotive radiator/heater hose as suggested. gates greenstripe is excellent, silicone impregnated...jeff

[David Sanner]

I'm with Ron too... I thought he was talking about the clear reinforced
tubing that is typically used for H/C fresh water.

Another thought, the wire may not be needed for vacuum in the hose
but could help to keep the hose from kinking as it runs under the
floor and makes its connections.

Sounds like decent HW hose would work if installed correctly.