Hose replacement to HW heater w/ Hose Flix

[Stu Jackson]

After the loss of our fresh water coolant, we have determined that the 5/8 inch hoses from the thermostat to the hot water heater, which run under the galley sole, need to be replaced.

I figure that replacement would work like this:  remove existing hose with a tag line connected, connect tag line to new hose by drilling a small hole at the end of the hose, pull new hose with tag line.

Because of the very small clearance between the hose and the hole(s) in the bed of the engine compartment, using a connector with hose clamps won't seem to work.

For those who have replaced those hoses, I'd appreciate any additional pointers you may be able to provide.

[Craig Illman]

Stu - Since there's a quick 90 degree turn after it passes thru the engine bed, I think someone's going to need to be pushing/feeding while someone else is at the heater end is pulling. Given that, I think you could use short barbed connectors without clamps if they fit somewhat tightly. Your tag line idea is probably just as easy. 

Another idea, run a fish tape up the existing hose from the water heater end to the engine, extend the fish tape to allow the old hose someplace to get out of the way, then feed the new hose from the engine end over the fish tape toward the heater.

Then, last resort, there's always the sawzall!

I should tackle this project sometime myself. I'm working through pro-actively replacing my engine hoses. I'd also like to add a tempering valve on the "house" side of the hot water heater. Given the age of my boat, I probably should replace the water heater while I'm at it.

Craig

[Ron Hill]

Stu : On my 1988 boat I know that those hoses are of 2 differant types: the wire reinforced from the starboard side of the engine to the water heater and then regular nylon hose from the brass connectors on the starboard side 3/4 of the way up to the thermostate.
Are they of the same size dia.? don't know! Will check tomorrow.   

[Mike and Joanne Stimmler]

Stu,
I replaced my water heater and hoses last year and had no problems at all. We simply pulled out the old hoses and pushed the new ones through the holes from the engine side and was able to reach under the floor from the water heater side to retrieve them. You may be able to reach them easier from under the sink and then you can pass them to the left to the access door.

I remember they ARE the same size hoses but there are reducers at the engine side. I had pondered whether it mattered which way the flow goes and I don't think it does.

I belive it was Ron who recommended to leave the hoses disconnected at the engine side after you connect the water heater side and use a funnel to pour your 50/50 mixture of anti-freeze into one hose until it comes out the other hose to insure that you get all the air out of the system and then connect the engine side hoses. That procedure worked GREAT!!!

I think you'll find that its easier than you expected.

Good luck and let us know how it goes,

Mike

[Ron Hill]

Stu : Plot thickens!!  I read your analysis and Mikes' reply - interesting.

My hoses are of 2 sizes!!  There is wire reinforced(wet exhaust type) 5/8" hose from the water heater to 3/4 up the starboard side of the engine.  There are brass reducers connected to that 5/8" hose and it then is 3/8" nylon hose to the outlet of the water pump and the inlet of the thermostate housing!!!
I'm going to guess that they had to change the hose sizes because the M25XP engine fittings are 3/8" and the water heater fittings are 5/8" !?! 

Hope this helps?   

I just checked another C34 1989 and it had the same setup as my 1988 (M25XP). 

[Stu Jackson]

Thanks for all your input, your assistance is much appreciated. 

The old hose was completely shot underneath the galley sole.

The 5/8 inch hoses do indeed have a reducer fitting in the engine compartment for the short run to the thermostat and freshwater pump.  The 5/8 hose is attached by hose clamps to the barb underneath and were easy to remove.  Under the galley sink the 5/8 inch hoses also either get reduced to 3/8 inch or are just connected by a barb to the same size hose for the final run to the heater.  That shorter hose at the heater end appeared to be installed by the PO when he replaced the heater just before we bought the boat.  Since there is a microwave oven directly below the galley sink, it made sense to install extension hoses when they installed the heater to avoid having to connect the main hose way at the forward end of the heater - tough place to get to.

The "TRICKS" to getting them in [working alone] were:

1.  work from the engine side TO the heater
2.  using the "tag line" concept I described in my question that started this post, instead of pulling the old hose with a tag line all the way through and then using the tag line to pull the new hose, I tied one end of the line to the other hose, using a drill to punch a hole in the hoses; the advantage of this was that it was a one step, not a two step process; the engine side ended up pushing through, rather than the pulling on the old hose
3.  start the forward end hose/hole first, by pulling / pushing that hose first, but don't push the new hose through UNTIL you get the second aft one going

I found that sitting with my back to the oven facing inboard I was able to reach to push with my left hand and pull with my right hand.  People with short arms will need help.   People with help won't need tag lines!   

[Stu Jackson]

Hoses tied together after being pulled/pushed most of the way through, new coming out of the hole, old on the sole

[Stu Jackson]

Condition of old hose - age plus rubbing on the hull underneath the galley sole

The old hose was completely shot, and soft all over.

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.

It MAY look good where you can see it, but the AGE is the best way to know when to replace it.

Those of you with the "original" Mark IIs, your time has now come to join us "Good Old Boaters."

I still have to replace the 3/8 inch hose connections from the new hose to the heater and the thermostat/pump at the engine end.

[Stu Jackson]

Length?  I used two seven foot pieces.  Here's all that is left.  I suggest you use at LEAST seven foot lengths, since your connections at either end may be in different spots than ours were located.

Mike and Ron were right about filling up the hoses to avoid having to burp the air out of this loop.  I used the funnel method, worked great.

Just for grins & giggles, when I was finished with this, the raw water side had no flow!!!

I traced it down to a worn Oberdorfer pump faceplate, replaced and now all is fine.

[Ted Pounds]

Yech!  That looks like something out of "Alien".

[Mike and Joanne Stimmler]

Stu,
When I replaced my water heater (attwod I think)the new one had all the connections on the port side and I was initially concerned because the old one had the 5/8 hoses fron the engine connected on the stbd side but it worked out better anyway because it was easy to get the hoses to the access door and everything was in one place. Did you use wire re-inforced hose? I just used standard automotive 5/8 hoses because I didn't see a need for the re-inforced ones, but then maybe I did it wrong. The hose connections at the heater are 5/8 and they are one piece to the 3/8 reducers at the engine.

Do you think you could have done it without the tag line? It somehow worked for me, but then I don't have the microwave there and my connections were on the port side.

Glad it worked out for you.

Mike

[Stu Jackson]

Mike, here's a picture of the hose I used, was wire reinforced, perhaps could have done with regular, but what the heck, it's a boat!  The hose, all 14 feet of it, cost $46.20 plus tax.  I'd recommend wire reinforced anyway, since the damage to the old hose is plain to see, so regular hose would "die" more quickly, out of sight, out of mind.

I need to check again on the connection sizes at the heater because the 5/8 size could very well go all the way to the heater, and the barbs and extensions there seemed only to be for ease of connection of the then-new heater by the PO.  In reviewing my pictures, it appears they could be the same size hose.  At least those hoses, from the heater end of my new hoses to the heater, are not 20 years old, only 9 or 10.  Thanks for noting that fact.  Now I can kick myself for not going all the way!   Folks, get at least EIGHT feet of new hose.  Mike's point is well taken, the new hose length depends on where your connections on the heater are located.

Tag line:  In retrospect, I could have done it without the tag line, because as you and Craig mentioned, it is a push as well as pull effort.  But I only knew that after I got the first hose through and found that I could reach it from the door.  The tag lines helped immeasurably, though, because of that tight bend where the two hoses both go through the two holes in the engine space. There's that first little spot where one is actually on top of the other one, and then they seem to slide off to be next to each other.  I pulled the first (forward) hose through only to the tag line, then started pushing the aft hose through the hole and needed to use an angled screwdriver to get the second hose to "bend" enough to turn 90 degrees.  It would be doable without the tag lines, but I'm glad that I used the lines.  Part of that approach came from running new wiring to our new alternator last year, so I got into the "tag line mode."  Since I had to trim the heater ends of the hoses, the holes I put into the hoses got cut off anyway.

Thanks again for your help.

[Mike and Joanne Stimmler]

Stu, my heater didn't specify a "in" or a "out" for the engine coolent lines and I can't see that it would make a difference. What do you think? It seems to be working just fine. Did I just get lucky?

Mike

[Stu Jackson]

Mike, I thought about that too, based on your earlier post.  So, I put the hoses back where they were originally, keeping track of each one.  On the picture of the new hoses exiting the "hole" one of the tag lines is identified with black marking with a marking pen (I know, everything looks black from being pulled under the sole).

I was looking at the Universal manuals for another reason and noted that the manuals show in and out directions of flow from the thermostat/pump/engine side, but I agree that no mention is made at the heater end, since the engine manufacturer isn't "responsible" for that end.  I also looked at my heater instruction/installation manual and found no in or out, just "connect here" -- and with 5/8 inch hose, so I guess you're right, the 5/8 inch hoses go all the way to the heater.

Based on the way the heaters are built, I don't think it makes a difference.

Oh, I just noticed this, under Maintenance, Item 1: "Check heat exchanger lines for leaks at regular intervals.  A leak in the system will cause coolant loss and may damage engine."  No kiddin'!

Maybe NOW I can finally get a dry bilge...

[Craig Illman]

I replaced my hoses yesterday. Stu's picture was way too scary for me! I think my biggest challenge was getting the old wire reinforced hose off the hot water tank barbs. I pulled the drawer unit out to get more working space and even moved the fresh water pump. I remembered Stu's procedure and used some seizing wire to connect the hoses end to end. It must be a pretty tight curve under the pan, because the aft hose pushed in pretty hard. I think for that radius, wire reinforced would be required for reasonable flow. On the plus side, I found no evidence of chafe like is Stu's picture. Given that I can't pull over to the shoulder and call AAA when the boat stops, I feel very justified proactively replacing all the engine hoses.

Craig