water heater woes

[mdidomenico]

I purchased my '89 C34 knowing full on that I'd have to replace the water heater, as it was rusted and icky...  but little did i know how bad it was...  oh and the big hole is NOT part of my deconstruction of the outer shell.  that's how i found it once i took the insulation off...

[Noah]

Hmmm? Somebody please correct me if I am wrong, but that doesn't look like the original  '89 OEM water heater?

[Ron Hill]

Guys : That's what the inside of the "square" water heater looks like. 
I suspect that at some time there was a freeze that did in that water heater!! 

A thought

[KWKloeber]

Hmmm? Somebody please correct me if I am wrong, but that doesn't look like the original  '89 OEM water heater?

Yep, a Seaward 5 gal.

MD, the case wasn't around it, or did you scrap that pulling it out of the cabinet?

-k

[mdidomenico]

MD, the case wasn't around it, or did you scrap that pulling it out of the cabinet?

yes, it was an old seaward unit, with insulation and a squared off housing around it.  here pics of the unit back from the survey

[Noah]

Ah ha! Now I get it! It was the round peg in square hole that threw me!

[Craig Illman]

It looks pretty dangerous indeed! 

[Stu Jackson]

mdid,

Thanks for that fine photographic presentation.

A question:  Before you removed it, did you still have the heating loop from the engine functional?

A friend is experiencing no hw when he runs his engine, a new-to-him issue.  I just learned about it tonight, so we haven't had any time to actually troubleshoot.  But he has no water in his bilge and his engine doesn't overheat, so that coolant part of his circuit seems to be intact.  Just wondering what your experience was.

Thanks.

[KWKloeber]

Stu

The problem is on an M-25//xp with the same WH hose setup?

The WH loop could have a blockage (or air lock) and the engine wouldn't necessarily overheat. Hot coolant just wouldn't get to the WH. What could occur, though, is the block could be damaged if it develops a hot spot(s) because the coolant isn't flowing before the Tstat opens. 

http://c34.org/bbs/index.php/topic,9868.msg75253.html#msg75253

Verify that there's coolant flow in the return hose back to the coolant pump (most think the coolant pump "pumps" to the Hx, but it actually "sucks" from the Hx and pushes coolant back thru the engine block.)

[mainesail]

This is why you drain then bypass a water heater and don't try to winterize it with propylene glycol.... That one looks like it froze, I see this with some regularity up here in the Great white North... That said I would urge anyone to consider something better in quality, such as an IsoTemp, rather than these beer can water heaters, when it will fit..

[scgunner]

    mdid,

        That's what mine looked like(2nd set of pics)before I junked it. Do yourself a favor go tankless, you'll never be sorry. You'll have as much hot water(not warm)as you can use and you won't have to run the motor to get it.

[Stu Jackson]

Stu

The problem is on an M-25//xp with the same WH hose setup?

The WH loop could have a blockage (or air lock) and the engine wouldn't necessarily overheat. Hot coolant just wouldn't get to the WH. What could occur, though, is the block could be damaged if it develops a hot spot(s) because the coolant isn't flowing before the Tstat opens. 

http://c34.org/bbs/index.php/topic,9868.msg75253.html#msg75253

Verify that there's coolant flow in the return hose back to the coolant pump (most think the coolant pump "pumps" to the Hx, but it actually "sucks" from the Hx and pushes coolant back thru the engine block.)

Ken,

I started that link.  Perhaps I misunderstand your point.  My friend had run his M25 engine all day.  No overheating.

Page 33, Figure 13 in the M25 manual shows that the water heater would be in SERIES with the coolant circuit.  If so, would not a blockage in that "leg" of the circuit cause engine overheating if was blocked with thermostat open?  Are you indirectly saying the thermostat may not be opening?

[KWKloeber]

Stu

The link was direct to MY post, explaining to Noah what that hose is, and how the WH loop works. Take a read thru it.

On all y'alls boats the bypass hose was removed from the OEM M-25//xp engines and the WH put into a parallel loop, BASICALLY replacing the OEM KB loop created by the short bypass hose.  It's just a MUCH LONGER loop and has a WH coil in the middle of the loop. See my pics showing the hose that your WH loop replaces.

Even on the early C30 M-25s, the Hx was never in series with that bypass hose. The short hose existed OEM Kubota on the early engines  and at some year? CTY changed to the setup the MkII C30 and your boats have. (I made that mod  to my Mk-I /  M-25).

I'm not sure which manual you're referring to?  Parts? Owner/Ops? Service?
The pic I pasted (parts manual) in my post shows no Hx in series. The pic SHOWS the bypass hose which is CORRECT.  That's OEM Univeral and Wb.
CTY is the one who scraps the bypass hose when they plumb  to the WH.

That WH loop replacing the bypass hose is WHY we get H W so quickly. Circulating coolant is heating the water because it's NOT in series w/ the Hx, and H W doesn't depend on the thermostat opening.

In effect one can disconnect the WH and plug both hoses (not have to connect them together) and won't overheat. BUT it's dangerous because of the "hot spots" I explain in my other post.

Make sense or did I muck it up further?


-K

[KWKloeber]

Stu

Ok I see —. In the OPS manual.

The FIG 13  is wrong, it has a couple flaws in it. 
When I get time I will 'adjust' it and post the correct flow pattern.

It doesn't show a WH so one can't infer anything about the loop from that fig.

K

[mdidomenico]

A question:  Before you removed it, did you still have the heating loop from the engine functional?

presumably the loop itself was still intact.  i was able to run the engine during survey and winterization without a loss of coolant or anything.

i did pull the hoses between the water heater and the engine.  they were in really rough shape, but still "intact" enough

i never did fill the fresh water side of the plumbing stuff, figured there wasn't any point since all the hoses and tanks needed to be replaced or cleaned