Replacing coolant hoses to water heater

buddybear

buddybear

.
Apr 17, 2013
182
Catalina 310 57 Pompano Beach, FL
In the process of changing the coolant hoses from the engine to the water heater. On one of the hoses at the water heater there is a plastic inline bleed valve. I have never used this when bleeding the air from the system after changing coolant. It is in a location where it is not easily accessible. All of the bleeding I have done is in the engine compartment. Any reason why I can't just eliminate this valve and plumb the hose directly to the fitting on the water heater. It would make installation easier. as I said earlier I have never even turned this valve.

Thanks,
Mark
 
jssailem

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
24,516
CAL 35 Cruiser #21 moored EVERETT WA
No reason at all if you have not been using it.

As long as your procedure has been working, that is one less hidden failure point on the lines.
 
Stu Jackson

Stu Jackson

.
Feb 26, 2004
23,328
Catalina 34 224 Maple Bay, BC, Canada
Bleeding (or as we call it Burping) is required to get air out of the hoses between the heater and the engine because the freshwater coolant pump on the engine cannot pump air, only water; if air is in the line, the engine WILL overheat.

Bleeding can only be done at the high point of any pipe/hose loop.

In some boats the heater is above the engine, so a vent at the heater will work.

In other boats the heater is below the engine, so the vent at the heater is useless. The vent at the engine is usually on top of the thermostat; others, like me, choose to fill the hose to the heater with coolant manually to eliminate the air.

Your boat, your choice. :)
 
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buddybear

buddybear

.
Apr 17, 2013
182
Catalina 310 57 Pompano Beach, FL
Stu Jackson said:
Bleeding (or as we call it Burping) is required to get air out of the hoses between the heater and the engine because the freshwater coolant pump on the engine cannot pump air, only water; if air is in the line, the engine WILL overheat.

Bleeding can only be done at the high point of any pipe/hose loop.

In some boats the heater is above the engine, so a vent at the heater will work.

In other boats the heater is below the engine, so the vent at the heater is useless. The vent at the engine is usually on top of the thermostat; others, like me, choose to fill the hose to the heater with coolant manually to eliminate the air.

Your boat, your choice. :)
Click to expand
I fill the hose to the heater manually as you do and it has been working well.
Thanks
 
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Stu Jackson

Stu Jackson

.
Feb 26, 2004
23,328
Catalina 34 224 Maple Bay, BC, Canada
Hello Below said:
Have a read of this link. Reconnecting water heater and bleeding the system?

For the price of a pint of a craft beer at your local pub you can purchase a utility pump (Post #6). I find it a very useful tool on the boat.
Click to expand
I have one, but have never used it for this Burping process since gravity works just as well.
When I recently had my HX replaced, our mechanic Doug (you know him, too) had a really nifty tool. It connected to the exhaust manifold, replaced the "radiator cap," and he pumped away for maybe 20 seconds with the thermostat air vent opened. Once bubbles started showing he pumped a little bit more, and then was done.
Neat tool, but way pricier than a utility pump.
 
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C

Clydo

.
May 28, 2013
371
Catalina C310 SF Bay/Delta
Stu Jackson said:
I have one, but have never used it for this Burping process since gravity works just as well.
When I recently had my HX replaced, our mechanic Doug (you know him, too) had a really nifty tool. It connected to the exhaust manifold, replaced the "radiator cap," and he pumped away for maybe 20 seconds with the thermostat air vent opened. Once bubbles started showing he pumped a little bit more, and then was done.
Neat tool, but way pricier than a utility pump.
Click to expand
Stu how/where did he connect to exhaust manifold? Where can anyone get such a tool?

Thanks

Clyde Thorington
C310 # 245
I LEAN TOO
San Jose, CA
 
Stu Jackson

Stu Jackson

.
Feb 26, 2004
23,328
Catalina 34 224 Maple Bay, BC, Canada
Clydo said:
Stu how/where did he connect to exhaust manifold? Where can anyone get such a tool?
Click to expand
Clyde, did you miss this ^^^ part? Screwed into the radiator cap. I didn't want to use that phrase in a family setting.:(
 
Ralph Johnstone

Ralph Johnstone

.
Jan 4, 2006
7,626
Hunter 310 West Vancouver, B.C.
jssailem said:
No reason at all if you have not been using it.
Click to expand
It's not earning its keep, so over the side with it.



Colour me lazy but ....................................

The first time I changed the AF in the cooling system of the Yanmar 2GM20F I dutifuly drained every drop out of every hose to and from the HEX. After that little exercise of filling everything with air, I had my doubts the engine would ever run more than a few minutes again. I had a temp. gauge on the system and all it ever did was overheat while I tried to purge all of the air while idling at the dock. I also had an air vent at the highest point in the system at the engine. No luck.

1770485189878.png


Eventually, I did get all of the air out but was almost purged from the marina for language unbecoming a member. ^$%#*&%!@ :cuss:.

Figured I'd never do that again in this lifetime. So ......................... seeing as how the engine was now running smoothly again temperaturewise, I would never disturb the lines to and from the HEX again.

Renewing the AF became a breeze after that. I drained the engine capacity of 3 liters of AF and did not disturb the hoses to/from the HEX. Refilling was a breeze and I purged what little air there was in the block through the air vent at the top of the engine. After that, any bubbles remaining would be so small as to be swept away into the top of the reservoir and from there into the AF overflow.

Seeing how there was still a little stale AF in the hoses, I decided to change the AF every two years to be sure the anti-corrosive chemicals as well as the eye of newt and grasshopper tongue were up to strength. Cost was minimal and changing the AF was now a breeze.
 
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jssailem

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
24,516
CAL 35 Cruiser #21 moored EVERETT WA
When I first installed the Water Heater, I was worried that the coolant was not completely dispersed. I heard that if you rocked the boat, you could move the air bubble through the hoses. So I put my biggest crew member standing on the rail, and he grabbed the shroud and hung their butt out over the side, rocking the boat back and forth while the engine idled. It looked funny, but it worked.
 
M

max_sailing

.
Jul 28, 2024
70
Catalina 310 238 Berkeley, CA
I recently replaced the water heater and those hoses, all the way back to the thermometer housing where they connect. I removed that valve, as it seemed like it had been rusted shut for decades. I did not pre-fill the lines. I just topped off the coolant reservoir. After a few minutes idling the reservoir was nearly empty and I filled again. After the test run out of the marina, it similarly drank the reservoir and I refilled. The temperature gauge stayed normal throughout. Maybe I was naive, negligent, lucky, or some combo thereof. I’ve done a few hours of motoring since with the temps staying normal.
 
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