Engine and H20 heater question

J

JPS27

.
Sep 9, 2016
2
Ericson 27 Hampton
I have a new to me Pearson 36-2. A relatively big step up from my Ericson 27, so I'm learning systems, instruments etc. My questions are about winterizing the engine and water heater that are connected.

I live in southern Chesapeake area. With my old Ericson I would winterize the engine (2qm15) by just running anti freeze thru it. If a nice day came up in Jan or Feb I take her out and then re-winterize.

On my Pearson I winterized the water heater by draining it and bypassing the water lines to fill them with anti freeze. I have a 30YM30AE with 100 hr on it and the raw water side is also winterized.

Would I damage the water heater (or more importantly the engine) if I took the boat out for a sail while the water heater is winterized? I'm trying to understand how the engine heats the water in the water heater. And if there's no water to heat, would it create a big problem.

Thanks. Jay
 
kappykaplan

kappykaplan

.
May 1, 2011
4,247
Pearson 37 Lusby MD
JPS27 said:
Would I damage the water heater (or more importantly the engine) if I took the boat out for a sail while the water heater is winterized? I'm trying to understand how the engine heats the water in the water heater. And if there's no water to heat, would it create a big problem?
Click to expand
No and no.
 
D

dlochner

.
Jan 11, 2014
11,436
Sabre 362 113 Fair Haven, NY
If the boat is plugged in to shore power with the water heater empty and someone turns on the heating element, it will burn out. Once the water heater is empty tape the circuit breaker in the off position, so it does not get accidentally turned on.

The engine heats the WH by running a loop of coolant through a heat exchanger in the tank. Once the engine gets to operating temperature the thermostat opens and coolant flows through the heat exchanger in the tank and back to the engine before entering the engine heat exchanger.

Don't put antifreeze in the HW tank, just drain the tank. Any small amount of residual water will freeze without damaging anything.
 
jssailem

jssailem

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Oct 22, 2014
21,105
CAL 35 Cruiser #21 moored EVERETT WA
JPS27 said:
I'm trying to understand how the engine heats the water in the water heater.
Click to expand
Your engine coolant flows through the engine. A hose from the engine to the water heater (WH) moves the coolant to the WH, through it and then back to the engine Heat Exchanger (HE). At the HE cool raw water shows up. Cool water enters HE and flows over outside the tubes in the HE. The still hot coolant from the WH flows through the tubes transferring heat to the raw water. Raw water flows into the exhaust, while the coolant is retuned to the coolant reservoir to start the process again.
 
J

JPS27

.
Sep 9, 2016
2
Ericson 27 Hampton
Thank you. Got it. I appreciate the help. And I will tape over the WH switch at the panel while the WH is empty.
 
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jssailem

jssailem

.
Oct 22, 2014
21,105
CAL 35 Cruiser #21 moored EVERETT WA
Yes it could happen. But not likely when the PO is running an engine driven water heater system.

Propane explosions concern me. But even those have proven difficult to start. See this video of a test explosion by experts at Yachting Monthly
 
D

dlochner

.
Jan 11, 2014
11,436
Sabre 362 113 Fair Haven, NY
The HW tank will not explode if the electric elements are turned on while the tank is empty. The element will heat up and the hottest part will melt breaking the circuit.

The greatest danger from an engine heated HW tank is scalding because the water will be at the operating temperature of the engine, typically somewhere between 160°and 180°F. If the engine overheats and the pressure relief valve on the tank fails to open, the tank could rupture. That has the potential to damage the boat. When the overheat alarm goes off, shut the engine down.
 
Tally Ho

Tally Ho

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Jan 7, 2011
4,787
Oday 322 East Chicago, IN
If you have bypassed the water heater “coolant” lines, then all you did was make the coolant loop shorter. Should be no ill effects on the water heater or the engine.

As others have said, don’t turn on the breaker to the WH…you will surely burn out the element.

But you should be able to sail, and the run more AF through the engine to winterize the engine.

I am jealous…I stopped by my marina today to do a wellness check before I leave for Maui for 4 weeks…

The Lake Michigan was smoking! Water is ~32 F and is warm compared to the air temp.

And ice is forming in the harbor.

IMG_1936.jpeg



IMG_1935.jpeg



Damn cold…-5F currently… -30F windchill.

brrrrrr

Greg
 
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Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
6,491
Hunter 310 West Vancouver, B.C.
Tally Ho said:
Water is ~32 F and is warm compared to the air temp.
Click to expand
When the water is the warmest thing around at 32° F, it's time to look for new digs. We're in the middle of an Arctic blast and seeing 14° F and people are dying in the streets (or damn close to it). I'll be glad when we return to our norm of 45° F during the coming week. Got to get to work on my daffodils.
 
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D

dlochner

.
Jan 11, 2014
11,436
Sabre 362 113 Fair Haven, NY
Ralph Johnstone said:
When the water is the warmest thing around at 32° F, it's time to look for new digs. We're in the middle of an Arctic blast and seeing 14° F and people are dying in the streets (or damn close to it). I'll be glad when we return to our norm of 45° F during the coming week. Got to get to work on my daffodils.
Click to expand
At least the water is liquid. :biggrin: It's a balmy 15° F under sunny skies here and the wind stopped blowing.
 
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