Water Heater/Air Conditioning system

Sep 11, 2019
165
Hunter 386 Lake St. Clair
What's the best way to winterize our air conditioning system? Any pointers for running antifreeze through? If I put a few gallons of rv antifreeze in our fresh water tank and run all the faucets, will that be good enough? The reason I ask, see pictures. These 2 hoses run from the hot water tank to the engine. Note the cap fittings. Will my flush be good enough, or do I have to drain through these fittings? Thanks a bunch,
 

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Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Don't put AF in the water tanks. It does not flush out easily. Pump the water tanks dry. Drain the hot water tank and by pass it with a by pass kit or by connecting the inlet and outlet hoses. At some convenient place, disonnect the supply to the freshwater pump and connect a short hose to it the other end fo which is in AF. Run all the faucets, how and cold, until AF runs from all of them.

For the motor, the coolant should be antifreeze. Disconnect the seawater intake hose from the strainer or the seacock, attach a short hose leading to a bucket of AF. Run the motor until undiluted AF comes out. Put the intake hose back on.
 
May 17, 2004
5,028
Beneteau Oceanis 37 Havre de Grace
The hoses from the water heater to the engine carry engine coolant to the heater, so no need to worry about that part of the circuit - it’s already antifreeze.

To winterize the potable side of the water heater you have a couple options. One is to drain the heater completely (from a drain our outlet at the bottom of the tank). Then you can bypass the heater (they make bypass kits for this) and pump AF through the rest of the hot and cold plumbing. The other option is to drain as much as you can and pump AF through the whole plumbing circuit, hot and cold. If you don’t bypass the heater it’ll take quite a few more gallons of AF to fill the heater and to make sure you get any residual water out of it. It also makes the recommissioning process in spring a little harder when you need to purge all the AF out of the heater.

For the AC you should be able to take the raw water intake off its thruhull and put it in a bucket of AF. Run the AC until you have AF getting pumped out the outlet. AC pumps can be hard to prime, so getting it to prime from the bucket may be tricky. I’ve had to resort to a separate pump (an aquarium power head in my case) to help get the AF from the bucket into the plumbing. If you have a separate pump or circuit for the AC condensate be sure to pour some AF into its collection pan so that plumbing gets winterized too.
 
Jul 8, 2005
512
Jeanneau 389 Grosse Pointe Farms, MI
What's the best way to winterize our air conditioning system? Any pointers for running antifreeze through? If I put a few gallons of rv antifreeze in our fresh water tank and run all the faucets, will that be good enough? The reason I ask, see pictures. These 2 hoses run from the hot water tank to the engine. Note the cap fittings. Will my flush be good enough, or do I have to drain through these fittings? Thanks a bunch,
Hi Gary,
You got some good input to your questions.

FOr the hot water heater, we drain it. We then bypass buy connecting the hot and cold together.
I put a elbow on the water inlet in the fresh water tank. Put a hose on the end and ran to a gallon of pink. Made is easier to run the the fresh water system. Don't forget the cockpit shower head if you have one.

Pump out the bilge and put some pink in there too.

When done, i do blow out what is in there with a small $30 compressor.

On the AC, we shut off the water intake at the thru hull. Run pink into the system until coming out. We have a condensate pump which needs to be winterized. Last year I pulled the pump. THis year, I will put pink in the condensate drain pan.
For the engine, I close the water inlet thru hull. l pour the expensive engine anti freeze (green I think). Pour thru the engine strainer.
DOn't forget to open all thru hull valves!

Don''t forget to winterize the toilet. Not sure which one you have.

Send me a direct message if you have more questions. We are also on Lake St Clair.

Chris