For winterizing your fresh water system you will need a few items.
The number one item to have is RV type antifreeze that is safe for domestic plumbing systems. Unfortunately I see this type of product all too often.
The pictured bottle is NOT a propylene glycol product it is alcohol based antifreeze. Alcohol based products can damage certain plastics and seals. While it is cheap please don't be tempted by price and DO read the labels.
NEVER use ethylene glycol that is designed for use in automotive engines. It is poisonous! Propylene glycol usually comes in windshield washer bottles and ethylene glycol generally comes in Prestone or Peak type bottles.
Using the method outlined below the RV type antifreeze is sucked through the system pipes only, and the tanks are left dry and drained with no antifreeze to purge in the spring.
You will also want a section of hose and the associated fittings to bypass your hot water heater so it too has no antifreeze in it for spring purging.
Some other items to consider would be a five gallon bucket, turkey baster, screw driver and some spare hose of the same diameter as your plumbing system.
Why don't I just blow the lines out with air? While this technique may work on some boats it does not successfully work on all boats. Also most boat owners generally don't have large enough portable compressors to facilitate doing so. The Maine based boat yard we use for storage winterizes over 200 boats and they blow out none of them. Every boat has antifreeze sucked through the pipes because it is far more reliable.
10-NOV-2012
COMBUSTIBLE...???
Here's a simple tip. If the RV antifreeze says "WARNING:COMBUSTIBLE" walk away. A propylene glycol product is not flammable but one made with ethyl alcohol is. This cheap product is a blend of ethyl alcohol and PG. Choose a product that does not contain alcohol.
When in doubt always read the labels. Do not be tempted by price. Ethyl alcohol blends can be had for as little as $1.99 to $2.99 per gallons while a typical price on a propylene glycol -50F rated product is about $4.50 - $5.50 per gallon..
31-OCT-2013
A Better Product
Here is a shot of a better true propylene glycol antifreeze product safe for most plumbing parts. It also has a decent corrosion inhibitor. It is safe for engines and domestic plumbing systems. It has no alcohol in it.
The item in front is a sight refractometer. This is a tool I use to test the concentration of teh AF in the system to determine when I have pumped enough through the system. Samples are taken at each faucet, shower head and wash-down spigot etc...
Star Brite Aintigel -50 is also an excellent -50F product. If you are in an area that gets really cold, less than -25F then you may want to consider a -100F rated product.
08-OCT-2008
The Water System Manifold
Step 1 - Drain Tanks:
In this photo I have drained the port and starboard water tanks with the fresh water pump & then disconnected them from the manifold, via the "Shark Bite" PEX tube fittings, so they can drain into the bilge compartment, naturally & through gravity, with the rocking motion of the boat.
This photo was taken after only a few hours and it was almost totally drip free and dry at this point. This means both tanks have virtually zero water in them and will get NO antifreeze.. I prefer not to put any antifreeze into my tanks because it is a bear to get out through the process of dilution in the spring.
I'm rather uptight about keeping a dry bilge, mold allergies, that's why you'll notice a rubber stopper in the limber hole to keep the water contained in that compartment.
11-OCT-2010
Drill Pump To Drain Water Heater
Step 2 - Drain Water Heater:
I use this drill mounted pump to keep my bilge dry and to avoid draining the entire contents of my water heater into my bilge. I simply connect it to the drain of the water heater and then suck the water out and into a bucket in the cockpit. I'm allergic to mold and as such try very, very hard to keep a dusty dry bilge. As of now I am winning the battle and have zero leaks and a very arid bilge. This drill pump helps keep it that way.
08-OCT-2008
The Water Heater Drain Bucket
For illustrative purposes I used a bucket to catch the contents of my water heater after pumping it dry. You can also just drain it onto the floor of the cockpit or stick the hose directly into a scupper. Heck if you don't mind water in your bilge just drain the water heater into your boat..
08-OCT-2008
The Drill Pump
This is the drill pump I use to drain the water heater. I think it cost me about $7.00, at Wal*Mart, and has been used to winterize for over ten years now.
08-OCT-2008
Water Heater Bypass Hose
Step 3 - Install Water Heater Bypass Hose:
This is the water heater bypass hose in use. It's installed so I don't have to fill my water heater with antifreeze. I sucked all the water out first with a drill mounted pump then placed an Absorber (brand name) synthetic chamois under the drain. After a few hours of rocking at the dock no more water came out.
To install this hose simply disconnect the cold supply and hot return line for the domestic water side of the tank and connect them with the bypass hose.
Do not try to bypass the engine supply & return lines for the water heaters internal coil. these lines will usually be black, like a radiator type hose, and will not generally be the same color as the domestic water side. When in doubt follow the lines. If they lead directly to the engine they are the wrong hoses..
11-OCT-2010
Water Heater Bypass Nipple
The brass nipple between the stainless hoses is the bypass for this IsoTemp water heater.
08-OCT-2008
Remove Any Water Filters
Step 4 - Remove Water Filter Cartridge:
If your boat has any on board water filters now is the time to remove them. Simply pull the cartridge out and spin the filter back together without one.
08-OCT-2008
Add A Lenght Of Hose To Your Water Pump Supply
Step 5 - Adding Sucking Hose:
As you can see I've pulled the supply hose for the water pump off the manifold. I then use a hose barb and a spare length of hose to make an extension that could reach the antifreeze bucket.
08-OCT-2008
Using Turkey Baster To Prime The Pump
Step 6 - Priming The Water Pump:
Sometimes when you run a water pump dry, from draining the water tanks, it can become hard for the pump to create a new prime and begin sucking fluids again.
An easy way to avoid this problem is to pre-prime the water pump using a turkey baster. Not all pumps will require this trick and if yours won't prime this will do the trick.
08-OCT-2008
Filling The "Sucking" Hose
As you can see I've sucked the turkey baster full of antifreeze and am now pre-filling the hose to the water pump.
13-NOV-2012
Bucket Tip
The 5 gallon bucket I use for PG antifreeze has been graduated with a Sharpie marker at each gallon. This makes it easy for me to stop pumping, take a concentration measurement, and then continue. In the end I know exactly how many gallons it took to get the right concentration into the system, no more, no less.. In this image the bucket has exactly 1 gallon in it...
Each of the boats I winterize has a winterizing info sheet derived from the first winterizing I conduct on the vessel. The engine & domestic water systems are tested for concentration/freeze point with a sight refractometer to determine exactly how many gallons it takes to properly protect the system and reach the undiluted point. The next year I pull the winterize sheet up on my computer or iPad and know exactly how many gallons is required for the engine and how gallons for domestic water. This step avoids guessing and waste.
Remember a refractomer is measuring the PG's "freeze point" not the burst point. Don't be alarmed if a sample straight from the bottom reads 7F - 10F. What comes out the taps or engine exhaust should ALWAYS match a sample straight from a virgin bottle of the AF you are using. In other words if your West Marine Pure Oceans -50F reads 8F then what comes out of the taps or engine should also read 8F.
08-OCT-2008
Ready To Antifreeze The Pipes
Step 7: Sucking The Antifreeze Through The Water System:
With the hose full of antifreeze and the pump primed, use a clean bucket, or the hose stuffed into a gallon of antifreeze you are now ready to flip the switch.
Turn the water pump switch on and open each tap, in rotation, until it runs a color that looks the identical color in the bottle.
Run and test each tap until the concentration of the PG matches exactly what is in the new bottle. If you don't have a refractomer samples in a clear wine class placed next to a new undiluted sample can give somewhat decent guidance. When in doubt suck in more!!
Another gallon or two will ALWAYS be less costly than a freeze up!!
08-OCT-2008
Make Sure You Get Pure Pink
After you flip on the water pump switch open each and every faucet, shower head or wash down fixture. I suggest doing them one at a time, first cold then hot at each faucet. Do this to be sure all the lines are getting pure pink the same exact color it was coming out of the bottle.
Remember this type of RV antifreeze is not intended to be diluted AT ALL. Diluted antifreeze means warmer burst & freeze points. If in doubt, you can always suck one more bottle through.
23-MAR-2014
At Two Gallons
When your sample from each tap is on the extremely diluted side the differences in color are easy to spot.. This was an approx 18F spread on the refractometer. NOT GOOD!!!
Merely seeing pink is not the proper way to winterize your system!!
23-MAR-2014
They May Look The Same
In this image we have an out of the bottle sample and a sample from the spigots. This was at 3.5 gallons sucked in to the system pipes only. The refractometer readings were still a 4 degree spread.
I am not happy until the refractometer readings match perfectly.
04-OCT-2016
"But I Saw Pink?"
I see far too many frozen, split and destroyed plumbing parts including pumps, valves, and even water heaters each and every spring. I also see frozen and split heat exchangers for engines. This stuff is ALWAYS more costly than an extra gallon or two or three of propylene glycol.
The act of merely "seeing pink" tells you little to nothing. This owner sucked 2.5 gallons into the fresh water system of a 44' vessel based on the "I saw pink" protocol... D'oh.....
Cha-ching $$$$
You ALWAYS Drain & By-Pass A Water Heater
The drain cock on this water heater is there for a reason! This owner sucked 6 gallons of -50F antifreeze into his 6 gallon water heater & system without bypassing the water heater......!
Freeze, split, cha-ching $$$$$$$$$$$$$$$$$$$ !!!
DO NOT DILUTE YOUR PROPYLENE GLYCOL!!!
It would take far more than 6 gallons of antifreeze, in a 6 gallon water heater, to get zero dilution.
If you don't know how to winterize you had better know how to write checks.... D'oh!!
Water Heater Winterize FAIL
Here is another prime example of why marine water heaters are DRAINED in the winter. This owner attempted to dilute the six gallons of water with seven gallons of antifreeze.... Seems reasonable... WRONG!
Fill a 16 oz glass with milk. Now place it under the faucet and turn the faucet on. Let me know how many GALLONS of water it takes until the water in the glass is clear....... FAIL!!!!!!
04-MAR-2012
Don't Forget The Sanitation System!
I know this article is about the fresh water system but I need to make a plug for the sanitation system.
This owner did a DIY winterizing and paid a really huge price. The price for improperly winterizing the holding tank was massively repulsive odors in the boat! Come spring when the frozen shit & urine melted the leaks began, this was only one of them. The entire boat wreaked of raw sewage! He went in late and the leak was not discovered until early June. Under the hot cover the odors had baked into everything. He had flushed one gallon of -50F PG through the head. His hoses held more than one gallon and the tank still had at least 3-4 gallons in it!
This is also another reason I do not like elcheapo PVC sanitation hose. Every leak from freezing was in the white PVC hose... Rubber based hoses may have survived this, PVC did not.
#1 Holding tanks should be COMPLETELY empty BEFORE you winterize them.
#2 Hoses from head to tank should be purged of effluent by dry pumping.
#3 Try to wash out your tank before putting the boat away. Most tanks have a clean out port, use it.
#4 Ask your pump out guy to do a flush service. Evacuate, fill with clean water, re-evacuate.
#5 You may need a manual pump to get the tank dry. Pump into a 5 gallon bucket and pour it into a land based toilet.
09-MAR-2012
As A Point Of Reference
I do not accept sanitation odors as normal on our boat, or any boat. As a point of reference this is what the inside of the holding tank looks like on our boat each fall. The photo was taken through the clean out port. This is what it looks like before she is winterized.
The tank is pumped out, back flushed, pumped out again then physically hosed out via the clean out port. I then fully bleach sanitize the tank and it is 100% drained via a dip tube and utility pump. I use 1/2" PEX as the dip tube and a small utility pump to get all the contents out.. A little extra work? You bet, but well worth it to me.. The hoses are also pre-purged/rinsed before any antifreeze goes into the system.
We have zero sanitation odors on our vessel.... (wink)
27-MAR-2014
When In Doubt...
I will leave you with this image..
I simply can not stress enough the importance of not diluting the PG mixture in your systems. When in doubt SUCK MORE PG IN or physically TEST IT..
Water heaters are always drained and by-passed you do not run pink through them! See red highlighted paragraph...
Good luck, and don't dilute!!
MAY-2006
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