Here's how I do it for both customers and on our own boat..
With boat still in the water
drain water tanks
and disconnect pump feed/drain hoses. Allow rocking motion of boat to empty any small bit of remaining water into bilge
over a couple of days. If on the hard
, and you forgot to drain the tanks
, and lack the rocking motion, you can blow compressed air through the tank vent to finish purging the water
out the tank feed lines. BE SURE the drain lines are OPEN or you could pop the tank.... Leave tanks empty for winter.
If you have a water filter remove it:
Drain & bypass the water heater:
And another way:
If you don't want the entire contents of the water heater in your bilge pump
it out with a $7.00 drill pump..
Install short piece of extension hose onto FW pump and stick into AF bottle and then open each tap one at a time.
Test the concentration that comes out of the taps to be sure burst point is higher than what you'll see in your area. Once the lines are full of
AF I disconnect the pump supply and inlet hoses and let the AF drain out of the pump head
and reconnect for spring.
Alternatively you can blow the system out by running compressed air through the plumbing
lines. This however is not always suitable depending upon the complexity of the system and burst fittings are still possible as you do not always get all the water out, it can condense on the pipe walls, and eventually drains back and finds a low spot. Small contractor sized compressors are usually not big enough to do the job adequately.
On our own boat blowing out does not work even though that would be my preference. I did burst a fitting, so I am back to pink stuff. On customers boats I won't risk it.
In the spring I suck fresh water through the system plumbing
hoses for a good while then shock the system with bleach, drain and purge the bleach all before reconnecting the H20 heater...
No AF taste or residue and less AF used.....
We drink out of our tanks, with filters, so not putting anything but water in them is important to us.
P.S. Some fresh water pumps don't self prime well after being run dry. A turkey
baster can easily fill the hose and aid in priming it.