Water Pump: Winterizing

NOTE: When used per the manufacturer’s recommendations non-toxic antifreeze for potable water is safe for use with SHURflo pumps. Make sure all components in the system are compatible. Hot water heaters and filters must be drained and by-passed when using potable water anti-freeze. Refer to the manufacturer and other equipment manufacturers for their specific winterizing & drainage instructions.

Do not use Automotive Antifreeze to winterize potable water systems. Such solutions are highly toxic. Ingestion may cause serious injury or death. To properly drain the system, perform the following:

1. Drain the water tank. If the tank doesn’t have a drain valve, open all faucets and let the pump run until the tank is empty.

2. Open all the faucets (including the lowest valve or drain in the plumbing) and allow the pump to purge the water from the plumbing system, and then turn the pump OFF.

3. Using a pan to catch the remaining water, remove the plumbing at the pump’s inlet/outlet ports. Turn the pump ON, allowing it to operate until the water is expelled.

Turn OFF the power to the pump once the plumbing is emptied. Do not reconnect pump plumbing. It is o.k. to lightly cover plumbing ends to prevent bugs from entering the system.

Make a note at tank filler as a reminder: “Plumbing is Disconnected”.

4. All faucets should be left open to guard against any damage.

5. Potable water anti-freeze may be poured into drains to protect p-traps and waste system from freezing.

6. Fill system and sanitize before use in the spring.


Sanitizing is recommended prior to storing and before using the water system after storage.

Systems with new components, or ones subjected to contamination, should also be disinfected as follows:

NOTE: This procedure is in conformance with the approved procedures of ANSI A119.2.

1. Use one of the following methods to determine the amount of common household bleach needed to sanitize. A) 1-1/2 ounces of bleach per 10-gallon tank size. Example: 40 gallon tank = 4 x 1.5 = 6 ounces of bleach. B) Multiply “Liters of tank capacity” by 1.0; the result is the milliliters of bleach needed to sanitize the tank.

2. Mix the proper amount of bleach within a 1-gallon container of water.

3. Pour the solution (water bleach) into the tank and fill the tank with potable water. Rock vehicle back and forth to splash water on tank walls a top.

4. Open all faucets (Hot &Cold) allowing the water to run until the distinct odor of chlorine is detected.

5. The standard solution must have four (4) hours of contact time to disinfect completely.

Doubling the concentration of bleach allows for a contact time of one (1) hour. When the contact time is completed, drain the tank. Refill with potable water and purge the plumbing of all sanitizing solution.