How do I winterize a watermaker?

These instructions are intended to be generic, and specific directions for your system are provided in the Operation and Maintenance Manual. Refer to your manual for specific system instructions and chemical ratios. 

For Analog Systems:

1.  Close the thru hull.  Fresh water flush the watermaker. Turn off the feed pump. Close the grey flush valve (located on feed pump module).

2. Connect the inlet service hose to the service intake on the feed pump module, and lead it into a bucket. Connect the brine discharge service hose, and run it into a second container.

3. Turn the yellow service valve to the SERVICE position.

4. Pour 1 gallon (4L) of propylene glycol of appropriate concentration into the bucket with the intake service hose.

5. Make sure that the pressure relief valve on the Clark Pump is OPEN a 1/2 turn, OR THE MEMBRANE WILL BE DAMAGED.

6. Run the feed pump until about a gallon of water has flowed from the brine discharge service hose, or antifreeze appears. Propylene glycol will look slightly different, and feel more slippery than water. Stop the pump. Add more propylene glycol to the intake bucket if necessary.

7. Lead the brine discharge service hose into the same bucket as the intake service hose. The system will now draw propylene glycol solution from the bucket with the intake service hose and return it via the brine discharge service hose.

8. Run the feed pump to circulate the antifreeze in this manner for 10 minutes.

9. Stop the feed pump. Reconnect the brine discharge hose that leads to thru-hull. Run the feed pump until the bucket is empty.

10. Close the seawater intake. Turn the yellow service valve to OFF. Drain the seawater strainer and the hose leading to the feed pump module. Disconnect the product tubing from the membrane housing and blow the water out. Empty the charcoal filter housing and flush water lines.

Your watermaker is now protected from biological growth and freezing for one year.

For Automatic Systems with the MPC 5000:

1. Turn the yellow service valve on the feed pump module to OFF (horizontal, see photos).

2. Push Auto Store to fresh water flush the system. Repeat, to flush the system twice.

3. Connect the inlet service hose to the feed pump module and lead the hose to the bottom of a bucket. Connect the brine service hose, and run it into a second container.

4. Turn the yellow service valve on the feed pump module to the SERVICE position.

5. Pour 1 gallon (4 liters) of propylene glycol of appropriate concentration into the bucket with the intake service hose.

6. Make sure the pressure relief valve on the Clark Pump is OPEN 1/2 turn.

7. Run the feed pump using the manual switch on the MPC control box until about a gallon of water has flowed from the brine discharge service hose, or antifreeze appears. Propylene glycol will look slightly different, and feel more slippery, than water. Stop the pump. Add more propylene glycol to the intake bucket if necessary.

8. Lead the brine discharge service hose into the intake bucket of propylene glycol. The service hose will now draw propylene glycol from the bucket, and the brine discharge service hose will return it. Run the feed pump and circulate the antifreeze for 10 minutes.

9. Stop the feed pump. Close the seawater intake and turn the yellow service valve to OFF. Drain the seawater strainer and the hose leading to the feed pump module. Disconnect the product tubing from the membrane housing and blow residual water out of the tubing. Empty the charcoal filter housing and flush water lines.

Your watermaker is now protected from biological growth and freezing for one year.