Marathon Water Heater – Installation Checklist

Congratulations on the purchase of your Marathon water heater. This water heater will provide you a lifetime of energy savings if you follow just a few simple steps:

Do not apply heat to the top union nuts. Build a short assembly with male and female adapters, and solder separate from heater. After they cool, screw them onto the tee, and brass nipple.

Do not over-tighten the union nuts. There is a flat neoprene washer on the inside of these unions and “snugging” with water pump pliers is sufficient for a good seal.

Install a drain line on the temperature/pressure relief valve. Code requires the drain line to be plumbed to within 6” of the floor.

Fill the tank with water before turning on power. Vent air out of a faucet to make sure no air pockets remain before energizing. Continuous water MUST come out of hot tap before energizing

Be sure to fill out and mail the warranty registration card located in your owner’s packet.

If you have questions, please refer to the Quick Start Guide or Owner’s Use & Care Manual

Download the full checklist in PDF format for easy printing.