Water Heater Bypass

Making winterizing easier

All Flagstaff campers have a bypass line for the water heater. The bypass line circumvents the water heater to make winterizing easier.

Without the bypass line six gallons of antifreeze would be wasted to get the water out of the heater. Or, if using an air compressor, trying to blow out six gallons of water would be a much more difficult task instead of simply isolating the water heater and draining it out separately.

Flagstaff has used several types of bypass fittings in the past but they all work in a similar fashion. The idea is to run water through the bypass line and completely isolate the water heater tank.


Typically the handle on the bypass fitting indicates the direction of the flow of water.

If you only have two fittings, that's okay. The Flair-it fittings shut off the water heater line and direct water to the bypass line so only two fittings are required with that setup. One version of the black fittings used a cold-water line fitting and a bypass line fitting. It would appear that water could then back-fill into the water heater on the hot-water side. In these systems a back-flow prevention device is installed on the hot-water side of the water heater so water/air/anti-freeze can't get back into the water heater.

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