We have a 2 story building with multiple suites and some of the suites have water heaters. We need to shut the water down and drain the system to replace a backflow. Can this cause the water heaters to drain??
The shut off between the backflow and the building is old and we are afraid it may break if we try to shut it off.

The heaters will not drain just because you closed the supply line and drained the rest of the system. However, you should shut off the heaters fuel while doing this work, just to be cautious

The heaters will not drain just because you closed the supply line and drained the rest of the system. However, you should shut off the heaters fuel while doing this work, just to be cautious

Thank you
The water heaters are electric and I am afraid if they drain they will burn out the elements.
This is scheduled weekend work and at the last minute the backflow guy springs this on me.

Shut off the breaker that powers the heater, just to be safe.

The water heaters can be siphoned off if you don't close the cold water shutoff going into the heaters so I recommend shutting the cold water shutoff as well as shutting offf the breakers as Ballengerb1 mentioned.

Good luck!

Mark