Power vent /power direct vent water heaters – To identify if you have this type of water heater look for a black motor on the top of the unit.
If your customer has a power vent or direct vent water heater and they call because the water heater is not working they will need to follow the steps below. They can even try to avoid issues by doing this today.
Note: if vents are high or on roof, they may have to wait till we warm up to do anything unless they have the ability to follow the above steps on a ladder.
If they think they have a freeze continue to leave all faucets in the house on a drip until water usage comes back to each fixture.