This exhaust vent blower pressure switch (part number 9001976) is for water heaters.

Exhaust vent blower pressure switch 9001976 prevents burner operation if the exhaust vent blower does not run or if the vent pipe does not allow air to flow as required.

Disconnect electrical power and turn the gas supply off to the water heater before installing this part. Wear work gloves to protect your hands.