The GeneralAire 800-DM Diaphragm is the correct replacement for the following humidifiers:
The GeneralAire 800-DM Humidifier Valve Diaphragm, also known as part number 8019 is the genuine replacement diaphragm for the GeneralAire 800 Humidifier. The GeneralAire Valve Diaphragm attaches to the 800-M face plate with the valve body repair kit and 800-N screen disc. The water supply to the humidifier is automatically controlled by the water pressure against the neoprene pan diaphragm. Once the water level reaches about 1 inch deep in the neoprene pan, the pressure and valve seat against the orifice shuts off the water. When water is drawn from the pan and evaporates through the humidifier evaporator plates, the pressure on the pan diaphragm is reduced. This will allow the actuator plate to pivot away from the valve and opens the water inlet orifice. The water will flow from the orifice through the valve chamber and drip tube to refill the humidifier pan.
GeneralAire Humidifier Valve Diaphragm specifications:
If the valve malfunctions, look for dirt that could accumulate in the orifice and neoprene valve seat. Turn the water supply off to the humidifier, remove the 4 screws from the valve body and pull from the neoprene valve diaphragm. Next, remove the screen disc from the orifice fitting with a wire paper clip, clean both elements, then clean all of the dirt and scale from the valve seat. Replace the valve body with the orifice fitting on top, but do not over tighten. Reconnect the 1/4" water line to the GeneralAire humidifier and adjust the valve to shut off when the water level is approximately 1/4" above the holes in the pan baffle. Adjust your screws slowly until the water stops dripping from the drip tube. After testing this settling dip water from the pan, water should start dripping from the drip tube. Now the humidifier can be properly adjusted to automatically maintain this water level in the pan.