Water Heater Wind Pressure Switch Fault Repair

Check steps:

1. Open the water inlet valve, observe whether the micro switch of the water and gas valve is closed and connected, and whether the fan is running normally.

2. If the micro switch and fan work normally, but the igniter does not ignite, short-circuit the air pressure switch. If the igniter does not ignite, it is an ignition control problem.

3. If the ignition works normally, it can be determined that the air pressure switch assembly is faulty.


Cause Analysis:

1. The pressure transmission pipe is loose or inserted in the wrong position, or the connection with the low pressure port is not strict, there is leakage pressure, the negative pressure is reduced, and the wind pressure switch cannot be closed.

2. The smoke pipe is blocked, the pipe is too long, the angle is too much, the external wind pressure is too large, etc., the exhaust is not smooth and the negative pressure is reduced, and the negative pressure switch cannot be closed.

3. The terminal of the micro switch is oxidized and rusted or the spring is weak and fails. Cause poor contact or no action.

4. The wind pressure switch assembly components are damaged, such as the aging of the diaphragm and the increase of the spring force of the perforation.

Judgment method:

1. Reinstall and adjust the pressure transmission pipe. If the wind pressure switch can work normally, it can be determined that the pressure transmission pipe is the problem.

2. Remove the smoke pipe and test the machine. If the fan switch can work normally, it can be judged that the smoke pipe problem or the external wind pressure is too large.

3. The terminals of the micro switch are oxidized and rusted. When the small shaft of the switch is visually activated, adjust the multimeter to the minimum range of the ohm gear to measure whether the micro switch is closed and connected; if it is not connected, it can be determined that it is a micro switch switch problem.

4. Check whether the small axis of the visual switch is moving; if it does not move, it can be judged that it is a diaphragm or spring problem.


1. Reinstall the pressure transmission tube and clamp it tightly until it does not leak.

2. Remove the clogging debris in the flue, properly shorten the flue pipe, reduce the bending angle, and tighten the windproof device.

3. Use emery cloth to remove the oxide layer or replace the air pressure switch assembly.

4. Replace the air pressure switch assembly, and it is not allowed to adjust the spring force. Because the wind pressure switch has been adjusted according to the design requirements when leaving the factory, and the pressure regulating screw is sealed with glass glue. If the pressure regulating screw is forcibly turned, the seal will be damaged, causing the pressure difference between the left and right chambers to be unable to form, resulting in the inability of the wind pressure switch to operate.



Post time: Nov-14-2022