Precise Air Pressure Sensing Single Port Wind Air Pressure Switch Safe Smoke

Product Specification

Precise Air Pressure Sensing Single Port Design Wind Pressure Switch Safe Smoke Protection

Product Overview
This differential air pressure switch is an essential safety spare part for tankless gas water heaters and wall boilers. It monitors exhaust wind pressure in real time through the pressure guide tube connected to the flue fan. When the exhaust fan works normally, wind pressure pushes the internal diaphragm to close the switch circuit, allowing the water heater to ignite and burn. If the flue is blocked, fan broken or wind pressure abnormal, the diaphragm resets and disconnects the circuit to cut off gas supply, preventing toxic flue gas backflow indoors. Adopting high temperature resistant plastic housing and calibrated 39/55Pa differential pressure, it is a universal aftermarket replacement part to fix ignition failure and random flameout faults of gas water heaters.

Main Advantages
Reliable Flue Exhaust Safety Lock
Detect abnormal exhaust pressure in milliseconds, cut off gas supply to eliminate carbon monoxide poisoning hidden danger, core safety component for gas appliances.

Factory Pre-calibrated Pressure Parameter
Uniform 55/39Pa standard pressure value, no manual adjustment required after installation, consistent sensitivity with original factory parts.

Heat Resistant & Durable Outer Shell
High-grade ABS plastic resists heat and flue gas corrosion, will not deform after long-term installation near the exhaust fan.

Easy DIY Installation & Replacement
Built-in metal mounting lug with reserved fixing hole, standard air pipe nozzle, plug and install without complex wiring or adjustment.

Wide Compatibility
Suitable for 12L-16L household instant gas water heaters running on natural gas or LPG propane.

Stable Long Service Life
Elastic silicone diaphragm inside maintains stable elasticity after repeated pressure changes, low failure rate for long-term use.

Installation Tips
Connect the silicone pressure guide tube tightly to the air nozzle of the switch to prevent air leakage.

Fix the switch on the reserved bracket inside the water heater with screws to avoid vibration shifting.

Do not bend the pressure tube sharply to block air flow and affect pressure sensing.

Test ignition function after installation; if the machine still fails to ignite, check for blocked flue or broken fan.

FAQ:
What is the main function of a single-interface air pressure switch?
 Answer: Its core function is to detect whether the flue has normal draft; if the draft is insufficient (such as flue blockage, fan failure), it will cut off the gas supply immediately to prevent exhaust gas backflow and CO poisoning.

What is the normal service life of a single-interface air pressure switch? 
 Answer: Under normal use and regular maintenance, the service life is 4-6 years; it will be shortened in harsh environments (such as humid, dusty, or poor ventilation).

What will happen if the single-interface air pressure switch fails? 
 Answer: The water heater will fail to start, or flame out suddenly during operation; in severe cases, exhaust gas backflow may occur, causing safety hazards.

Why does the single-interface air pressure switch need to detect negative pressure?
 Answer: For forced draft water heaters, the fan extracts air from the room and discharges exhaust gas, forming negative pressure in the flue; detecting negative pressure can confirm that the fan is working normally and the flue is unblocked.

Can I install the single-interface air pressure switch myself? 
 Answer: It is not recommended. Installation requires familiarity with the water heater's air circuit and circuit, and professional technicians should operate it to avoid incorrect installation leading to faults.