{"title":"Pressure Sensors \u0026 Switches","description":"\u003cp\u003ePressure sensors and switches for HVAC, ventilation and control systems. From ZZ Marts, Karachi and Lahore, with nationwide delivery.\u003c\/p\u003e\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\u003ch3\u003eHow much does an air pressure switch cost in Pakistan?\u003c\/h3\u003e\u003cp\u003eAt ZZ Marts, the KFR-1 air pressure switch for gas water heaters and boilers costs Rs 950. The adjustable air differential pressure switch for HVAC ducts costs Rs 2,400 to Rs 3,500, depending on the pressure range you choose.\u003c\/p\u003e\u003ch3\u003eWhat does the air pressure switch in a gas water heater do?\u003c\/h3\u003e\u003cp\u003eIt proves that the fan or flue draught is working before the heater ignites. The KFR-1 switches its changeover contact (NC \/ NO \/ C) at about 39\/55 Pa (0.9 mbar), with a maximum of 10 mbar. Before ordering a replacement, check the pressure rating and port layout against your original switch.\u003c\/p\u003e\u003ch3\u003eWhat is an air differential pressure switch used for?\u003c\/h3\u003e\u003cp\u003eIt measures the difference in air pressure between two points and switches a contact when the pressure you set on its dial is reached. It is used on HVAC ducts, air handling units, fans and filter monitoring, and needs no separate power supply to operate the contact.\u003c\/p\u003e\u003ch3\u003eWhere can I buy pressure switches in Karachi and Lahore?\u003c\/h3\u003e\u003cp\u003eFrom ZZ Marts (Zam Zam Traders), with stores in Saddar, Karachi and Garhi Shahu, Lahore, and delivery across Pakistan. If you are matching a part, send a photo of the old switch on WhatsApp before ordering.\u003c\/p\u003e","products":[{"product_id":"air-differential-pressure-switch-hvac-duct","title":"Air Differential Pressure Switch – Adjustable HVAC Duct Switch","description":"\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMultiple Adjustable Ranges from 20 Pa up to 5000 Pa\u003c\/li\u003e\n\u003cli\u003eScaled Dial Under Clear Cover for Quick Setting\u003c\/li\u003e\n\u003cli\u003eSenses Differential Air Pressure Across Two Ports\u003c\/li\u003e\n\u003cli\u003eSwitches an Output Contact When the Set Pressure Is Reached\u003c\/li\u003e\n\u003cli\u003eDuct Air-Pickup Probe and Sensing Tubes Included\u003c\/li\u003e\n\u003cli\u003eSurface \/ Wall Mountable Housing with Fixing Tabs\u003c\/li\u003e\n\u003cli\u003eCable Gland Wiring Entry\u003c\/li\u003e\n\u003cli\u003eDiaphragm-Type Mechanical Design\u003c\/li\u003e\n\u003cli\u003eIdeal for HVAC Ducts, AHUs, Fans and Filter Monitoring\u003c\/li\u003e\n\u003cli\u003eNo Separate Power Supply Needed to Operate the Contact\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eProduct Description\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eAir Differential Pressure Switch\u003c\/strong\u003e is an adjustable pressure switch used to monitor the difference in air pressure between two points and switch an electrical contact when a set pressure is reached. Choose the range that suits your application — from 20 Pa up to 5000 Pa — and set the exact switching point using the scaled dial under the clear cover.\u003c\/p\u003e\n\u003cp\u003eIt is designed for HVAC and ventilation systems, where it is commonly used for airflow proving across fans, dirty-filter detection on air handling units, and monitoring duct or room pressure. The unit connects to the airflow through the included duct air-pickup probe and flexible sensing tubes, so it can be fitted to a duct or plenum during installation.\u003c\/p\u003e\n\u003cp\u003eThe switch uses a diaphragm-operated mechanism and a built-in changeover contact, so it does not need its own power supply to operate — it simply opens or closes your control or alarm circuit at the set pressure. The housing is surface mountable using its integral fixing tabs, with a cable gland for tidy wiring entry.\u003c\/p\u003e\n\u003cp\u003eSelect your required pressure range from the options above. Contact rating, ingress protection and exact dimensions are not marked on this unit; if your application needs specific electrical or IP figures, contact us before ordering and we will confirm suitability.\u003c\/p\u003e","brand":"ZZ Marts","offers":[{"title":"20–200 Pa","offer_id":52907586814264,"sku":"CMP-AIR-DPS-200","price":2400.0,"currency_code":"PKR","in_stock":true},{"title":"30–300 Pa","offer_id":52907586847032,"sku":"CMP-AIR-DPS-300","price":2500.0,"currency_code":"PKR","in_stock":true},{"title":"40–400 Pa","offer_id":52907586879800,"sku":"CMP-AIR-DPS-400","price":2550.0,"currency_code":"PKR","in_stock":true},{"title":"50–500 Pa","offer_id":52907586912568,"sku":"CMP-AIR-DPS-500","price":2600.0,"currency_code":"PKR","in_stock":true},{"title":"200–1000 Pa","offer_id":52907586945336,"sku":"CMP-AIR-DPS-1000","price":2800.0,"currency_code":"PKR","in_stock":true},{"title":"500–2500 Pa","offer_id":52907586978104,"sku":"CMP-AIR-DPS-2500","price":2950.0,"currency_code":"PKR","in_stock":true},{"title":"1000–4000 Pa","offer_id":52907587010872,"sku":"CMP-AIR-DPS-4000","price":3100.0,"currency_code":"PKR","in_stock":true},{"title":"1000–5000 Pa","offer_id":52907587043640,"sku":"CMP-AIR-DPS-5000","price":3500.0,"currency_code":"PKR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1012\/3932\/4984\/files\/ChatGPTImageJul24_2026_04_49_03PM.png?v=1788527448"},{"product_id":"kfr-1-gas-boiler-air-pressure-switch","title":"KFR-1 Air Pressure Switch – Gas Boiler \/ Water Heater (39\/55Pa)","description":"\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eKFR-1 Air Pressure Switch (Fixed Setpoint)\u003c\/li\u003e\n\u003cli\u003eSwitching Pressure ~39\/55 Pa (0.9 mbar)\u003c\/li\u003e\n\u003cli\u003eMaximum Pressure 10 mbar\u003c\/li\u003e\n\u003cli\u003eRated 125V ~\u003c\/li\u003e\n\u003cli\u003eChangeover Contact (NC \/ NO \/ C)\u003c\/li\u003e\n\u003cli\u003eTwo Pressure Ports\u003c\/li\u003e\n\u003cli\u003eBracket-Mount Metal Body\u003c\/li\u003e\n\u003cli\u003eFor Gas Water Heaters and Boilers (Flue \/ Fan Proving)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eProduct Description\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eKFR-1 Air Pressure Switch\u003c\/strong\u003e is a fixed-setpoint pressure switch used in gas water heaters and boilers to prove that the fan or flue draught is present before ignition. It switches its changeover contact at around 39\/55 Pa (0.9 mbar), with a maximum of 10 mbar.\u003c\/p\u003e\n\u003cp\u003eThis is a common replacement part for many gas water heaters and wall-hung boilers. Supplied brand-new. If you are matching it to a specific heater, check the pressure rating and port layout against your original before ordering — contact us and we will help.\u003c\/p\u003e","brand":"ZZ Marts","offers":[{"title":"Default Title","offer_id":52912419504440,"sku":"CMP-KFR-1","price":950.0,"currency_code":"PKR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1012\/3932\/4984\/files\/ChatGPTImageJul24_2026_04_46_49PM.png?v=1788870892"}],"url":"https:\/\/zzmarts.com\/collections\/pressure-sensors-switches.oembed","provider":"ZZ Marts | Zam Zam Traders","version":"1.0","type":"link"}