Lambda Sensor NTK. PS/FM/BF/BM. NGK OZA685-WW1 - NGK

Manufacturer Information - NGK:

About NGK

NGK is a leading manufacturer of sensor / switch parts for use in heat and power systems including biomass.

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SKU: SP.00.00135 | Manufacturer: NGK

Regular price List: £163.51 Sale Price: £125.78    Saving: £37.73 All prices exclude VAT where applicable.

Overview: Lambda Sensor NTK. PS/FM/BF/BM. NGK OZA685-WW1 - NGK

Lambda Sensor NTK. PS/FM/BF/BM. NGK OZA685-WW1, manufactured by NGK.

Lambda sensor NGK OZA685-WW1 for Herz Biomass Boilers. Please contact us if you have any questions about this spare part (manufacturers part no. 5010000-192), on When speaking with one of our heat and power product advisors, please mention the following internal part code: SP.00.00135

Lambda Sensor NTK. PS/FM/BF/BM. NGK OZA685-WW1 - NGK is compatible with biomass heat and power systems with boilers made by: Herz



Lambda Sensor NTK. PS/FM/BF/BM. NGK OZA685-WW1, technical information:

Grease-free thread M18x1,5, Hexagonal head 22mm, Fibre glass hose 150mm, 2 x heater cable white AWG20 (0,50mm²) 230mm, -6,1mV Output signal with 13VDC by 21%O2, 80 Ohm Internal resistance, 16V Max. admissible heater voltage, 6,1 Ohm Heater resistance (23 +/- 5°C)

This sensor / switch spare part is manufactured by NGK. Full specification information can be seen in the table below.

Fuel CompatibilityBiomass
System Compatibility

Systems Manufacturer Compatibility

This spare part from NGK is suitable for use with biomass systems from the following heat and power manufacturers:

  • Herz

Specific Boiler Compatibility

The following is a list of boilers we know this spare part to be compatible with. Please note we are still developing our dataset and this list is subject to change without notice.

  • Pelletstar 10
  • Pelletstar 20/30
  • Pelletstar 45/60
  • Firematic 20/35
  • Firematic 45/60
  • Firematic 80/100/101
  • Firematic 130/150/151/180/199/200/201
  • Firematic 249/251/299/301
  • Firematic 349/351/399/401/499/501
  • Biomatic 180/220/250
  • Biomatic 180/220/250
  • Biomatic 300/350/400/450/499/500
  • Biofire 500
  • Biofire 600
  • Biofire 800
  • Biofire 999/1000
  • Biofire 1250
  • Biofire 1500

If you are purchasing Lambda Sensor NTK. PS/FM/BF/BM. NGK OZA685-WW1 for a different system (type or manufacturer) than those outlined above, you may find it useful to speak with our friendly experts who can advise on compatibility and performance.

Sizing & Dimensions
  • Length: 19cm
  • Width: 17cm
  • Height: 2cm
  • Weight: 0.24kg
Main CategoriesCombustion & Heat Exchanger, Electrical & Control, Flue
Sub Category (primary type)Sensor / Switch
Product / Spare PartSpare Part


We are still working on our shipment calculation system. If you have any questions, please call us: 0203 189 0666.

Before ordering this spare part, please take note of the following weight, dimensions and delivery information.

  • Length: 19cm
  • Width: 17cm
  • Height: 2cm
  • Weight: 0.24kg
  • Delivery Type: Courier Pack (Max 5kg)

Please note, if this item is out of stock it can be placed on back order. Please simply order the part as usual and we will contact you with an expected lead time.


Returns for Lambda Sensor NTK. PS/FM/BF/BM. NGK OZA685-WW1 - NGK will be handled in line with our returns policy. All sales through this website are governed by our standard terms and conditions.


This product is covered for a period of 12 months by standard UK regulations, which protect you against defects in the product. Warranties may be invalidated if insufficiently trained personnel attempt to install or commission this product. In the event of a warranty claim, customers will need to provide evidence of training of the persons which handled and installed any products within the claim.

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Need Assistance?

If you require any kind of assistance with your heat and power systems, our sister company Myriad Plantroom Services has a network of highly trained service engineers all around the country that can help you fit this Lambda Sensor NTK. PS/FM/BF/BM. NGK OZA685-WW1 - NGK and any other sensor / switch spare parts by NGK that you purchase today.