Safe and automatic ventilation monitor

Enjoy a gorgeous flame picture without worries

When ventilation systems and fireplaces are used at the same time, dangerous flue gases may enter the room containing the fireplace. Our S-USI II vacuum switch interface is a smart vacuum monitor and ensures continuous monitoring of the air pressure situation to keep everyone in your home safe.


The advantages of the S-USI II

  • Safety during simultaneous operation of ventilation systems and a fire
  • Monitoring of the reliable pressure ratio between the chimney and the room with the fire
  • Confidence in your safety thanks to the fully automatic functions
  • Easy to operate


S-USI II is available for all Spartherm built-in and freestanding wood fires

Build in fire with double-sided fire view.
Maximum view of the flame picture
A unique and beautifully rounded wood fire.
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