We stock every part for the Carnes HB Series Steam humidifier ever made. Our technical support team can assist you should you have any questions about your Carnes HB Series Steam humidifier. Order from the source of parts just like the contractors do. Remember to replace your steam tank at least once per year for optimal operation. Most Models will bring up a warning indicator when the steam tank fails. Unfortunately you must view the unit periodically to know when it is time. We recommend you replace the steam tank at least once per year for residential applications and more often for commercial and industrial humidification needs.