Product Information
Throttle disc
Compatible with 16 equipment models
- KBR21 Bosch Greenstar KBR21 Floor Boiler
- KBR28 Bosch Greenstar KBR28 Floor Boiler
- KBR35 Bosch Greenstar KBR35 Floor Boiler
- KBR42 Bosch Greenstar KBR42 Floor Boiler
- KWB28 Bosch Greenstar KWB28 Floor Boiler
- KWB35 Bosch Greenstar KWB35 Floor Boiler
- KWB42 Bosch Greenstar KWB42 Floor Boiler
- ZBR21 Bosch Greenstar ZBR21 Wall Boiler
- ZBR28 Bosch Greenstar ZBR28 Wall Boiler
- ZBR35 Bosch Greenstar ZBR35 Wall Boiler
- ZBR42 Bosch Greenstar ZBR42 Wall Boiler
- ZWB28 Bosch Greenstar ZWB28 Wall Boiler
- ZWB28-3A Bosch Greenstar Pro ZWB28-3A Wall Boiler
- ZWB35 Bosch Greenstar ZWB35 Wall Boiler
- ZWB42 Bosch Greenstar ZWB42 Wall Boiler
- ZWB42-3A Bosch Greenstar Pro ZWB42-3A Wall Boiler
Please note: Hydrowest Products Ltd. is a wholesale distributor and sells exclusively to licensed contractors and trade professionals.
Fast Shipping
In-stock orders ship within 1 business day to anywhere in Canada.
Code-Compliant
All products meet Canadian HVAC and gas code standards.
Wholesale Pricing
Trade pricing for licensed contractors. 40+ years in the industry.
The throttle disc is a precision replacement component that meters combustion and fan-inlet airflow in Bosch gas-fired appliances, helping to stabilize burner ignition and maintain correct primary-air and fan performance. Offered as a service part in Bosch parts catalogs, these thin formed discs come in multiple bore diameters to match specific models and install into the throttle/air‑limiter assembly for routine maintenance or repair. (bosch-homecomfort.com)
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