The test results have been released as a technical bulletin on the Worcester, Bosch website confirming the compatibility. The full bulletin reads:
Worcester, Bosch can confirm that we have tested for any detrimental effects that the EndoTherm energy saving additive may have on the internal water-facing components and seals on the primary heating circuit side of Worcester boilers.
As a result of this we can confirm that EndoTherm will not adversely affect any components of a Worcester boiler, or affect the associated warranties.
Worcester, Bosch is not able to confirm the energy saving performance claims of EndoTherm, but allow the use of this product in terms of compatibility, when used with a Worcester boiler in a sealed, wet heating system.
This bulletin is available on the Technical Bulletin section of the Worcester, Bosch website where all the latest information and updates are shared about Worcester, Bosch products. A direct link to the Technical Bulletin is available here: Technical Bulletin TB 0125 A (02/2018) – EndoTherm Compatibility