OpenTherm Gateway Arduino Shield from Jiří Praus on Tindie
OpenTherm - Tasmota
OpenTherm Adapter - Hobby Projects
Worcester Bosch and OpenTherm – MyBoiler.com
Adapter OpenTherm ml 724 for connecting to a digital bus smart home intelligent home heating control WI Fi management GSM management management by GPRS smart home controller|Home Automation Modules| - AliExpress