Vaillant Ecotec boiler. Central Heating will not turn on. Water heating is ok. Error code S.30 is being reported. New batteries in remote ccontroller, receiver has green light. No other discernible issues
Heating & Cooling - Honeywell - Programmable Thermostat Heater
Answers & Comments
No heat demand from external controls clamp 3-4open ,its on the error codes in the hand book or you can down load one from there web site