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LCD
Hi have just installed a new Vaillant Ecotec Plus 831. Normally when I wire in a Honeywell CMT 927 programmable room stat. to the Ecotecs, it is straight forward, however, Vaillant have changed their internal wiring. Although the Honeywell receiver is picking up the signal, the boiler is running on heating constantly. I phoned Vaillant but they didn't answer after 15 mins, phoned Honeywell. The guy was really helpful, he said to put a link between the 2nd Live and A on the receiver, and just have B wired to the 230V RT on the boiler. Well, I did this and the boiler still just ran constant on heating, disregarding the programmer. The little green light clicks on the receiver when I increase the temp, however the boiler still runs on heating continuously prior to this. Somehow I think these boilers have become too complicated, or they're being produced for computer experts to install. Anyway, I'm hoping someone on this forum has encountered the same problem and can explain the wiring for 230V external controls.