Baxi error E87
Has anybody come across this type of fault.
I have a Baxi combi 836 (not combi 2) which was wired to a Tado thermostat controller (opentherm and relay) to enable me to switch from opentherm to relay and vice versa, incase of any communication problems. I have always used opentherm but would like to have a Baxi wall mounted weather unit installed which needs the use of relay, so I tested the switching of D01 to R01.
The above operation produced a flashing E87 error (lost communication) on the Baxi and set its own CH temperature to 60 when rotating the CH dial. The Tado temp was actually set to 50 degrees. Tried a basic room on/off thermostat which produced the same results even after re-powering the boiler. (Error 87 cannot be reset).
Switched back to D01 setting and opentherm controlled boiler burst into life.
Looks like the boiler is retaining its opentherm settings and retaining its low voltage settings instead of switching to 240v switched live.
Gas guy wired everything correctly in the boiler as I monitored that.
Help would be greatly appreciated. thanks.