This is most likely going to end in a service call
but a few questions before I get on the phone.
Starting up a new Aquabalance 120 C combi boiler, the system goes through its "FH" purging cycle but then I get "A 16" error, "Outside sensor is not connected". The sensor is connected.
I've used a multimeter to check its wiring, no resistance from point to point.
I've checked the two fuses, both are intact.
Note that the sensor is apparently optional but changing the "OTC exempt" setting has no effect.
Ultimately I probably need a service call, but do I need a special kind of technician to be able to diagnose this fault? It seems like the worst case is to replace the control board.
Should I call Weil-McLain?