My Mitsubishi ASHP was installed last year, to run the existing radiator CH system. An extension with UFH was about to be built and the installers left me with a separate pumped connection for the UFH. That has duly been completed and connected and been running by connecting the UFH pump in parallel with the existing CH pump - ie I have one zone.
I now want to separate the CH and UFH into separate zones. I have the contacts from the UFH wiring centre connected to IN6 (Room Thermostat 2 input) and the UFH Pump to OUT3 (Zone 2 space heating).
I have turned on DIP switches SW2-6 and SW2-7 but keep getting an L5 error (Indoor FTC temperature thermistor reading incorrect value, thermistor disconnected or wired into the wrong connection on the board, incorrect dip switch setting on the FTC board). The manual tells me I don’t need an indoor thermistor if I’m using the remote wireless controller. I have also tried changing SW3-1 and SW4-1 but still get an error code.
With SW2-6 and SW2-7 on, the controller shows 2 zones under the Heat Pump symbol but then goes into the error mode.
What am I doing wrong? Any help much appreciated.
