After a recent battery change the ACC display starts flashing aprox. 30 secs. after eng. is started, then clears ok after a further 30 secs. I presume it's telling me there is or was a fault/code. How can I clear the fault/code? The heater and blower work good.

The fault detected was the loss of power when you disconnected the battery. If everything is working the way it should, leave it alone. After a certain number of ignition cycles, (off/on) and the control does not detect anymore faults, the flashing should stop.

Thanks for your info, but it's been two weeks since the battery change, should it have cleared by now?

Does the display correctly indicate both outdoor and interior setting temperatures?

Thanks 'blue bowtie' you might have hit on it. The external temp has started to read 110f when temp is actually only around 80f. I'll change external temp sensor and check back. Was ok till battery change but might be just a coincidence.

Thanks to you guys for the info. A new ambient temp. sensor did the trick, the flashing display cleared after a few days & the heater is working good. :)