Quote Originally Posted by kevinsmart View Post
It looks like the HCE80 works fairly autonomously apparently calculating and responding to zone demands itself.

For instance you will see it opening actuators for zones even when the Evotouch controller reports 0% demand.

Which explains why the HCE80 controlled pump runs even when there is no boiler demand.
I agree, the HCE80 does seem to work too autonomously.

Seen as the HCE80 was from a time before the evohome controller, I just don't think there is the software and/or hardware in it that enables it to sync it's cycle rate with that of the evohome.