A human error was the problem!
A loose connection at the fan box that was causing it to intermittently turn on or not turn on at all, had finally caused a board to blow up and shut the whole thing down.
After contacting our Masterton Site Supervisor and asking for a quick resolution, Temperzone technician came in 2 days later and resolved the issue.
Now the panel shows correct temperature, cools, as well as heat the house like before, within 5 minutes.
Glad it finally got resolved after 4 weeks and 4 technician visits.
