expansion module
I recently repaired a light commercial system. Supply line had burst in four places (improper shut down last year). After the line repair, I activated the controller - Hunter Pro Series 300i - and zones 1,2 and 3 worked fine. Zones 4,5 and 6 which are hooked up to an PCM300 expansion module did not come on. I disconnected the zone 3 wire and one at a time, I hooked up zones 4,5 and 6. Each of the non operating zones worked when attached to zone 3. This leads me to believe that there is no problem with the wiring or the valves for zones 4,5 and 6. I believe that the expansion module needs replacement. Is there anything else I can do to prove this, before replacing the expansion module.
