voltage too low to one heat zone?

h0neywell

hi. ive got 3 heat zones. one day out of the blue 1 zone stops working. the 2 that <span style="text-decoration:underline;">are</span> working read 27V at the thermostat. the one that does <span style="text-decoration:underline;">not</span> work only reads ... well ... sometimes 19V and sometimes 21V at the thermostat - as well as at the beginning of the wire that goes <span style="text-decoration:underline;">to</span> that thermostat. from this i am assuming the boiler works and the transformer works.



my guess is that theres just a poor connection ... somewhere ... any other ideas greatly appreciated. thanks.