mjenergy
New Member
My 8 Zone radiant floor heating system is controlled by 2 Taco ZVC404-EXP Controllers. One is the Master and the other one is the Slave. The system is 3 1/2 years old and has been working fine up until last week. I noticed that some of the zones were not heating properly. After further inspection here is what I found:
Master: Zone 1 is not working properly. When Zone 1 calls for heat, the boiler starts, the zone valve opens, but the circulating pump does not run. When zone 2, 3 or 4 call for heat, the boiler starts, the zone valve opens and the circulating pump starts running (they are working properly).
Slave: Zones 2, 3 & 4 are not working properly. When Zone 2, 3 or 4 calls for heat, the boiler starts, the zone valve opens, but the circulating pump does not run. Zone 1 is working properly. When zone 1 calls for heat, the boiler starts, the zone valve open and the circulating pump starts running.
Are both controllers bad and need to be replaced? Thanks for your help.
Mark
Master: Zone 1 is not working properly. When Zone 1 calls for heat, the boiler starts, the zone valve opens, but the circulating pump does not run. When zone 2, 3 or 4 call for heat, the boiler starts, the zone valve opens and the circulating pump starts running (they are working properly).
Slave: Zones 2, 3 & 4 are not working properly. When Zone 2, 3 or 4 calls for heat, the boiler starts, the zone valve opens, but the circulating pump does not run. Zone 1 is working properly. When zone 1 calls for heat, the boiler starts, the zone valve open and the circulating pump starts running.
Are both controllers bad and need to be replaced? Thanks for your help.
Mark
