The heat in our four zone house is working except for one zone. Digital Honeywell THermostat lights up when programmed, little flame picture appears and click noise is heard, just like other thermostats, but no heat in that zone. Any ideas what is wrong or how to fix. Thanks

Forced air or boiler system?

Boiler system

Could be
Air in the line.
Defective zone valve or power head.
Low water pressure in system
Defective relay to activate pump

Check out all of these then post back.

What type of zone valves do you have. Taco, Honeywell? There should be a lever on the zone valve that will allow you to manually open the valve. Turn a thermostat up in a portion of the house that is getting heat, then manually open the zone valve to the part of the house that isn't getting heat. Let me know what you find, and we will take it from there.

@mygirlsdad77
I'm having the same problem as stated above, I have FHW gas w/ Taco, when I open the valve manually and turn up the other thermostat, I get heat all through, though I am hearing air in the system and trying to bleed it out. I can't get the second zone to work on it's own.

Sounds like you need replace the taco valve head assembly, and possibly the internals of the valve body, or just replace the complete zone vavle and you should be set.