[bobboV]

Hi, I live in a condo with water based heating and AC. I woke up to a loud ticking or panning noise coming from the AC unit. Unfortunately there is no model number on this unit as the painter sprayed over the tag. I believe its called a Climetec fan coil unit.

I removed the cover and the noise is coming from a Honeywell VC4011-12 valve actuator which is continuously cycling on and off. I can turn off the AC at the thermostat, or close the manual water valve but no relief.. it just keeps hammering away. It stops when I turn power off to the whole AC unit.

Is the valve defective? Or could this be a symptom of some other problem?

Thanks
Bob

[bitters]

It could be a defective valve, but most likely it's the voltage opening and closing the valve. Check all the connections. Then take the stat off and see if it stops.Then jumper from R to Y and see if the valve opens.

[bobboV]

Thanks for responding bitters. I checked all connections last night and all was good. I was able to take the "head" off the actuator and while I could feel it on there was no cycling. I also heard no clicking from any relays. So I assumed it was the valve. What also bothered me is I found a splice in the wiring last night so it was replaced once already.. and the building is only 8 years old. Fortunately the regular hvac technician for this building was available. Turns out the actuator was defective. Apparently the Honeywell VC4011-12 actuators in these Climetec fan coil units have been failing prematurely. He replaced it with a different make. Both the head and the body. This new actuator has a screw valve whereas the old one just moved up and down. All's good now.