Honeywell Zone Valve makes squeak noise when closing

Squidstro

I had new Honeywell V8043E1012 zone valves installed on a 2 zone hydronic heating system close to 2 years ago.

The zone valves made no noises when closing except the distinct spring closing action that Honeywell zone valves are famous for.

Now this heating season, the upstairs zone valve makes a single squeak as the ball valve is closing after the call for heat stops. It's a metallic squeak. I'm positive the sound is coming from the area of the zone valve.

I'm not sure if it's the valve operation, the power head or actuator, or the plumbing pipe itself.

I used the manual open lever a few times while the call for heat was off. The open and close action just make the spring action noise which is normal. I got no squeak.

To be more descriptive on the sound, it's a single tone, whiny and high pitched. It's definitely as the zone valve shuts after a call for heat. It's only happening to the upstairs zone valve. The downstairs zone valve is still quiet.

I've heard of plumbing making high pitched whiny sounds due to pressure change issues. But keep in mind that this is hydronic heat. The water feed has a 15 PSI pressure reducing valve and the reading on my furnace is just below 20 PSI on the gauge.

Thoughts gentlemen?