We have three zones and one pump is not warm. It feels like the others that it is running, but the water in the loop affected is not heating. It may not be calling for heat but it is on the same thermostat as another pump and that one is heating. Any ideas?

These pumps work by timer and by thermostat.
I prefer timer-operated over thermostat because I use hot water at predictable times, thus cutting operation cost to a fraction.
http://waterheatertimer.org/Water-heater-recirculation-system.html

When my first re-circulation system stopped working, I took it off and cleaned it out, but it never started working again.
I also tried to take it apart to see if motor was repairable.
My electric motor guy told me that when motors slow down or stop rotating that they overheat and burn out.
I asked him about rewinding the motor, and he said in the old days, every motor was repaired and put back in service, but today they throw motors away. All that copper goes into the landfill for tomorrow's prospector. And he said what I noticed, that the pump assembly doesn't come apart for repairs.

You can remove the pump and try same things I did, but my guess is you need replacement.
I bought new pump from Lowes.
Local plumbing shops carry re-circulation pumps, and plumbers and handymen install them.
Installation is simple enough if you're handy and peripherally experienced with plumbing.
Grundfos instruction manual with photos:
http://waterheatertimer.org/pdf/Grundfos-L-UP-TL-043-install-photos.pdf

Add a comment for more free assistance.
Also take advantage of fixya phone service.
For a price, fixya expert says same thing shown above, and can help you install new one via phone.