A capacitor will read open after a short period of
charging, you should see (with the meter set on the OHMS scale) a gradual increase in resistance until it's charged. To double check, discharge the caps with a screwdriver across both terminals and
plug the meter in again. This will catch about 90% of bad caps, but I don't think these are your problem, probable more along the lines of the water flow, or even the heat/cool shuttle valve stuck between heat and cool. Try turning on the heat again, let it run for a minute, turn the unit off for 10 minutes, then switch on to cool.