My Foxwell unit also showed pump activation and realtime rpms. Those seemed normal, but when I feel the pump with my hands im pretty sure there is no vibrations. Its at least very very weak. As said before, it is easy to feel the vibrations on the the pump easily excessible on the right side (which is not in the PTC circuit).Yes, the Foxwell unit you have will show the pump activation and real time rpms, which is how I eliminated it as the issue on mine. I’m still going to check the continuity on the sensor. I saw on another post that if the sensor reads anything below -20F, it shuts the heater down to protect the pumps, etc from liquid freezing. That makes sense as there are no sensor resistance values below that temp. I’m still wondering about those -40F readings we both saw. Even if the sensor was throwing that valve intermittently, it would still shut the system down or at least cycle it. I’ll post when I check the continuity on mine.
Should there be just as strong vibrations from both?