The motor thermistor is indicating over temperature, If this is a older unit and just started to error, check your valve adjustment. They need to run into the floor quick. Check your motor for overheat. If it's wye-delta, time for a quick transfer and check contacts and motor connections. If the valve and motor is fine, and you have high traffic, this is a sales opportunity for a cooler. We installed many oil coolers on the holeless units.
