Over time build up can occur in the heat exchanger causing restrictions that can cause overpressure and/or leakage. In some cases the exchanger can be flushed and use can continue but usually it will need to be replaced. Gruber does supply plate sets to allow you to rebuild the heat exchanger, and we also have a rebuilt heat exchanger program to allow you to trade your heat exchanger with a rebuilt one.
The 3-Way resin delivery/recirculation valve sometimes developes buildup on the ball valve. Cleaning the valve will usually solve this problem.
Alarms and shutdowns are often caused by an increase resin pressure tripping the pressure sensor. Often this is simply caused by a cool down in the weather or change in the resin formulation causing a higher viscosity. This can often be acomedated by adjusting the pressure sensing device, however be sure there is not a blockage of other problem first. Take care not to over adjust preventing protection from extreme pressures caused by blockages or heater corrosion. For Resin Sensor adjustments refer to the FAQ How do I adjust the Resin Pressure in my Autocaster or Batchmaster?