Product review (1 stars): Tried two of these - neither worked properly
The first unit would would not stop sparking, even though the probe was in the flame and glowing red hot.  This must be a frequent problem because the instructions specifically address it, telling you to check grounding of the module unit and the pilot.  This was triple checked as good.  I even ran double grounding wires to both.  Ground was confirmed as good, even tried grounding to gas pipe.  Called tech support and they thought I must have a defective unit so I ordered another one and got same result.  After second failure, had extensive discussion with Robertshaw tech support and they were clueless.  Very disappointed as I cannot find a similar product.