Dear muttandjeff,
I do not know if you machine is single or three phase. But whatever, one simple thing is to check that you have the right rotation. If the rotation is good, then fuel can be pumped. Now there must be a sensor that switches on with water flow. No water....no fire. If there is water passing, then the sensor is stuck and showing that there is no flow. The thermostat also opens a solinoid valve in most machines of this type. If solinoid valve is faulty....fuel will not come out. If this is a diesel boiler...check gap of electrodes and condotion of fuel nozzel. One last thing, is something I found in a machine of a friend of mine. I found everything correct....but then I found that the fuel was totaly mixed with water. So, that you have correct fuel, is also important.
fulltech.