[smquandt]

I have an AHE-120-04X.  The Diesel side runs intermittently, electric side always works.  I carry a spare control box and have installed the new spare with the same results.  I can hear clicking which sounds like relays (might be the fuel solenoid) opening and closing but the burner does not start.  If I very lightly tap either control box the motor starts and the burner lights. It may go through 10-15 cycles then fail to light, tap and it works.  Hesitant to declare both control boxes bad as the spare is new.  Does anyone have any ideas?