FVI 12 Pressure test is the same as the 5 and 10.

FVI 12 E CODES

ALWAYS DISCONNECT ELECTRICAL POWER

BEFORE REMOVING FRONT PANEL!

• E0 this code means the unit lost power as it was in operation. Cause could be a thunder storm.
• To fix this. Turn water off and back on again.
• E1 This could be a couple of issues; one (gas valve not open fully) or (flame sensor not detecting fire).
• To fix this. Check gas type on side of unit to make sure it is a proper application (IE) natural gas or propane, Adjust gas knob clockwise to highest setting.
• E2 Shut Gas off, Check for leak.
• E3 Check amount of gas going to unit. Gas is to be 7 inches of water column for natural gas, and 11 inches for Propane. NOTE 1PSI is equivalent to 27 inches of water column.
• E4 temperature sensor, loose connection or faulty sensor.
• To fix this Look toward the bottom left; you will see a black and blue wire that is screwed in to the outgoing water pipe. Check where the wires connect between that sensor and the computer (Computer is the black box at bottom right side) If this does not fix the issue. This part needs to be replaced.
  • E5 Over temp sensor has remained in an open position.
  • To fix this. Location is at top left there are 2 white wires connected to a circular sensor on an elbow (PIPE) coming out of the heat exchanger. First disconnect then reconnect the wires just in case there is a bad connection. If this does not fix it. You will need to override that switch. To override the over temp sensor, you disconnect the two wires and touch them together. Turn the hot water on and see if this takes care of the issue.
  • E6 Check vent pipe for anything that might be clogging airway. The next possible solution is going to be the air diaphragm. WARNING UNPLUG UNIT BEFORE PERFORMING THIS PROCEEDURE. To locate the air diaphragm; look toward the top left there are 2 wires attached one is black and the other is blue. If you look at the left side of the diaphragm you will see two screws that keep it attached to the back of the cabinet. You will need to remove this from the cabinet in order to get to the white nylon screw on the right side of the diaphragm. Turn that screw out (left) only a ¼ turn at a time and check to see if the E6 is still on the display.
  • E7 Check vent pipe for anything that might be clogging airway.