IBC Boiler Error Codes: 1, 4, 5, 8, E6 and Lockouts

Tell the fault code from the operating state

The DC and HC controller has two number displays and a light that flashes to indicate a fault, IBC’s controller manual says. The main display carries the fault code. The small service display shows what the boiler is doing.

That second display is where a 4 can mislead. IBC’s table lists service display 4 as trial for ignition and flame proving, a normal step when the burner starts, and 5 as space heating. A 4 there with no flashing fault light is the boiler working.

On the touchscreen boilers there is no number to decode. IBC’s V-10 manual says the bottom line of the screen shows the boiler’s status: green is normal, yellow a warning and red an alarm, and the text in the bar names the condition.

With code 1, check the system pressure

For code 1, temperature too high, IBC’s causes are air in the system, a pump that is not running, and too little flow in the installation, with radiators closed. If someone has shut radiator valves, that belongs in the report. Bleeding air and the pump are technician work.

IBC’s DC and HC user manual says the heating system pressure should not go above 25 psi or below 10 psi in most systems. If it is outside that range, or swings more than 2 to 3 psi, IBC says to contact your qualified service technician. When the boiler is switched off, the main display shows the pressure itself, for example 14P for 14 psi. With code 1 on the display, keep the pump powered and follow IBC’s overheating rule at the top.

With 4 or 5, look at the condensate trap and the vents

Both code 4, no flame signal, and code 5, poor flame signal, list a blocked condensate drain in IBC’s table. IBC’s user manual asks owners to check every month that the condensate trap is full of water and to look at its outlet pipe. Report anything you see rather than taking it apart.

Code 5 also lists the combustion air and flue piping and their terminations. IBC’s DC and HC user manual says that in areas of high snowfall, users must check the side wall exhaust vent and air intake terminations regularly so they do not block.

The rest of IBC’s list for 4 and 5 is gas pressure, the gas valve and its adjustment, power to the gas valve and ignition unit, the ignition gap, the ignitor and its cable, and grounding. IBC’s controller manual says the ignition trial is repeated 4 times before a hard lockout, and the Reset button then allows another attempt. Pressing it does not fix the cause.

Open the Error Logs, and clear errors only after the fix

IBC’s V-10 manual says that when errors occur, an Error Logs button appears on the Home screen, and each log has a Details button. IBC’s SL G3 user’s manual lists checking the Error Logs in its annual maintenance. Photograph the details for the technician.

IBC says to use Clear Errors once the errors have been rectified. It makes the controller check again whether an error is still there; it is not a repair.

Selected errors from IBC’s V-10 troubleshooting tables:

For Ignition Trials Exceeded, IBC says to consult a service technician if the error recurs. The manual also warns never to try to repair the control module.