Emergency Heating Repair

Oil-fired boilers — Weil-McLain WGO Series 4

The Weil-McLain WGO Series 4 is a cast-iron, oil-fired water boiler approved for Beckett (AFG or CF375), Carlin (EZ), or Riello burners, according to Weil-McLain's own product page. The boiler itself has no digital display — whatever burner is bolted to it does the reporting. That means two WGO boilers installed a year apart, by two different contractors, can show completely different lights or codes depending on which burner control came with them.

• Check that the thermostat is set to heat and a few degrees above room temperature.
• Check the emergency switch at the top of the basement stairs and the separate switch on the boiler itself — both look like ordinary light switches and are easy to bump off.
• Check the oil tank gauge. A boiler that ran dry needs the burner re-primed by a technician, not just a fuel delivery.
• See the next section for what the burner's own control lights mean.

Oil burner primary controls — Beckett GeniSys

Many oil burners on Weil-McLain and other cast-iron boilers use a primary safety control such as Beckett's GeniSys 7575, mounted directly on the burner with a reset button and three small lights. Those lights are the only diagnostic information most homeowners will ever see on an oil system.

Gas-fired condensing boilers — Burnham Alpine (Sage2.X control)

The Burnham Alpine high-efficiency condensing gas boiler, sold today under the U.S. Boiler Company name, uses a Sage2.X control with its own screen and a blinking Help button. U.S. Boiler's service manual splits problems into soft lockouts, which the boiler clears automatically once the cause is gone, and hard lockouts, which need a manual reset after the underlying issue is fixed.

Combi (tankless) boilers — Navien NCB-E

The Navien NCB-E combines space heating and on-demand hot water in one unit and reports trouble as a three-digit E-code on its front panel. Navien's own troubleshooting chart lists more than twenty codes; the ones below are the situations we see most often in the field.

Cold-climate heat pumps — Daikin Aurora (FTX-WMVJU9 series)

Daikin's Aurora wall-mounted heat pump is rated by the manufacturer to heat down to 5°F standard, or -13°F to -25°F with factory options — the cold-climate performance that matters for a Maine winter. It has no screen on the indoor unit; instead, the operation light blinks in a pattern and the remote control can display a short self-diagnosis code.

• To read the code yourself: hold the temperature-down button on the remote for about 5 seconds until a small icon blinks, then press it repeatedly while pointing the remote at the indoor unit — a long beep confirms a matching code.
• If the operation light is on steady with no blinking, the unit is usually protecting itself from a brief power dip or blocked airflow and will often restart on its own in a few minutes.