White-Rodgers All-Spark 50D50U Error Codes: E02 to EC1

By Ray Bennett · Updated 2 October 2026 · 4 min read · Checked against the maker’s manual

White-Rodgers All-Spark 50D50U Error Codes: E02 to EC1

Short answer

The White-Rodgers All-Spark 50D50U is a universal spark ignition module with a three character display. ht means a flame is on and FLo a weak flame. E02 means no flame during the trial for ignition, E03 the flame went out while running, E04 flame out of sequence, E05 the vent damper, E06 the fuse and E08 the 24 volt supply out of range.

The White-Rodgers All-Spark 50D50U-843 is a universal 24 volt spark ignition module. It replaces the original module on gas appliances with intermittent pilot or direct spark ignition, and White-Rodgers’ reference card says it replaces more than 1,000 part numbers. It comes set up like a Honeywell S8610U, and it shows what it is doing on a three character display.

Everything on this page comes from White-Rodgers’ own installation instructions for the 50D50U-843, published by Copeland. Because this module replaced the original, any code chart on the appliance itself was written for a different part. Use this list.

Before you start

What to carry: a torch and a pen. Ten minutes.

Gas or electric? Gas, with spark ignition, running on 24 volts.

Check it is this module. 50D50U-843 and All-Spark are printed on it. For the White-Rodgers furnace board with a similar display: the 50M56X codes.

A blank display. White-Rodgers calls it an internal module error. Wait for the module to reset, and replace it if the problem stays.

Where you stop. E04: flame sensed out of sequence. White-Rodgers says to check the ignition source, the gas valve and the flame probe. Turn the gas off and call a technician.

E11: gas valve on when it should not be. White-Rodgers says to check the gas valve. Turn the gas off and call a technician.

E05: the vent damper. White-Rodgers says to check the vent damper and its connections. That is a job for a technician.

What the display means

The All-Spark codes grouped by what they point at. E04 and E11 are the two to stop at.

Check 1Free, two minutes

Read the status codes

hPr, hIP, hPo. A call for heat during the pre-purge, between spark tries, and in the post-purge after the call ends.

tFI. The trial for ignition, the time the module sparks to light the burner.

ht. A call for heat with the flame on. Normal.

FLo: a weak flame signal. White-Rodgers says to check the flame probe, and clean or replace it: how to clean a flame sensor safely.

The error codes

Code	What White-Rodgers says
E00	Loss of IRQ signal: recycle power, replace the module if it persists
E01	Pressure switch open
E02	No flame during the trial for ignition
E03	Flame out during run
E04	Flame sensed out of sequence
E05	Vent damper error
E06	Fuse open: replace the 5 amp ATC fuse
E08	Wrong 24 volt supply, it must be over 18 and under 30 volts AC
E09	Pressure switch stuck closed
E10	Air temperature sensor error, integrated thermostat only
E11	Gas valve on when it should not be
E12	Gas valve off when it should not be
E13	TH-W or limit open, integrated thermostat mode
E22	Gas valve off lockout: it waits, then restarts itself
EE1	Pressure switch terminal miswired
EC1	Connectivity error: recycle power

The checks that are yours

Check 2

Work the owner checks

E02 and E03: the flame. White-Rodgers says to check the ignition source, the gas valve and the flame probe. Start with the gas being on at the appliance: why a gas appliance will not light.

E06: the fuse. White-Rodgers’ answer is a new 5 amp ATC fuse. A fuse blows for a reason, so have the 24 volt wiring checked if it goes again.

E08: the supply. White-Rodgers says the 24 volt supply must be over 18 and under 30 volts AC, and to check the supply voltage source.

E01 and E09: the pressure switch. White-Rodgers says to check the pressure switch connection: the places a pressure switch fault hides.

Reading and clearing the history

Three holds of the same two buttons: read the history, clear it, or unlock the settings.

Check 3Free, five minutes

Use OPTION and SELECT

Read. In standby, hold OPTION and SELECT together for two to five seconds. FLt appears after two seconds, then the stored codes. Press OPTION for under a second to step through them. Eno means none are stored.

How much it keeps. Up to five codes, for up to 14 days. White-Rodgers says codes on systems powered through TH-W do not expire.

Clear. Hold both buttons for five to ten seconds until CLr and FLt alternate, then let go. CLr flashes three times when the history is erased.

Settings lock. White-Rodgers says the settings lock after 10 calls for heat in a row. Holding both buttons for 10 to 20 seconds unlocks them, shown by UnL. That is for the installer.

While you do it. White-Rodgers says a call for heat is ignored while the module is in these menus.

Questions people ask

What does E02 mean on a White-Rodgers All-Spark?

No flame during the trial for ignition. Check the gas is on, then White-Rodgers points at the ignition source, the gas valve and the flame probe.

What does E03 mean?

The flame went out while the appliance was running. White-Rodgers gives the same checks as E02: the ignition source, the gas valve and the flame probe.

What does FLo mean?

A weak flame signal. It still runs, but White-Rodgers says to check the flame probe and clean or replace it.

What does E06 mean on a 50D50U?

The fuse is open. White-Rodgers says to replace the 5 amp ATC fuse. If it blows again, have the 24 volt wiring checked.

What does E08 mean?

The 24 volt supply is out of range. White-Rodgers says it must be over 18 and under 30 volts AC.

How do I see the stored codes?

In standby, hold OPTION and SELECT together for two to five seconds. Up to five codes play back, and Eno means none are stored.

Sources: White-Rodgers (Copeland) installation instructions 37-7822004 for the All-Spark 50D50U-843 24V non-integrated spark ignition module, and the White-Rodgers furnace controls reference card R-4952