Utica Dunkirk E83 Error Code
87 Communication error E92 Combustion test alarm during auto-setting E 1 109 Pre
Source: dcc-115__utdu-dcc-115-dcc-205-dcb-75-dcb-165-iom.pdf
What does Utica Dunkirk E83 mean?
E83 on Utica-Dunkirk DCC/DCB condensing boilers indicates an OpenTherm (OT) communication failure between the boiler's PCB and the connected OpenTherm-compatible room thermostat or controller. The boiler cannot establish or maintain the data link needed for modulating control via the OpenTherm protocol, causing the control interface to lock out or fall back to on/off mode.
Symptoms
- Boiler display shows E83 when an OpenTherm thermostat or service key is connected
- Boiler may operate intermittently or fail to modulate correctly
- OpenTherm thermostat displays a communication or boiler error
- Fault clears temporarily after power cycle but returns
Common causes
- Loose or swapped OpenTherm wiring at the boiler terminals or thermostat
- Short circuit on the OpenTherm communication wiring
- Defective or incompatible OpenTherm thermostat or service key
- PCB OpenTherm interface failure
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Diagnostic steps
Check OpenTherm wiring connections
Inspect terminals 1–2 (OpenTherm bus connection) on the boiler PCB. Ensure wires are firmly seated, not reversed, and free of nicks or shorts.
Remove power and reseat connectors
Power down the boiler completely, unplug and re-plug the OpenTherm harness at both the boiler and thermostat ends, then restore power and check if E83 clears.
Test with a known-good thermostat or bypass
Temporarily disconnect the OpenTherm thermostat and install a standard on/off thermostat across the TT terminals. If the boiler operates normally, the OpenTherm device is the fault source.
Replace the service key if applicable
If a service key is connected for diagnostics and E83 persists, replace the service key as the IOM specifies that a defective key causes this fault.
Contact technical service if fault persists
If E83 continues after wiring checks and thermostat substitution, the PCB OpenTherm interface is likely damaged. Contact Utica-Dunkirk at 1-800-325-5479.
When to call a professional
Call a licensed technician if the fault persists after wiring inspection and thermostat substitution, particularly if PCB replacement is indicated. OpenTherm wiring must be polarity-insensitive but short-circuit-free — if you suspect a wiring fault inside finished walls or if PCB replacement is required, a qualified technician should perform the repair and re-commission the boiler.
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Other Utica Dunkirk Error Codes
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Sources: dunkirk.com