Triangle Tube Boiler Equipment & Error Codes

Platform & Control Notes

Triangle Tube makes three distinct boiler platforms, each with its own control system and error code numbering. Prestige/Solo use the MCBA controller with E-## (hard lockout) and b-## (soft lockout) codes on a 7-segment display. The Instinct uses the CTRLMax controller with E# codes on a graphical touchscreen (different numbering from Prestige). The Keystone is a commercial condensing boiler (199-850 MBH) using a Honeywell-based controller with bare numeric codes. The Challenger combi line uses a different single-digit display. Always match the code to your specific model.

Model Families & Platforms

• Prestige & Solo (MCBA controller, E-## / b-## display)
• Instinct (CTRLMax touchscreen controller, E# codes)
• Keystone (Commercial condensing 199-850 MBH)
• Challenger (Single-digit LED combi platform)

Diagnostic Characteristics & Common Service Topics

Triangle Tube boilers utilize specific display codes and safety lockouts to protect the heat exchanger, combustion system, and hydronic loop. Everyday issues like pressure loss, flame sensing errors, or circulator faults trigger specific responses depending on the controller generation.

Sample Fault Code Summaries from Vault Records

Code	Meaning	Action Required
E-00	Flame detected before ignition — control senses a flame signal when there should be none.	Safety/gas-integrity fault — call a licensed tech. Do not run the boiler; it needs a combustion test.
E-02	Failed ignition lockout — tried to light and could not prove flame after 5 attempts.	Confirm gas is on (other gas appliances work, LP tank not empty), then press RESET once. If it relocks, stop — call a licensed tech. Do not keep resetting a gas-ignition lockout.
E-03	Gas valve harness fault — rectifier cable not connected or gas valve wiring harness problem.	Call a tech to inspect the gas valve wiring harness and rectifier cable connection.
E-04	Loss of power after a lockout — power was interrupted while already locked out, so the original code was lost.	Press RESET once on the display (not the main power switch). If E-04 keeps returning, call a tech — the underlying lockout and power quality need diagnosis.
E-05	Internal control failure — MCBA board self-test fault.	Call a tech — board likely needs replacement.
E-06	Internal control failure — MCBA board self-test fault.	Call a tech — board likely needs replacement.
E-07	Internal control failure — MCBA board self-test fault.	Call a tech — board likely needs replacement.
E-08	Internal control failure — MCBA board self-test fault.	Call a tech — board likely needs replacement.

Related Symptom & Diagnostic Guides

Sources & Documentation

• error-codes.json — Prestige Service Technician's Troubleshooting Guide; Instinct WHB Installation & Maintenance Manual; Keystone Installation & Operation Instructions
• triangle-tube-support.html — Triangle Tube North American operations shutdown note (Nov 3, 2025)