NTI Trinity TRX EMERG — Cascade Boiler Lost Communication - Boiler Operates in Emergency CH Mode
EMERG
Cascade boiler lost communication - boiler operates in emergency CH mode. The cascade boiler lost communication and operates in CH mode with the emergency setpoint temperature; causes include EBUS wiring problems, incorrect address settings, the master boiler being turned off, or incorrect bus wiring.
Applies to
This communication or network fault code is displayed by the TRX Series I control on TRX Series I models from 150 up to 199C (TRX150, TRX199, TRX199C), as documented in TRX 150–199C Installation and Operation Manual, doc 420011303700 Rev 2024.02.16, Part 13-B Boiler Error Codes (420011303700). Codes can differ between controller generations, so always check the manual that matches your unit.
- NTI Boilers Trinity TRX
- NTI Trinity TRX085
- NTI Trinity TRX120
- NTI Trinity TRX150
- NTI Trinity TRX199
- NTI Trinity TRX110C
- NTI Trinity TRX150C
- NTI Trinity TRX199C
Controller: TRX Series I control. Source manual: 420011303700 (2024-02-16).
Why a code is not a diagnosis
A communication code involves the link between controls (cascade, remote, sensors on a bus). Another unit being off, a wiring fault or an address conflict can all produce it.
Safe things to observe
- Check that every appliance in a multi-unit plant has power.
- Report the code together with any other codes on the system.
Do not
- Do not re-address or rewire control networks yourself.
How professional service helps
- A technician verifies power, wiring and settings across the connected units.
- Combustion and safety devices are verified with an analyser and the manufacturer's procedure after any repair.
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Frequently asked questions
Can I clear this code myself?
Clearing a code without fixing its cause usually just brings it back. Note the code, check the safe items on this page, then call a licensed technician. If your appliance manual describes a user reset for this exact code and it stays away, no call may be needed.
Boiler locked out? Call with the alert text ready.
The brand, model and this alert are passed along when you request service online, so the technician arrives prepared.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
- TRX 150–199C Installation and Operation Manual, doc 420011303700 Rev 2024.02.16, Part 13-B Boiler Error Codes · 420011303700 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.