NTI Trinity TRX 3 P9 — Sched. Maintenance - Call for Service
3 P9
Sched. maintenance - call for service. Scheduled maintenance is due because the service reminder timer has expired; the boiler must be serviced and the maintenance timer reset using menu 8.5.2. The table classifies it as Warning.
Applies to
This maintenance or informational code is displayed by the TRX Series I control on TRX Series I models up to 150C (TRX085, TRX110C, TRX120, TRX150C), as documented in TRX 085–150C Installation and Operation Manual, doc 420010970805 Rev 01.24.23, Part 13-B Boiler Error Codes (420010970805 Rev 01). 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: 420010970805 Rev 01 (2023-01-24).
Why a code is not a diagnosis
This class of message is informational or maintenance-related: the appliance keeps running (or limits output) until the service is performed. No fault may exist beyond the interval being due.
Safe things to observe
- Book the scheduled service; the appliance will tell you when the interval is reached.
Do not
- Do not clear maintenance messages without the maintenance being performed.
How professional service helps
- A technician performs the manufacturer's scheduled maintenance and resets the counter as part of the service.
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 085–150C Installation and Operation Manual, doc 420010970805 Rev 01.24.23, Part 13-B Boiler Error Codes · 420010970805 Rev 01 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.