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NTI Boilers · Error codes

NTI Trinity FTVN 2 05 — DHW in Probe Open Circuit

2 05

Needs attentionNTI Trinity FTVN Series II boilers and combis (Series II control, I&O 420012001400)

DHW In probe open circuit. The DHW inlet probe circuit is open; the manual lists no specific cause and instructs performing a factory reset using menu 2.8.0. The table classifies it as Blocking (Auto Reset).

Applies to

This sensor fault code is displayed by the FTVN Series II control on FTVN Series II models (FTVN085, FTVN110, FTVN150, FTVN199 and combis FTVN110C, FTVN150C, FTVN199C), as documented in FTVN Series II Installation Startup Maintenance Instructions, doc 420012001400 Rev 10, Part 13-B Boiler Error Codes (420012001400 Rev 10). Codes can differ between controller generations, so always check the manual that matches your unit.

Controller: FTVN Series II control. Source manual: 420012001400 Rev 10 (2024-06-15).

Why a code is not a diagnosis

A sensor code usually means the sensor, its wiring or its mounting is faulty; the physical condition the sensor measures (temperature, pressure, flow) may be perfectly normal.

Safe things to observe

  • Note the code; there is no homeowner-accessible check for sensor circuits.
  • If the appliance still runs, watch whether the code returns and report it when you call.

Do not

  • Do not open the appliance to test or replace sensors yourself.

How professional service helps

  1. A technician measures the sensor and harness against the manual's values and replaces the faulty component.
  2. 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.

See all service areas

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

Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.

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