NTI Trinity Lx 224 — DHW Frost Protection Temperature Was Invalid
224
DHW frost protection temperature was invalid. The control flagged the DHW frost protection temperature as invalid, and this alert reports the invalid value that was detected. The table classifies it as Alert.
Applies to
This domestic hot water fault code is displayed by the Trinity Lx control on Trinity Lx models (Lx150 through Lx800), as documented in Trinity Lx 150–800 Installation and Operation Manual, doc 99986573 V.2024-06-28, Tables 17-3 and 17-4 (99986573). Codes can differ between controller generations, so always check the manual that matches your unit.
- NTI Boilers Trinity Lx
- NTI Trinity Lx150
- NTI Trinity Lx200
- NTI Trinity Lx300
- NTI Trinity Lx400
- NTI Trinity Lx500
- NTI Trinity Lx600
- NTI Trinity Lx700
- NTI Trinity Lx800
Controller: Trinity Lx control. Source manual: 99986573 (2024-06-28).
Why a code is not a diagnosis
A DHW code involves the hot-water side: sensors, flow, the mixing/bypass valve or the DHW heat exchanger. It does not say whether the fix is a sensor, a valve or a flush.
Safe things to observe
- Note the code and whether the problem follows a hot-water draw or appears at all times.
Do not
- Do not open the appliance to test DHW components yourself.
How professional service helps
- A technician tests the DHW sensors, flow switch and valve circuits, and cleans the DHW path where the manual directs.
- 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
- Trinity Lx 150–800 Installation and Operation Manual, doc 99986573 V.2024-06-28, Tables 17-3 and 17-4 · 99986573 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.