HTP UFT Combi Er:16 — Operating Temperature Sensor Detects Water Temperature Greater Than 203°f (95°c)
Er:16
Operating temperature sensor detects water temperature greater than 203°F (95°C). This Error Code will go away when the DHW temperature decreases. If Error happens again: 1. Check if dip switch High Fire setting is ON. Switches 6 and 7 should be OFF for normal operation. 2. Check if DHW inlet pipe is blocked. Ensure there is enough water flowing to the boiler. 3. Check DHW sensor at DHW outlet. If resistance is zero, replace the sensor. 4. Check Operating Temperature sensor at the heat exchanger. If resistance is zero, replace the sensor. 5. If the problem persists, replace the main control. NOTE: During the error state, the pump will operate to cool the boiler until the temperature is below 192oF. The table classifies it as Error (Soft/Hard Lockout).
Applies to
This venting or air-supply fault code is displayed by the UFTC control (Er:## codes) on UFT Combi models (UFTC-140/199 wall and floor), as documented in UFT Combi Installation Manual, LP-648 Rev. 001 Rel. 004 (4.15.20; boilers manufactured before 1/1/2020), Table 30 (LP-648 Rev. 001 Rel. 004). Codes can differ between controller generations, so always check the manual that matches your unit.
Controller: UFTC control (Er:## codes). Source manual: LP-648 Rev. 001 Rel. 004 (2020-04-15).
Why a code is not a diagnosis
A venting or air-supply code points at the combustion-air path: a blocked terminal, a restricted flue, a failed fan, or a condensate restriction. It does not say which, and running an appliance with a blocked flue is unsafe.
Safe things to observe
- If a carbon-monoxide alarm sounds anywhere in the building, leave immediately and call 911 from outside.
- From a safe distance, check that the vent terminal and combustion-air inlet are not blocked.
- Do not run the appliance while a blockage is suspected.
Do not
- Do not put anything into the vent or air-intake openings.
- Do not remove or modify vent pipe.
How professional service helps
- A technician inspects the full vent and combustion-air path, clears blockages and checks the fan.
- 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.
Parts and service
Parts commonly involved
These parts appear in the documented text for this alert. A code reports a condition, not a failed part — a technician confirms the cause by testing before anything is replaced.
Heat exchanger
The heat exchanger is where a boiler transfers heat from the burner flame to the water that heats your home.
What a technician checks →Boiler sensors (thermistors)
Boiler sensors are small temperature probes, usually thermistors, that tell the control how hot the water and flue gases are so it can fire safely…
What a technician checks →
Service for this alert
- Gas Boiler Repair
Licensed gas technicians from ROMA Heating & Cooling diagnose and repair residential and light-commercial gas boilers across…
- Emergency Boiler Repair
Priority gas boiler repair for homes and buildings in Greater Vancouver with no heat, no hot water, a locked-out boiler or a leak.
- Gas Boiler Replacement
ROMA replaces old, failed or inefficient gas boilers in Greater Vancouver, handling removal, venting and gas-supply changes,…
Every boiler part explained — what it does, how it fails and what a technician checks.
Documented for HTP UFT Combi (discontinued).
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
- UFT Combi Installation Manual, LP-648 Rev. 001 Rel. 004 (4.15.20; boilers manufactured before 1/1/2020), Table 30 · LP-648 Rev. 001 Rel. 004 · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.