Internal hardware error
The Refhi Too Lo Error error code on Utica boilers indicates internal hardware error.
Utica Refhi Too Lo Error means: internal hardware error. The usual cause is wrongly programmed bcu or pb. You can safely reset the boiler once — if Refhi Too Lo Error returns, do not keep resetting. A qualified heating engineer should diagnose the root cause.
What Does Refhi Too Lo Error Mean
The Refhi Too Lo Error code is shown by the boiler’s control board when it detects internal hardware error. The boiler then stops instead of continuing to run in that condition: the code is the appliance reporting a problem, not proof that the boiler is broken.
| What you see on the boiler |
|---|
| The display shows Refhi Too Lo Error and the boiler stops until the fault is cleared |
Common Causes
Causes documented in the Utica service literature published by uticaboilers.com, cross-checked against the manufacturer’s fault-code table.
| Cause |
|---|
| wrongly programmed BCU or PB |
Safety Warning
Refhi Too Lo Error involves electrical or pressure-related components. Do not attempt repairs without proper qualifications. Ensure the boiler is electrically isolated before any inspection. If you notice water leaks, unusual sounds, or pressure anomalies, contact a qualified heating engineer immediately.
Parts & Prices
Prices shown are indicative. Actual prices and availability vary by region.
Step-by-Step Diagnosis
Consult service manual
Refer to the Utica service documentation for the specific diagnosis procedure for fault code Refhi Too Lo Error.
Check error log
Access the boiler error log to check for related fault codes that may help identify the root cause.
Contact manufacturer support
If the fault persists after basic checks, contact Utica technical support for specialist guidance.
How to Fix It
Have this checked: wrongly programmed BCU or PB
Refer to the Utica service documentation for the detailed procedure. Only a qualified engineer should carry out these repairs.
Diagnostic Tools
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Affected Models
Utica models that can display fault code Refhi Too Lo Error:
| Model Family | Output Range | Frequency |
|---|---|---|
| All Utica models | — | Possible |
Frequently Asked Questions
Refhi Too Lo Error is not classified as a high-severity fault, so the boiler can be reset once. If Refhi Too Lo Error comes back, stop resetting: the underlying cause is still there and needs a qualified heating engineer.