Normally closed vent safety circuit opened
The 137 error code on Bradford-White boilers indicates normally closed vent safety circuit opened.
Bradford-White 137 means: normally closed vent safety circuit opened. The usual causes are use a voltmeter to find out if either the pressure switch or the high limit switch has opened, if so, determine the cause (blocked vent terminal, clogged condensate drain, high temperature in compartment) or if limit switches are closed, check wiring for shorts. You can safely reset the boiler once — if 137 returns, do not keep resetting. A qualified heating engineer should diagnose the root cause.
What Does 137 Mean
The 137 code is shown by the boiler’s control board when it detects normally closed vent safety circuit opened. 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 137 and the boiler stops until the fault is cleared |
Common Causes
Causes documented in the Bradford-White service literature published by docs.bradfordwhite.com, cross-checked against the manufacturer’s fault-code table.
| Cause |
|---|
| Use a voltmeter to find out if either the pressure switch or the high limit switch has opened |
| If so, determine the cause (blocked vent terminal, clogged condensate drain, high temperature in compartment) |
| If limit switches are closed, check wiring for shorts |
| Measure continuity |
| If limit switches and wiring check O.K., replace control module |
Safety Warning
137 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.
How to Fix It
Check wiring to the normally closed blocked vent pressure switch and vent limit switch
Refer to code 67
Refer to the Bradford-White service documentation for the detailed procedure. Only a qualified engineer should carry out these repairs.
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Affected Models
Bradford-White models that can display fault code 137:
| Model Family | Output Range | Frequency |
|---|---|---|
| All Bradford-White models | — | Possible |
Frequently Asked Questions
Check wiring to the normally closed blocked vent pressure switch and vent limit switch. According to the technical documentation, this is the first check on the list for 137.
137 is not classified as a high-severity fault, so the boiler can be reset once. If 137 comes back, stop resetting: the underlying cause is still there and needs a qualified heating engineer.