Weil-McLain A162 Error — What It Means
The A162 code does not appear in current Weil-McLain AquaBalance or Ultra service manuals. It may be a model-specific display code, a transcription error, or an internal history code shown through a diagnostic menu rather than a standard active lockout. Weil-McLain error codes are not universal across their product lineup and vary by control family (AquaBalance, Ultra, CGa, EG, Evergreen, or other series).
To identify the exact meaning, causes, and repair steps, you need your boiler’s full model name and control display photo. Weil-McLain manuals are written for qualified heating installer and service technicians. If the boiler is in lockout or displaying an unfamiliar code, consult your model-specific manual or contact a licensed contractor with the control panel (CP) number, model, size, install date, and a photo of the display.
Common Causes
- Code transcription or display error (~30%) The number may have been misread or the display may be showing a sequence of codes rather than a single fault.
- Internal diagnostic or history code (~25%) Some Weil-McLain controls store past events in a history menu that cycles through numbers not listed in the standard fault table.
- Model-specific or legacy code (~20%) Older or niche Weil-McLain series may use codes not documented in current AquaBalance or Ultra literature.
- Control board firmware variant (~15%) Different firmware revisions or third-party control retrofits can introduce codes outside the factory manual.
- Wiring or connector issue causing garbled display (~10%) A loose connector or voltage glitch can produce non-standard characters or numbers on the control screen.
Quick Diagnosis
Answer these to narrow it down fast.
Does the display show any other text or symbols alongside A162?
No: The code may be an internal or history entry; consult your model manual or a qualified technician.
Is the boiler currently locked out (no call for heat, burner will not fire)?
No: The code may be a historical event; check the manual's history-code section or call a tech to interpret.
Can you find a fault-code table in your boiler manual or on the control door label?
No: Locate your model number, download the manual from Weil-McLain's website, or call a licensed contractor for code lookup.
Step-by-Step Fix
- Record the full boiler model number from the rating plate (usually on the front jacket or inside the burner door).
- Photograph the control display showing the A162 code and any other indicators or text.
- Locate your boiler’s service manual (mounted inside the jacket, available online, or from your installer) and turn to the fault-code table.
- Compare A162 to the table; if it does not appear, check for a diagnostic or history menu section that explains non-standard codes.
- Contact Weil-McLain technical support or a licensed heating contractor with the CP number, model, size, install date, and display photo to obtain the code’s exact meaning.
- Do not reset the boiler repeatedly if it is in lockout; repeated resets can mask the true fault and damage components.
- Follow the manufacturer-grounded repair procedure once the code is identified, using only qualified technicians for gas, electrical, or control work.
Parts Often Needed
| Part | Notes |
|---|---|
| Control board (model-specific) | Amazon | Only after confirming the code meaning and fault with a technician; CP number required for exact match. |
| Temperature or pressure sensor (model-specific) | Amazon | Common faults once the code is decoded; consult the manual’s sensor specifications. |
When to Call a Pro
Call a licensed heating contractor immediately if the boiler is locked out, will not fire, or displays an unfamiliar code. Weil-McLain service manuals are written for qualified installer and service technicians, and troubleshooting gas-fired boilers requires knowledge of combustion, venting, gas piping, and high-voltage controls. For warranty claims, your contractor will need the CP number, model, size, install date, failure reason, failed part description and number, and photos. Do not attempt to replace control boards, sensors, or gas valves without professional guidance, because mismatched parts or incorrect wiring can create safety hazards and void the warranty.
Rough cost: A pro service call runs about $150-350 for diagnostic and typical control or sensor repair.