Weil-McLain Boiler A141 Error — What It Means
The A141 code does not appear in widely available Weil-McLain fault-code tables or manufacturer FAQs. Weil-McLain publishes different fault codes for different product lines (Ultra, EcoNet, GV90+, etc.), and many codes are model-specific. Without your exact model number and manual, it is impossible to say whether A141 refers to a sensor fault, a limit lockout, a communication error, or something else entirely.
The correct first step is to enter your boiler’s diagnostics or fault-history menu (the procedure is in your model’s installation and service manual) and read the stored lockout or alarm text. That screen often gives a plain-English description or a longer fault number that points you to the right section of the manual. Do not buy parts based on the display code alone, because the same three- or four-character code can mean different things on different models.
Before You Replace Anything
Homeowners sometimes replace a control board or sensor after reading a code online for a different Weil-McLain model. Always match the fault code to your exact model’s manual and check the fault-history log before ordering parts.
Common Causes
- Model-specific sensor fault (~30%) Many Weil-McLain boilers use A-series codes for temperature or pressure sensor faults, but the exact sensor varies by model.
- High-limit or rollout lockout (~25%) Some models map A-codes to safety-limit trips that require manual reset and inspection of venting and combustion-air flow.
- Communication error between control and display (~20%) On boilers with separate display modules, A-codes can indicate a wiring or data fault between the boards.
- Ignition or flame-proving fault (~15%) Certain models reserve A-codes for ignition lockouts, flame-sensor contamination, or gas-valve faults.
- Low water or pressure fault (~10%) A few product lines use A-codes to flag low system pressure or a faulty low-water cutoff.
Quick Diagnosis
Answer these to narrow it down fast.
Does your boiler's display show a plain-English fault description alongside A141?
No: Enter the diagnostics menu (usually by pressing and holding a button combination listed in the manual) to read the full fault log.
Does the fault clear after a power cycle and stay off for at least one heating call?
No: The fault is active and repeatable. Write down the exact model, the fault history text, and call a qualified heating technician to diagnose the underlying cause.
Can you find your model's installation and service manual (often available as a PDF on Weil-McLain's website or inside the boiler jacket)?
No: Contact Weil-McLain technical support with your model and serial number. They can send the correct manual and explain what A141 means for your unit.
Step-by-Step Fix
- Record the exact model and serial number from the rating plate on the boiler jacket.
- Enter the diagnostics menu using the button sequence in your model’s manual (often a long press of two buttons together).
- Read the fault-history screen and write down the full fault description, date, and time stamp for each stored event.
- Look up the fault code in the service manual’s fault table. If A141 does not appear, check whether the manual lists only three-digit codes or uses a different numbering system.
- Perform the diagnostic checks listed in the manual for that fault (for example, measure sensor resistance, verify system pressure, or inspect the flame sensor).
- Clear the fault if the manual instructs a reset, then monitor the boiler through one or two heating cycles to see if the fault returns.
- Call a licensed heating technician if the fault recurs, if you cannot find the code in your manual, or if the diagnostic steps point to a gas-valve, control-board, or venting problem.
Parts Often Needed
| Part | Notes |
|---|---|
| Temperature sensor (model-specific) | Amazon | Order by the part number in your model’s illustrated parts list, not by the fault code alone. |
| Flame sensor | Amazon | Only if the fault-history text or manual diagnostic tree points to a flame-proving fault. |
When to Call a Pro
Call a licensed heating contractor immediately if the boiler will not fire, if you smell gas, or if the fault involves a high-limit lockout (which can signal a venting or combustion-air problem). Also call a pro if you cannot find your model’s manual, if the diagnostics menu shows a fault you do not understand, or if the recommended test requires measuring gas pressure, checking flame current, or working inside the sealed-combustion chamber. Boiler controls involve line voltage and natural gas or propane. Misdiagnosis can waste money on the wrong part and leave a real safety hazard in place.
Rough cost: A pro service call runs about $200–500.