Water Heater / Boiler Error Codes: All Brands
Gas boiler fault codes usually indicate an ignition failure or lockout, low system pressure, overheating, or a problem with the fan or flue. The safe user checks are limited: read the pressure gauge (many residential systems run around 12–15 psi when cold), confirm that other gas appliances work, and try the reset button once. If the code returns, or you smell gas or a carbon monoxide alarm sounds, stop there and call a licensed heating technician or your gas utility – these pages contain no repair instructions for gas appliances.
ENERGY STAR certified models
| Viessmann · Water Heater / Boiler | 22 | |
|---|---|---|
| Bosch · Water Heater / Boiler | 16 | |
| Buderus · Water Heater / Boiler | 4 |
Source: ENERGY STAR open data (data.energystar.gov) – number of certified models currently listed.
Official safety recalls (US CPSC)
- Recall Program to Replace Vent Pipes on Home Heating Systems · Carbon Monoxide (CO)
- Bosch Thermotechnology Recalls Buderus Boilers Due to Carbon Monoxide Poisoning Hazard · The siphon can become blocked, leading to a delayed ignition that can damage the boiler's exhaust system, creating a carbon monoxide hazard.
- Viessmann Recalls Boilers Due to Carbon Monoxide Hazard · The boiler heat exchanger back plate can corrode and leak flue gases, allowing the boiler to emit excessive amounts of carbon monoxide, posing a CO poisoning hazard to consumers.
- Viessmann Recalls Gas Boilers Due to Fire and Carbon Monoxide Hazard (Recall Alert) · The boiler can overheat and emit flue gases into the venting system and carbon monoxide can leak throughout the residence, posing a fire and carbon monoxide hazard to consumers.
- Bosch Thermotechnology Recalls Boiler Survey Kits Due to Fire Hazard · The use of a silver-colored gas pipe adapter included in the service kit can lead to gas leakage, posing a fire or explosion hazard to consumers.
- Gas Boilers Recalled by Bosch Thermotechnology Corp. Due to Carbon Monoxide Poisoning Hazard · A problem with the boiler's ignition due to insufficient output voltage from the boiler's transformer can damage the boiler's venting. This can result in leaking flue gases, posing a risk of carbon mo
- Bosch Thermotechnology Recalls Boilers Due to Fire Hazard · An electrical connector can overheat, posing a fire hazard to consumers.
- Viessmann U.S. Recalls Boilers Due to Fire Hazard · The boiler can leak gas, posing a fire hazard to consumers.
Source: US Consumer Product Safety Commission recalls API. Check your model and serial number on the linked recall notice.