Search
Contact
Where to buy
My Bosch
Terms of Use
Startpage Bosch USA
Helpful Resources
Technical Support
Bosch AquaStar Models
2400ES Tech Support
Troubleshooting
Welcome
Startpage Bosch Hot Water
Consumer Information
Gas Products
Electric Products
Point-of-Use Products
Online Warranty/Registration
Find a Service Agent/Installer
Helpful Resources
Technical Support
Bosch AquaStar Models
PowerStar Models
Ariston Models
Powerstream Models
Ecotherm Models
Purchase Reconditioned Units
Purchase Parts
Product Selector
FAQs
Brochures & Manuals
Search
Retailer Listings
Where to Buy
2400ES Tech Support
Problem Solving Error Codes
Q.
A2: Fault in the flue gas limiter
Q.
A3: Jumper connection is not correct.
Q.
A4: Backflow temperature sensor defect - happens if sensor is disconnected or short circuit.
Q.
A7: Outlet temperature sensor fault (Temperature below freezing or above 210ºF).
Q.
A9 (flashing): Outlet temperature sensor not sensing expected output temperature.
Q.
C6: Primary fan rotation too low on operation.
Q.
C7: No rotational speed sensor signal from primary fan.
Q.
CA (flashing): Water flow signal over specified maximum value. Water flow > 10 gallon/min.
Q.
E0: Internal hardware/software failure.
Q.
E1: Over-temperature detected by outlet temperature sensor on hot water pipe. Temperature > 185°F
Q.
E2: Cold water temperature sensor fault.
Q.
E4: Backflow temperature sensor over 309°F. The appliance will close the burner and lock.
Q.
E9: Overheat sensor (ECO) open circuit (should reset when cooler temperatures are detected).
Q.
EA: No flame ionization detected with water flow.
Q.
EC: Ionization failure during operation.
Q.
F7: Ionization error at standby.
Q.
FA: Gas leakage error, gas valve circuit not closing properly.
2400ES Tech Support
Troubleshooting
Installation Manuals
Accessories
Interior Parts Diagram
Service Bulletins
Bosch Tech Support Form
Note: Specifications and product information subject to change without notice.