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Lochinvar Water Heater Troubleshooting
bytechtown
Water heater malfunctions come in a wide variety of problems, from displays not working to the burner malfunctioning. If you need help learning Lochinvar water heater troubleshooting, follow along with our guide below. We’ll help you get the water heater operational and ready for heating in no time.
How Do I Troubleshoot a Lochinvar Water Heater?
| Problem | Cause | Solution |
| No display | No voltage supplied to unit Display board faulty Main control board malfunctioning Fuse is blown | Check external line switch, fuse and breaker Check wire harness connection between display board and main control board Replace faulty display board Replace main control board Replace fuse F3 on main control board |
| Burner not operating | Tank temperature set point satisfied Unit locked out on fault | Check temperature setting Check display for specific fault |
| Unit doesn’t modulate over 50% | Open flue sensor | Verify flue sensor is located in flue outlet Check wiring connections at flue sensor Confirm flue sensor resistance is accurate |
| Noisy operation | Gas supply issue Gas/air mixture problem Dirty or damaged burner Low water flow through the heat exchanger Air in piping system | Check gas pressure is at correct levels Verify that vent/air intake lengths don’t exceed maximum Clean or replace burner as needed Verify pump operation Purge air from piping system |
| No pump operation | Fuse blown Faulty pump Faulty pump relay Internal malfunction on control board | Replace fuse F5 on control board Replace pump Replace pump relay Replace main control board |
| Relief valve opening | System pressure exceeds relief valve setting | Lower system pressure below 150 PSI rating of supplied relief valve |