70
Noritz
Main Control Board Failure
Boiler shows error 70 and is completely inoperative.
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Internal control board fault, Power surge damage, Corroded board connectors
How to Fix / Troubleshooting
Safety: Turn OFF power at the breaker before touching any electrical components.
- 1. Power reset: Turn OFF the breaker for 1–2 minutes, then restore power to see if the error clears.
- 2. Inspect for moisture: Remove the front cover and look for signs of water leaks or condensation on the control board. If present, correct the leak source and allow the unit to dry.
- 3. Check all connectors: Gently press on all harness connectors going into the control board to ensure they are fully seated.
- 4. Surge protection: If the error occurred after a storm or outage, consider adding surge protection to the boiler circuit.
- 5. Board replacement: Persistent error 70 usually requires replacement of the Noritz control board by a qualified technician.
Advertisements
Repair Difficulty
Professional Required
5/5
Required Part
Main Control Board
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements