Record what changed
Give the technician the model, original setting if known, new setting, and who performed the adjustment. Explain whether only an external owner control was used or covers were removed.
Save any existing photograph or display message. Do not remove covers again to document internal settings.
Note whether the heater now provides no hot water, some warm water, or hot water at only certain fixtures. Include any breaker trip or internal reset.
Verify the model's adjustment requirements
A. O. Smith's residential electric temperature bulletin requires electrical supply off before adjustment under its procedure. That guidance does not authorize work on unfamiliar internal controls. A. O. Smith temperature-control guidance.
Ask the qualified provider to compare the adjustment with the exact heater's owner and service instructions. Different models may have different controls, sensors, or thermostat arrangements.
Do not copy a reset sequence or wiring layout from another heater. Do not turn settings up repeatedly to try to recover heat.
Request the actual finding
Have qualified personnel assess electrical supply, controls, relevant protective devices, and heating components as the model requires. Ask whether the setting, an affected connection, an existing fault, or something else explains the failure.
A tripped limit needs a reason, not only a reset. A part recommendation needs a supported failure finding.
Verify the correction
Request the approved operating setting, any necessary repair, and a check of delivered hot water afterward. Ask how the provider will protect against unintended high temperatures.
Your next step is to contact a qualified water-heater provider with the adjustment history. Leave further internal work to them and request a documented cause and verified return to operation.