System type: Pumped – differential control
The anti-scald valve was stuck and could not be turned to another position. Appears that the owner had attempted to adjust valve setting unsuccessfully.
When I manually set the controller to Off, the LEDs starting blinking uncontrollably – and a clicking noise was heard. Flicking the switch several times eliminated this occurence.
At least ½ of the exterior pipe insulation had degraded to a point where there was no insulation and the copper piping was exposed. The sensor lead- sensor wire connection was not well protected. The sensor wire flashing was no longer sealed to prevent water penetration.