We bought a house with a Master Spas Insider Series spa. It has Balboa controls but done OEM for MasterSpas - the front cover of the box says DEM-MAS560-DCAH, there is also the number X30074 on it.

There is a box with a 50 amp breaker, so I presume this is not a 110 set up.

We filled the tub, turned it on. It heated up, things were working. At some point the control panel had all LED lit (temp/time area read 8888, etc.) none of the panel buttons would work. If I turned it off at the box and back on, it would prime for 4 minutes, things would work, and eventually the same results.

We had someone look at it. He replaced the sensors. We refilled the tub (bled the pump!) and have had similar results. This morning it is showing a nuance. After being on for 3 hours and going through its pre-set filter cycle and maintaining heat, now the panel buttons are dead, and only the right side of the display shows anything. The time/temp side is blank. I can see the words for the 3 modes: STANDARD, ECONOMY, SLEEP and icons for the spa light and the thermometer for the heater.

Any suggestions on what to test or try out would be welcomed.

THank you -- GJ

Based on the information at hand, I would suspect a defective topside control panel.