6600-017, Sundance 850 Circuit Board 1995-1996:1&2 Pump Systems with PermaClear.

Permaclear is a Circulation Pump that would be hooked up to the inlet side of the heater. Small pump is gray, red or black.(Eprom Rev. 1.28FB included).Must use this Eprom that comes with board when replacing board.

Sundance Spas used the 6600-017 and 6600-018 as the same board many times and would replace the eprom to the system.To help clarify: Circulation Pump Systems have used Eproms with 1.28E, 1.28F and 1.28FB. So if your board has on of these Eprom chips (usually starts with REV and located on a chip on the board), then you have a system with a circulation pump and this is your board: 6600-017. A Non Circulation Pump System used an Eprom chip with a 1.29 number, so if your board has an Eprom chip with a 1.29 (usually starts with REV and located on a chip on the board) then the circuit board you need is this one: 6600-018

Also note that a circulation pump is not one of the main spa pumps but is a small pump like a Grundfos or Laing Pump:

http://www.sundanceparts.com/6000-125-Sundance-Spas-Circulation-Pump-p/6000-125.htm

Technical Note: 6600-023, 6600-028, 6600-017, 6600-018 are the same circuit boards with different eproms.