To fix a bogus heater limit error I finally replaced the Main PC board (Caldera #77089) on my 2004 Caldera Paradise Martinique, after having exhausted all other avenues--including replacing the heater unit.
Finally, no more heater limit shutting down the heater (yay!).
However, while Pump 1 can be started and run, Pump 2 does not start when the button on the Display panel is pressed. Pump 2 did work fine before replacing the board, and connecting the Pump 2 wires to the Pump 1 board tabs as a test proved that Pump 2 does still work.
(There is a note associated with the 77089 board that "On 2002 and 2003 Models we reccomend [sic] you also replace Top Side Control on some models the old topside will not be compatible with the new board." The Martinique was introduced in 2004, so that should not apply to this.)
Per the document that came with the 77089, jumpers JP1 and JP9 were set.
Voltages were checked on the Pump tabs, showing 245V on Pump 1 (BLK->WHT) while it was operating with 116V going to ground on both the Pump 1 and Pump 2 BLK->GRN tabs.
Checking the Pump 2 tab voltage never budged from Zero when pressing the Pump 2 button--not even for a moment.
I've repeatedly tried to contact the company that sold me the board, and Caldera, and have gotten no response.
So now I'm trying to determine whether I've got a (slightly) bad board, since all its other functions seem to be fine; or if there's another jumper somewhere that needs to be set; of if there's some other connection or whatever that needs to be done. The 77089 board is sold as a replacement for "all 2002-2008 Caldera Utopia and paradise Models," but it is not identical to the board it replaces. Other than a different JPx jumper setting though (where I followed the board's docs), everything on the old board corresponded to the new.
Thanks for any advice or assistance, and please correct me if I appear to be misunderstanding anything. Plus I'll be happy to follow any diagnostics advice.