Gtlegend

I have a customer with a spa quip sp601 controller, which has been replaced as error 6 suggested that it may be the controller. It still does not pump water ( start up noises can be heard when the digital panel is re started ). The element measures ok, the wiring is correct. The blower is working but does not restart. The pipes have been ain bled. Any one have any ideas as to the continuing problem? Thanks in advance.