We just got a new to us Hydropool H738 7 person hot tub. While most of the time it runs fantastic, we are getting the FL error message, which shuts off the jets, then resets itself after 5 minutes or so. I've looked it up and this seems to be a pressure switch issue. Is it easy/inexpensive to replace? Is this something that can be done ourselves or do we need to hire a professional. We have already put a ton of money into updating our deck, having an electrician hard wire, etc., and really don't have much left to spend! Thanks for any advice!