This is the 20'x40' 26,000 gallon IG pool we have, with some notes on where the plumbing comes into the side of the pool. I'm considering starting nearly from scratch, doing some re-plumbing and replacing ALL the mechanical & electrical to the shed where everything in hidden behind. Thankfully everything seems fine thus far with the pool & liner (knock on wood), but the electrical isn't to code so that's being upgraded first with a new service & proper grounding.
I spent last summer behind the shed trying to repair a pump that blew 3 motors, wasting a boatload of time and money - and never got an answer as to why this happened*. Me and my wife are dropping some serious $$$ on home repairs (furnace, AC, water heater, new electrical service to the pool shed), so we're just going to add to that loan and replace everything mechanical back there: new plumbing at the pad, new pump, new filter, and our first heater. We have an old Pac-Fab TR-60 that I rebuilt last summer, which may still be good, but at the very least, we'll be putting a new multipart valve on the old TR-60. I'm pretty much open to whatever gear goes back here, so long as it all works!
I've discovered that there's a leak in the (30 year old) black flex pipe to the skimmer, and if I am (or someone else is) going to have to dig that pipe up, I'm considering putting in 2" or 2.5" suction lines back to the shed. We might as well up the size on the deep end vacuum line while we have the trench from the skimmer to the shed dug up, right? The way the pipes run would probably mean the 1.5" return line would stay put (it's also tested to be working fine). Also, the skimmer we have only has 1.5" pipe connections, so if we up the size of the pipe, should we consider replacing the skimmer as well? If we did, I'd like to do so with a deeper throat skimmer, so we can put some pavers around that side of the pool.
As I noted above, I'm open to any suggestions at this point, if we're going to be re-plumbing the pipes to a bigger size. I'm not 100% sure I'm on board with the quotes I've gotten thus far (both want to install some massive pumps and leave them running 24/7), so I wanted to see if anyone had some thoughts on what they do in this situation, such as what would be the starting point for designing their system?
*: We suspect what was blowing the motors last year was a combo of electrical issues and the suction side leak. We upgraded our house electrical panel, as it was NOT tripping breakers, even on a major fault which melted a receptacle. As such, the old motors were pulling WAY more current than otherwise would have been allowed by the new panel we have now. I'm also suspecting that the pump was having to work much harder with at least one leak in the skimmer pipe, which may have made it run hotter? Either way, new electrical and new plumbing should rule out either of these problems moving forward...
EDIT/UPDATE 1 (5/24/2016): we are now moving forward with a new heater, new Superflo VS pump, new hi-flow multi-port valve (for our existing sand filter), a new liner, and new plumbing runs of 2" poly pipe.