Quote Originally Posted by nefretrameses View Post
My pool had three 1-1/2 inch lines on the suction side of the pump all teed together to the 1-1/2 inch pump fitting. Then 1-1/2 to the filter and back to the pool. At the pool there's an in-floor cleaner valve to four circuits. I had the opportunity to change to 2 inch from the pump discharge to the in-floor valve - about 60 feet total. My discharge pressure dropped by about 1/3. Your fittings will cause some loss, but the 2 inch pipe is really gonna be the biggest factor. You can use two 45 degree fittings instead of 90's and save a bit more.

Not sure about your combo valves or adhesive. There should be a way to adapt PVC to CPVC, but its not in my bag of tricks to know how. If your heater wants a 6 inch nipple, its probably for "straightening out" the water stream before it gets inside. Not sure how much you want to compromise that, but again, its not really in my bag of tricks. Sorry.
Yeah, I am more worried about the 1.5"/2" combo fittings/valves being a restriction point more than anything else...

In regards to the 6 inch nipple, the only reason they have that is so that if there is a thermal control problem with the heater you don't melt connected PVC pipe (since CPVC has a much higher rated temperature). The issue has more to do with the potential heat of the manifold compared to the water, ie, if there is a thermal problem the water can be cooler but the manifold can get much hotter. By the time the thermal overload switches disable the heater the manifold can be much to hot for PVC to handle, so with CPVC and a length of 6" they are just anticipating that it would hopefully save the PVC up/downstream from the heater. The big concern outside of a thermal issue is if you don't put a firemans switch in and just shut down the pump/heater and water boils inside the heater. A much more common occurrence and 6" of CPVC is hopefully enough to protect any PVC downstream/upstream from the heater.

I figure a short nipple with an immediate 90 and another nipple being threaded into a PVC female should afford for at least 6-8" of total CPVC distance. That coupled with my installing a firemans switch will make sure I don't run into that situation. The only time it *might* happen is if we lose power while the heater is running. At that point there isn't much I can do, so the CPVC should hopefully do it's job.