am doing a full replumb on a crawl space house I purchased from foreclosure. 1in goes from the well head to the pump. The pump is a 30/50 psi switch (Can I upgrade to a 40/60 ?????) The pump has 1in in and out. 1700sf house on a crawl space. Will the pipe size have any negative effect on the hot water??? For cold does it matter? Someone said I should use smaller diameter pipe on the hot??????


The hot water heater is roughly 20 ft from the cold water entering the crawl space.

HOT 24 feet till the hot hits the first fixture (shower) then a daisy chain to the sink (6 feet) then another shower (4 feet) then another sink (6 feet) somewhere in the 24 foot run there is a 12 foot run to the sink in the kitchen and a 6 foot run to laundry area.

COLD 56 feet for 2 faucets
74 feet for 2 other faucets
the rest of the cold is identicle to the hot besides it hits 2 toilets in between the showers. There is an ice/fridge that could use water hook ups as well but right now it is hooked up to the sink.

Remember that 3/4" CPVC is approx. equal to 1/2" copper.
A case can be made for hot to be in smaller pipe, such as the 3/4 cpvc. Since showers and sinks demand relatively small volume anyway, having a smaller volume in the pipe will get hot water to you faster, with less water waste.
If you plan to fill a tub, then large pipes would be called for. Anything like a kitchen sink or washing machine also would be affected by small cold pipes/

quote; Can I upgrade to a 40/60 ?????)

Usually all you have to do is raise the cut-off point, the differential will stay the same. If the piping is undersized, it will affect the water flow regardless of whether it is hot or cold water. They recommend the smaller size for hot water so there is less "cooled" water to evacuate before the hot water arrives, but that would be a secondary consideration to whether the pipes are too small to deliver adequate volume and pressure. Using CPVC, or any plastic, creates a problem since the pipes are effectively one size smaller than the same "size" copper tubing, due to the increased wall thickness.



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Where pressure is lower !!!the next higher sized tubing is the least expensive procedure.30 50 from the service.if you can post 1" to the heater.do so.I would not allow a service less than 40 60.Sorry if you must use the provided.

The way to upgrade from a 30-50 to a 40-60 is remove the cover from the pressure switch and tighten the nut to compress the spring. You will also need to drain the pressure tank and add about 10 psi of air to it.

If pressure is low, you can use 4" water lines and it will STILL be low.

you need a code book from your state and teach yourself to size water pipe...or id recommend hiring a plumber as an adviser to make sure you get it right....for a couple of hundred id draw you a plan with sizes.....

if its incorrect and you dont get permits you can be sued by the new owners...

most likely id do 1" from the meter to where it splits off to the water heater and do 3/4 hot and cold from there...but like i said you need to learn how to size it yourself on site

3/4 cpvc is more like a 5/8(not a 1/2)

quote; 3/4 cpvc is more like a 5/8(not a 1/2)

We SELDOM use 5/8 tubing, (it is an air conditioning size), in plumbing systems, and since there is a big difference between 3/4" and 1/2", CPVC is closer to 1/2" copper than it is 3/4".

Hj.working backward to arrive at the needed flow rates to serve a home by code is less than what is done.!.6 gallon max flow at a fixture and working backwards may find the code less than the idea working system.Most fixtures are feed with 3/8"or less id tubing.In the case of hot tubing less may very well work better.Where in the old days fixtures where located near the source and close together. Today's spread plans, leaves sizing to the pros.the system pressure has and always will set the tubing use .I expect to see much more use of smaller id thicker walled even self insulated tubing, higher pressure home supply systems.something like pre foam covered sch 80 cpvc.