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Plumbing Water Feed

Star Using PEX to get potable water and hot water to your faucets and other fixtures.


Water line to house

This is the thick walled plastic pipe (designed for direct burial in soil) that comes from the wellhouse to the house.  It needs to be a nice big diameter to achieve good water flow.  I use 2" diameter pipe.

Main water shutoff

Having a main water shutoff as it enters the house is required by code.

It is a 2" diameter underground pipe to the house which then connects to a 2" CPVC pipe inside the house.  Use a 2" shutoff tap.

Shutoff tap CPVC

Water distribution to toilets

This is done with 1.5" white CPVC pipe.

PEX for cold and hot water


For potable (ie drinking) water you need PEX tubing that DOES NOT have an oxygen barrier.  The type with an oxygen barrier is just for use in radiant heating systems where the heating system uses cast iron parts and you want to avoid rust.  If you are certain you will never have cast iron components in your heating system then you can use NON-oxygen-barrier for the radiant heating system too.  My advice is to just avoid using cast iron, ie use NON-OB PEX everywhere.

Typically use 3/4" to go to the manifold and then 1/2" to the various fixtures.

The best brand is AquaPEX.  The best type is PEX-a.  AquaPEX is the only PEX-a material available for drinking water.  Details are here .

PEX pipe blue half inchPEX pipe red half inch

Connection system

There are various connector types that can be used with PEX tubing, but here is my recommendation.  Use the crimp connectors/fittings, but use them with stainless steel clamp rings (rather than copper crimp rings).  Crimp style fittings are the most common and affordable type of PEX fittings and can be found in most home centers and online stores.   It will cost you about $70 for a clamp tool (but this is less than a crimp tool).

The clamping system is just like the crimping system but has the following advantages:

Tool fits into tighter spaces
Less accuracy is required
The tool is slightly cheaper
Less prone to operator error

PEX crimp connector - angled 

I am ok with using plastic connectors, in fact I prefer them over brass.

The best manifold uses crimp connectors (note that this also means it will work with clamp rings), so this is another reason to chose the crimp/clamp method.

Manifold - 36 PEX crimp 

Lots of extra good info on PEX is available at http://www.pexsupply.com/resources .

Little known handling characteristics of PEX

All PEX tubing not totally concealed in the wall cavity MUST BE sleeved with a UV light barrier sleeve.

PEX may not be connected directly to a water heater.

PEX tubing may not be run within 6" horizontal or 12" vertical of a water heater or furnace flue pipe, a heating unit or a fluorescent or incandescent lighting fixture.

Horizontal runs of PEX tubing must be supported at not more than 32" increments..

On a horizontal run, PEX support hangers must not restrict movement of the tubing.

On a vertical run, PEX must be supported at each floor plus halfway between floors.

When running PEX, you must allow 1" per 100 linear feet for each 10deg.F change in working temperature differential.

The minimum turning radius of PEX may not be less than 5x the tubing diameter (some local codes restrict it to 8 or 10 times the diameter).

When bending PEX tubing it may not be bent contrary to the natural curl of the tubing from the original roll.

PEX tubing must be stored and transported in a closed shipping container and should only be opened immediately before use.

PEX tubing must be cut with a plastic tubing cutter.  If a hacksaw is used, the tubing must be supported in a miter box while cutting.

All fittings used on PEX tubing must be specifically listed in the manufacturers data sheet as being acceptable for that particular brand of PEX tubing, and the manufacturers data sheet must be on the jobsite during installation.

When installing PEX tubing it may not be dragged over bare earth or a concrete surface.


Water heaters

Avoid anything that has cast iron because it will rust if you use the water for radiant heating and you use potable water PEX tubing.

Avoid a tankless water heater (unless you live alone in a one room apartment that has poor insulation and you are out all day).  A water heater with a well insulated tank will give you better efficiency and the small amount of heat that does escape will be within the thermal envelope of the house so will help warm the house.

Site the boiler where the small amount of escaping heat can be the most beneficial.  A good place is in an airing cupboard for clothes on the bedroom floor, although in practice it is more practical to put it in the basement.

Water heaters with tanks come in a full range of sizes from a few gallons (the one pictured is 6 gallons) to many 10s of gallons.

Small water heater 

Water leaks and floor drains

Safe pans are required by code under water tanks six gallons in capacity or more when elevated above any occupied space, minimum drain size is 1-1/4”.  (A safe pan or safe waste system is not required by code under washing machines.)   In my case the water heater is in the basement, ie not above an occupied living space, so a water catching pan is not required by code.

A safe pan under a piece of equipment is for emergency purposes only.  When not an emergency it will always be dry (and so a trap would be dry).  The drain from the pan must be tied indirectly (via an air gap) to an active fixture like a utility sink.

Under a water heater you do ideally want to have a mechanism for catching water if it leaks.  You don't want a floor drain in the basement slab so you need another mechanism.  I use a raised floor with waterproof membrane to form essentially a shower tray.  There is a 1.5" drain in that waterproof raised floor that goes via a 1.5" ABS pipe to above the mud-room utility sink.


Separate drinking water system

Many people will consider this to be unnecessary, but I am very fussy about my drinking water.  The main water feed to the house from the WellHouse is perfectly drinkable, but there are big holding tanks and big umps involved.  I like the water best when it is fresh out of the ground, ie has had no opportunity to get stale in a big reservoir tank.  I have chosen to implement a separate small volume water system that feeds the drinking water via a half inch PEX pipe to the house.  It feeds a dedicated faucet in the kitchen and three on the bedroom floor (in bathrooms) using a simple daisy chain.  Details of what's needed in the WellHouse to feed the PEX pipe are here .