The Poop Scoop Plumbing facts, helpful tips, DIY, and more!

15Oct/110

Repiping with PEX

What is PEX piping?

PEX piping is an innovative new product for hot- and cold-water plumbing systems. PEX is the abbreviation for cross-linked polyethylene (PE-X). It's the result of a production process in which links are formed between polyethylene molecules (thus the name "cross-linked"), forming a network of connected molecules. The result is a material that is highly durable and can withstand high temperatures.

Read more: About PEX Piping | eHow.com http://www.ehow.com/about_4728209_pex-piping.html#ixzz1atsbf2U5



What is PEX used for?

PEX tubing is widely used to replace copper in plumbing applications. One estimate is that residential use of PEX for delivering drinking water to home faucets has increased by 40% annually, and there is substantial evidence that PEX is or will soon become the dominant technology for carrying water in homes and businesses in the next decade or so. It is widely accepted among different groups, and has been used by volunteer organizations such as Habitat for Humanity in constructing homes. In 2006, the Philadelphia Inquirer recommended that plumbing installers switch from copper pipes to PEX.  In the twentieth century, the first plumbing pipes were made from galvanized steel water pipes, but users experienced problems with the internal build-up of rust which reduced water volume, but these were replaced by copper pipes in the late 1960s. Plastic pipes with fittings using glue were used as well in later decades. Initially PEX tubing was the most popular way to transport water in hydronic radiant heating systems, and it was used first in hydronic systems from the 1960s onwards. Hydronic systems circulate water from a boiler or heater to places in the house needing heat, such as baseboard heaters or radiators. PEX is suitable for recirculating hot water. Gradually PEX became more accepted for more indoor plumbing uses, such as carrying pressurized water to fixtures throughout the house. Increasingly, in the 2000s, copper pipes as well as plastic PVC pipes are being replaced with PEX. PEX can be used for underground purposes, although one report suggested that appropriate "sleeves" be used for such applications.

What are the benefits of PEX?

  • Flexibility. PEX has become a contender for use in residential water plumbing because of its flexibility. It can bend into a wide-radius turn if space permits, or accommodate turns by using elbow joints. In addition, it can handle short-radius turns, sometimes supported with a metal brace; in contrast, PVC, CPVC and copper all require elbow joints. A single length of PEX pipe can not handle a sharp 90-degree turn, however, so in those situations, it is necessary to connect two PEX pipes with a 90-degree PEX elbow joint.
  • Direct routing of pipes. PEX can run straight from a distribution point to an outlet fixture without cutting or splicing the pipe. This reduces the need for potentially weak and costly joints and reduces the drop in pressure due to turbulence induced at transitions. Since PEX is flexible, it is often possible to install a supply line directly from the water source to an appliance using just one connection at each end.
  • Greater water pressure at fixtures. Since PEX pipes typically have fewer sharp turns, there is greater water pressure at the sinks and showers and toilets where it is needed.
  • Less materials cost. Cost of materials is approximately 25% of alternatives. One account suggested that the price of copper had quadrupled from 2002 to 2006.
  • Easier installation. Installing PEX is much less labor intensive than copper pipes, since there is no need to use blow torches to solder pipes together, or to use glue to attach pipes to fittings. One home inspector wrote that "Once you've worked with PEX, you'll never go back to that other stinky glue stuff." Builders putting in radiant heating systems found that PEX pipes "made installation easy and operation problem-free." PEX connections can be made by pushing together two matching parts using a compression fitting, or by using an adjustable wrench or a special crimping tool. Generally, fewer connections and fittings are needed in a PEX installation.
  • Reliable. It neither corrodes nor develops so-called "pinhole" leaks.
  • No fire risk during installation. Copper piping required soldering using blowtorches, and there was a risk of flame and heat causing a fire; but with PEX there is virtually no danger from fire. However, there was an unfortunate counter-incident in 2011 in which authorities suspect that six firefighters were injured when a fire melted the plastic PEX pipes, causing water to soak into ceiling insulation, adding greater weight which caused the ceiling to collapse; but the PEX tubing was not blamed as the cause of the fire. Overall PEX piping is much safer to install; according to the U.S. National Fire Prevention Agency, blow torches used for soldering metallic plumbing ranked as one of the "top-ten leading causes of house fires each year."
  • Acceptance by plumbers. There are routinely advertisements for plumbers specifically seeking ones with PEX experience.
  • Ability to merge new PEX with existing copper and PVC systems. Manufacturers make fittings allowing installers to join a copper pipe on one end with a PEX line at the other, as well as have options to reduce or expand the diameter of the pipes.
  • Longevity. The advantageous properties of PEX also make it a candidate for progressive replacement of metal and thermoplastic pipes, especially in long-life applications, because the expected lifetime of PEX pipes reaches 50 years. However, the longest warranty offered by any PEX producer is 25 years.
  • Suitable for hot and cold pipes. A convenient arrangement is to use color coding to lessen the possibility of confusion. Typically, red PEX tubing is used for hot water while blue PEX tubing is used for cold water.
  • Less likely to burst from freezing. The general position is that PEX plastic materials are slower to burst than copper or PVC pipes, but that they will burst eventually since freezing causes water to expand. One account suggested that PEX water-filled pipes, frozen over time, will swell and tear; in contrast, copper pipe "rips" and PVC "shatters". Home expert Steve Maxwell suggested in 2007 that PEX water-filled pipes could endure "five or six freeze-thaw cycles without splitting" while copper would split apart promptly on the first freeze. In new unheated seasonal homes, it is still recommended to drain pipes during an unheated cold season or take other measures to prevent pipes from bursting because of the cold. In new constructions, it is recommended that all water pipes be sloped slightly to permit drainage, if necessary.
  • No corrosion. Copper and iron pipes can experience corrosion leaks but PEX does not have these problems.
  • Environmental benefits. One account suggested that PEX used in radiant heating was better for the environment than a copper choice, although it noted that the pipes were based on petroleum products.
  • Pipe insulation possible. Conventional foam wrap insulation materials can be added to PEX piping to keep hot water hot, and cold water cold, and prevent freezing, if necessary.

Read more at:  http://en.wikipedia.org/wiki/Cross-linked_polyethylene


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8Oct/114

Electric Water Heater Heating Element Troubleshooting and Replacement

Unlike gas water heaters that have gas burners to heat the water, electric water heaters rely upon an upper and lower pair of metal heating elements. These heating elements are made of metal and get hot from electrical resistance, similar to what you would find in an electric cooking range.

As a result of a cold water supply coming in near the bottom of the tank, the lower heating element is the workhorse of the electric water heater. The upper heating element really only contributes when there is a high hot water demand and only serves to heat water in the upper portion of the tank. A constant supply of lukewarm water during a shower is indicative of a defective upper heating element. Short duration hot water supply during a shower is indicative of a defective lower heating element. Replacement heating elements must be of the same style and voltage/wattage rating as the ones presently in the water heater.


To test an electric water heater heating element proceed as follows:

  1. Use an electronic multimeter or multi-tester to test the heating elements in an electric water heater.Turn off power to the electric water heater at the main power panel. Do this by turning off the circuit breaker or fuse powering the heater.
  2. Wait for the water heater to cool, this is very important because the heating elements operate off a thermostat and hot water in the tank will affect electrical flow to the heating elements.
  3. Test for lukewarm to cool “hot” water by opening a hot water faucet and running the water until it is cool.
  4. Remove the access cover panel and insulation covering the heating element terminal block. Fold the insulation outward and away from the heater element.
  5. Loosen the screws holding the wires to each of the two terminal screws and remove the wires.
  6. Test for proper functioning of the heating element by checking for an open or closed circuit (continuity) using the electronic multi-tester. Set the multi-tester to “Ohms” and connect the red lead to one terminal and the black lead to the other terminal on the heating element.
  7. If the ohm reading is 0 on a digital multi-tester or if the needle reads infinity (does not move) using an analog dial, there is no flow of electricity through the element and it needs replacement.
  8. If you get an ohm resistance value using the multi-tester, then the heating element itself is not bad. The problem may be the other heating element or the upper or lower heating unit thermostat.


To remove the heating element proceed as follows:

  1. Shut-off the electric power to the water heater at the main power panel. Do this by turning off the circuit breaker or fuse powering the heater.
  2. Next, drain the electric water heater.
  3. Remove the access cover panel and insulation covering the heating element terminal block. Fold the insulation outward and away from the heater element.
  4. Remove the thermostat cover from the thermostat if necessary. Make sure to disengage the attachment point from the thermostat.
  5. Loosen the screws holding the wires to each of the two terminal screws and remove the wires.
  6. Remove a screw-in type heating element by turning the element counterclockwise with a 1-1/2 inch socket element removal wrench. Remove the existing gasket.
  7. Remove a flange type heating element by removing the four screws holding the element in place. Remove the existing gasket.

To replace the heating element proceed as follows:

  • Clean the area surrounding where the gasket fastens to the tank. It is good practice to remove and sediment at the bottom of the tank if you are replacing the bottom heating element.
  • Make sure the replacement element has the correct voltage and wattage rating. You can find this information on the flange or terminal block of the element or on the water heater’s data plate.
  • Properly place the new gasket onto the heating element and insert the assembly into the water heater tank. Tighten a screw-in type heating element by turning clockwise with the element socket wrench until secure.
  • Close the drain valve on the water heater.
  • Open the nearest hot water faucet to allow the tank to fill completely with water.
  • Keep the hot water faucet open for 3 minutes after obtaining a constant flow of water. This will purge the lines of any excess air and sediment.
  • Check for leaks around the element.
  • Connect the power wires to the electric heating element and make sure they are tight.
  • Replace the thermostat cover.
  • Replace the access cover panel.
  • Completely fill the water heater tank with water. This is critical because running electricity to heater elements that are not immersed in water will destroy the heating element.
  • Turn power to the water heater back on at the main power panel. Do this by turning on the circuit breaker or fuse powering the heater.

Read entire article HERE