wwilson3 wrote:Can pex be connected directly to the tank with out 18 inches of solid pipping ( electric or gas)
Electric: Yes but ... the following items must also be followed.
Gas: No but ... in addition to the following items, such as regarding the clearance from Type B Gas Vents being shown as only 1 inch, keep in mind that the clearance from the draft hood is 6 inches just like the clearance from single wall vents is and the PEX must be kept a minimum of 6 inches away from the draft hood as measured from the lip and sloping surface of the draft hood.
Also keep in mind that in garages the garages are filled with direct sunlight when the garage doors are open or when there are windows which allow sunlight into the garage, and that PEX is not to be exposed to direct sunlight.
Also keep in mind that attics with off-ridge vents, wind turbines, and some other types of vents light direct sunlight into the attic and the PEX is not allowed in direct sunlight.
Keep in mind that PEX connected to water heaters in garages may be susceptible to "organic chemicals, pesticides, strong acids or strong bases to come into contact with Uponor PEX" from items stored on the water heater.
When reading the following list keep an open mind as to what each item applies to, some of which I addressed above.
From the Uponor PEX installation guides:
- Handling Guidelines for PEX Tubing
- - Although not comprehensive, the following highlights the most common guidelines to use when handling Uponor PEX tubing:
- - - Install Uponor systems according to the manufacturer's installation instructions. Failure to follow the instructions and installation guidelines can result in the failure of Uponor systems.
- - - Do not use Uponor PEX where temperatures and pressures exceed ratings.
- - - Do not use or store Uponor PEX where it will be exposed to direct sunlight for more than 30 days.
- - - Do not weld, glue or use adhesives or adhesive tape with Uponor PEX.1
- - - Do not apply open flame to Uponor PEX.
- - - Do not install Uponor PEX within 6 inches of any gas appliance vents, with the exception of double-wall B-vents, which have a minimum clearance of 1 inch.
- - - Do not install Uponor PEX within 12 inches of any recessed light fixtures, unless the PEX line is protected with suitable insulation.
- - - Do not solder within 18 inches of any Uponor PEX tubing in the same water line. Make all sweat connections prior to making the fitting connection.
- - - Do not use Uponor PEX to convey natural gas.
- - - Do not install Uponor PEX between the tub/shower valve and tub spout.
- - - Do not use Uponor PEX for an electrical ground.
- - - Do not spray on or allow organic chemicals, pesticides, strong acids or strong bases to come into contact with Uponor PEX.
- - - Do not use petroleum or solvent-based paints on Uponor PEX.
- - - Use only approved and appropriate firestop materials with Uponor PEX.
- - - Do not allow rodents, insects or other pests to come into contact with Uponor PEX tubing.
- - - Do not subject Uponor PEX to impact.
- - - During remodeling or ceiling repair, implement appropriate precautions to protect the tubing from damage.
- - - Uponor PEX and fittings are intended for use in systems outlined on page 1.
Viega PEX (formerly Vanguard PEX) installation manual states:
- 10.10 Water Heaters
- - PureFlow tubing should not be connected directly to gas-fired water heaters. The high temperatures of these appliances can damage the tubing. When connecting a PureFlow system to a gas-fired water heater, install a minimum of 18" of metallic piping between the water heater and tubing, keeping tubing more than 6" away from the vent pipe. Where local code allows, PureFlow tubing may be connected directly to electric water heaters and used for hot water recirculation lines which do not come within 6" of the gas heater vent.
- - ViegaPEX may be used to connect to instantaneous / tankless water heaters or other hot water producing devices. However, consult manufacturer’s recommendations for use with plastic tubing and ensure temperature and pressure do not exceed the maximum ratings of the tubing.
- 10.11 Heaters, Flues, Vents and Recessed Lights
- - Keep PureFlow PEX tubing a MINIMUM of 12" vertically and 6" horizontally from sources of high heat such as gas flue vents, heating appliances or electric motors. (then this continues on about recessed lights, etc.)
Uponor's installation guide is not a clear and concise, in some ways, not a complete as, Viega PEX, thus applying the Viega PEX requirements should provide a good standard to use.