Install Instructions

Installing the Viega PureFlow PEX Tubing System
61 of 88
IM-PF 724596 1021 PureFlow Water System (EN)
11.7 Water Heaters
Viega PureFlow PEX tubing should not be connected directly to gas-󶈵red
water heaters. The high temperatures of these appliances can damage
the tubing.
When connecting a Viega PureFlow system to a gas-󶈵red 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, Viega PureFlow PEX tubing may be connected directly to
electric water heaters and used for hot water recirculation lines that do
not come within 6" of the gas heater vent.
Viega PureFlow PEX may be used to connect directly to instantaneous/
tankless water heaters or other hot-water-producing devices. However,
consult the Authority Having Jurisdiction and the manufacturer’s
recommendations for use with plastic tubing and ensure temperature
and pressure do not exceed the maximum ratings of the tubing. If the
inlet or outlet water piping is in a position such that it may be exposed to
temperatures above 180° F, an appropriate connector of su󶈷cient length
should be used to separate the plastic pipe from the heat source.
11.8 Heaters, Flues, Vents, and Recessed Lights
Keep Viega PureFlow PEX tubing a MINIMUM of 12" vertically and 6"
horizontally from sources of high heat such as gas 󶈶ue vents, heating
appliances or electric motors.
Concerning recessed lighting (including low-voltage types) and proper
installation clearance, Viega recognizes the following types of lighting
󶈵xtures: Type IC or Inherently Protected, which allow direct contact with
thermal insulation and other combustible materials, and Type Non-IC,
which require a minimum clearance of 3" to thermal insulation. If room
does not allow for the minimum clearance spacing speci󶈵ed by Viega,
then the PEX tubing must be insulated with a suitable pipe insulation
capable of withstanding the speci󶈵c maximum temperatures generated
by the 󶈵xture. Minimum clearance between any pipe insulation and 󶈵xture
shall be per the requirements of the 󶈵xture type and local building codes.
Forced air heating ducts and PVC power vent 󶈶ues are not generally
considered sources of high heat. These areas of installation should be
rechecked after further construction and other mechanical systems have
been installed.
In cases where light leakage (direct beam) from a UV-generating light
source (special lighting or heating- type lamps) is possible, tubing must
be adequately protected with light-blocking insulation.
12"
6"