IOM GMI 2M & 2ML Nov 2010.doc
16
2.4 Water Connection
All pre-installation work has been completed at the factory. Two water manifolds (inlet and outlet
headers) are provided with the unit. One low water cut-off switch is installed on the outlet
manifold. One high temperature limit switch and one pressure relief valve are installed on the
outlet manifold. A temperature sensor installed on the outlet manifold is connected to the
appropriate terminals in the Riello control box. It is strongly recommended that user install a flow
switch on inlet pipe.
Cold-water inlet and hot water outlet connections are clearly marked on the respective manifolds
of the boiler/water heater. The cold water supply line (in one pass applications), or return water
(in closed loop applications) should be connected to the cold water inlet of the unit. The hot water
supply line should be connected to the hot water outlet of the boiler. Both manifolds have 3”
stainless steel flange, ANSI 150 lbs inlet/outlet connections.
For further information on methods of connecting supply and return water piping to boilers/water
heaters consult available installation and piping guides developed according to local plumbing
codes.
2.5 Condensate Line
Connect 3/4” ABS tubing from the condensate drain “U” trap, directly to the floor drain. Notice
that the line MUST be pitched downward towards the floor drain to avoid traps. DO NOT install
any valve of any type, or any other instrument between the condensate drain “U” trap and the end
of the condensate line.
2.6 Gas Line Connections
The gas train comprises a pressure regulator, low gas pressure switch, solenoid valve, and the main
gas valve. Gas pressure at the inlet to the pressure regulator should always remain in the 8” – 14”
wc range. If higher pressures are present, consult the local gas company or gas installation codes
for installing the appropriate gas pressure regulator. Gas line from the meter to the boiler/water
heater should be of adequate size to prevent undue pressure drop. A manual shut off valve should
be installed in the gas line upstream of the pressure regulator, so that the control instruments (main
gas valve, boiler/water heater gas regulator, and low gas pressure switch) could be easily isolated
and removed, whenever necessary. The valve should be clearly marked, located outside the unit’s
NOTE
¾ To ensure proper flow of condensate, it is recommended to install a
“drain vent” of approximately 1foot height at 0.5-1 foot downstream of
the U trap.
To Next Page
Loading...