Measuring Gas Pressure - Bosch 520-HN-N User Instructions

3.7

Measuring gas pressure

Connecting manometer
B Shut off gas.
B Remove front cover and locate inlet gas pressure
measuring point on the left side, see Fig. 15.
B Loosen screw from test point on the left side and
connect manometer tube on test point.
1
Fig. 15 Gas pressure measuring point
1 Inlet tap
Static pressure test
B Turn gas supply back on.
B Record static gas pressure reading on back page of
manual.
Operating pressure test
B Turn on all hot water taps served by the water heater.
B Turn flow control (right knob) fully clockwise.
B Turn power adjustment (left knob) fully counter-
clockwise.
B Turn power adjustment knob fully clockwise.
B Operate all other gas appliances on same gas piping
system at maximum output.
B Record operating gas pressure reading on back
page of manual.
Gas pressures lower than 5.7" W.C. for Natural Gas or
10.5" W.C. for LP Gas will result in insufficient degree
rise to the hot water being used and must be corrected.
See Gas Line Sizing under chapter 3.6.
3.8 Water connections
When facing the heater, the ½" cold water inlet is on the
bottom right and the hot water outlet is on the bottom
left.
B Install unions and shutoff or isolation valves
when connecting plumbing to the water
heater. This will facilitate any necessary
cleaning and servicing.
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Although water piping throughout the structure may be
other than copper, we require that copper piping or
suitably rated stainless steel flex line piping be used for
at least three feet before and after the heater (follow
local codes if more stringent). Never sweat any rigid
piping directly to or beneath the water connections or
damage can occur to the internal water valve from
heating of the pipe. Plastics or other PEX type plumbing
line materials are not allowed for connecting directly to
the water heater. Keep water inlet and outlet pipes to no
less than ½" (12.7mm) diameter to allow the full flow
capacity.
It is recommended that all hot water piping be properly
insulated to avoid heat loss.
If the cold and hot connections to the heater are
reversed, the heater will not function. Be certain there
are no loose particles or dirt in the piping. Blow out or
flush the lines before connecting to the water heater.
Full port valves must be installed on both the cold water
supply and hot water outlet lines to facilitate servicing
the heater (see Fig. 16). For installation on a private well
system with the use of a pressure tank, the lowest
pressure range setting recommended is 30-50 psi
(2.07 and 3.45bar).
Connecting the pressure relief valve (PRV)
A listed pressure relief valve must be installed at the
time of installation. No valve is to be placed between
the PRV and the heater. No reducing coupling or
other restriction may be installed in the discharge line.
The discharge line must be a minimum of 4" above a
drain and installed such that it allows complete drainage
of both the PRV and the line.
The location of the PRV must be readily accessible for
servicing or replacement, and be mounted as close to
the water heater as possible. See Fig. 16. To install the
PRV, a suitable fitting connected to an extension on a
"T" fitting can be sweated to the hot water line.
Support all piping.
Fig. 16 Plumbing Connections and Pressure Relief
Valve
Installation instructions
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