Reznor, RHC21 8000 Installation EN May 2021 D301319 Issue 0 Page No 23 of 52
1 - Offset adjustment
2 - Inlet pressure measuring point
3 - CO
2
adjustment point (throttle)
4 - Offset pressure measuring point
Figure 7 : Gas valve adjustment models
RHC21 8045-09, 8060-12, 8075-09, 8125M15
(2 off), 8150M18 (2 off) and 8175M21 (1 off)
Models RHC21 8100-12, 8175M21 (1 off)
and 8200M24 (2 off)
To adjust the throttle use a 4mm hex key on the
screw located on the venturi. Rotate clockwise
to increase %CO
2
. Rotate counter clockwise to
decrease %CO
2
.
To adjust the offset, use a T40 torx key to
remove the protection cap on the gas valve.
Rotate counter clockwise to decrease pressure /
%CO
2
and rotate clockwise to increase pressure
/ %CO
2
. Refit cap after adjustment.
1 - Offset adjustment
2 - Inlet pressure measuring point
3 - CO
2
adjustment point (throttle)
4 - Offset pressure measuring point
Figure 8 Gas valve adjustment models
RHC21 8100-12, 8175M21 (1 off) and
8200M24 (2 off)
5.8 Gas conversion
RHC21 8000 heaters are designed to operate
on natural gas types G20, G25 and G25.3.To
modify for use on an alternative listed gas type,
follow the commissioning guide and refer to the
Combustion Data table overleaf for approximate
throttle turns from G20 setup.
The data label needs to be updated after
conversion. Using permanent ink place an 'X'
in the box above the relevant gas type column
to indicate the new gas setting. Obscure any
previous indication.
Upon completion of conversion recommission
the heater. Refer to the commissioning section
for more details.
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2
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