Page No 38 of 56 Reznor, RHC21 4000 Installation EN May 2021 D301334 Issue 0
RHC21 model 4100-12 remove combustion fan
to reveal gas valve fixing screws
RHC21 models 4100-12 gas valve fixing screws
6. The gas supply pipe with flange can be
removed by unscrewing the 4 fixings. Do not
lose the o-ring seal.
RHC21 4000 all models except 4100-12 gas
valve inlet flange assembly. Note that there
are two gas valves on RHC21 4125M15 and
4150M18
RHC21 model 4100-12 gas valve inlet flange
assembly
7. Refit gas valve in reverse order ensuring the
o-ring is fitted between the gas valve and
venturi.
8. Follow start up and commissioning
procedures.
7.2 Venturi cleaning and replacement
1. Clean the venturi inlet with a lint free cloth.
2. For replacement follow steps 1 to 5 from gas
valve replacement.
3. Separate the venturi from the combustion
fan by removing the fixings (3 screws
RHC21 4000 all models except 4100-12
and 6 screws RHC21 models 4100-12 as
per the photographs shown under gas valve
replacement).
RHC21 4000 all models except 4100-12 venturi
RHC21 model 4100-12 venturi
6 off Fixing
screws
4 off Fixing
screws
O ring
O ring
Throttle
Screw
Fixing
Screws
Throttle
Screw
