Page No 6 of 56 Reznor, RHC21 4000 Installation EN May 2021 D301334 Issue 0
1. Introduction
Isolate any electrical supply to
the heater and controller before
proceeding.
1.1 Basic information
The instructions in this manual apply to the
RHC21 4000 gas-fired air heating modules
installed at an operational ambient temperature
between -15°C and +45°C.
The appliances must be installed in accordance
with the rules in force. Before installation, check
that the local distribution conditions,nature
of gas and pressure and adjustment of the
appliance are compatible.
A permanent electricity supply of 230 volts, 50
hertz, single phase is required.
RHC21 4000 air heater modules are suitable for
use in internal and external air handling units
(when installed internally where the height
above floor level is greater than 1.8 meters
measured to the underside of the appliance they
may be used as a garage air heater).
Model RHC21 4000 air heater modules may
be installed as a Type C room sealed heater
requiring both a combustion air inlet pipe and a
flue pipe (Type C
13
, C
33
or C
53
only) or as a Type
B forced draught heater where the combustion
air is taken from the room space the heater is
installed in and which requires only a flue pipe
exhausting to outdoors (Type B
23
or B
53
only).
All products of combustion must be flued to
outdoor atmosphere.
All models and sizes are available for use
with natural gas with operating temperatures
between 15°C and 40°C.
These instructions are only valid for appliances
designed to operate in Europe. If the country
code and gas category on the appliance
data label does not match the country of
installation or the country codes and gas
categories as shown in this instruction
manual, it will be necessary to contact the
distributor or manufacturer to provide the
necessary information for the modification of
the appliance to the conditions of use for the
country of installation.
Check that the local distribution conditions of
electricity supply, type of gas and pressure of
the appliance are compatible.
The total installation should be installed in
accordance with the rules in force, relevant
National Standards, local regulations,and Codes
of Practice.
When the external control calls for heat, an
electronic control begins the ignition sequence
to provide for a safe start.
Under normal conditions the fan motor runs
constantly and after a call for heat it switches
the heater on through a room or duct stat.
However,in some applications, about 30 seconds
after the call for heat, the fan control relay will
activate the fan motor of the air handler.
The electronic control will supervise the flame
during the entire heating cycle to ensure safe
operation. When the required room temperature
is reached, the main burner will shut down
leaving the fan running to cool down the heat
exchanger. After approximately 45 seconds, the
fan delay relay will turn off the fan (if wired).
All models may only be used when installed
within a closed compartment, e.g. an air
handling unit or using the optional vestibule.
For dimensions refer to figures 1,2 & 3
following. All dimensions are in mm
(25.4mm= 1inch)
Only recognised air handling unit
manufacturers are authorised to
build in the heater module. Please
contact your distributor.
Any other application is forbidden
and dangerous. Failure to comply
can result in severe personal injury,
death and/or property damage.
Note: manufacturer warranties do
not apply in such circumstances.
