page no. 18 of 44
HEMNVx & HEMSL Range Users, Installation & Servicing Instructions Doc Ref M103 issue 3.6 Mar 2020.
Only flue systems supplied through Powrmatic Ltd may be
used with HEM modules. The flue outlet socket must be
connected via the provided flue system to outside air.
The maximum permitted length of flue system is shown in
duties on page 6 and 7. If an offset is required, two sets of
45° bends should be used each set being equivalent to 0.5m
of flue length. 90° bends may be used but each set will be
equivalent to 1.0m of flue length.
All outer joints must be finished with the provided locking
bands. A smear of silicon grease to the inside of sockets
will assist in fitting components together.
All flue and combustion air ducts must be supported
independently of the air heater.
The flue or flue/combustion air terminal must not be
installed so as to be less than:
300mm below an opening e.g. window, air brick etc.
200mm below eaves or gutter.
300mm from an internal or external corner.
1200mm from a surface facing the terminal.
1500mm vertically from another terminal on the same wall.
300mm horizontally from another terminal on the same wall.
The flue must terminate in a freely exposed position and be
sited to prevent the products of combustion entering any
opening in a building in such concentration as to be
prejudicial to health or a nuisance.
Twin Wall Flue can also be used
If, given the application and usage of the module, it is
considered that condensate will be formed at times then
the condensate drain pipe at the base of the unit must be
fitted with an external trap, equivalent to that shown below,
the outlet of which must be run to a local drain point. The
trap can be a proprietary item or fabricated using standard
domestic 32mm waste water fittings in which case ensure
that the dimensions shown are adhered to.
The trap must be filled with water after installation and
before the heater is commissioned. The trap and associated
pipe work must be protected from freezing. If drainage
under gravity is not possible a condensate pump should be
used and installed following the manufacturers instructions.
Only a suitably qualified operative can complete the
electrical installation and must observe the rules in force.
All electrical connections are made to the screw terminals
in the control section and should be in accordance with
the terminal markings and the wiring diagram for the
module.
Module(s) must be earthed.
A lockout indicator light and reset button are fitted in
the control panel. If required these functions can be
duplicated remotely from the module.
The module(s) does not include the main air moving fan.
Direction of airflow may be either R-L or L-R for vertically
orientated modules or from top to bottom or bottom to
top for horizontally orientated units.
The main fan must be interlocked to the module
by a pressure switch or sail switch or equivalent
so that if the main air flow fails for any reason
the module(s) is shut down.
The minimum airflows specified in section 1.2 must not
be reduced.
The airflow across the module(s) should be kept at a level
that ensures condensation in the tubes will not occur with
the remainder of the air flow passing through a bypass
section to be mixed with the heated air downstream of
the module(s).
Please contact the Powrmatic office to obtain the
appropriate bypass dimensions to suit the specific heater.
The main fan controls must ensure that when
the module is tuned off, i.e. the heat demand is
satisfied, the main fan continues to run for 3-4
minutes to dissipate the residual heat from the module.