If the heater has not been left operational proceed as
follows.
A) Checks before lighting the Air
Heater
The following preliminary checks should be made before
lighting the heater(s)
a) Ensure that the ELECTRICAL supply to the heater is
switched OFF.
b) Check that all warm air delivery outlets are open.
c) Check that the thermostat is set at MAX.
d) Check that the clock control is set to an ON period.
e) Check that any other controls are calling for heat.
B) Lighting the Air Heater
1. Switch on the electrical supply at the isolator
2. If the Limit indicator light comes on press the limit inter-
lock reset switch on the front panel of the heater.
3. The startup sequence will commence. After a short
delay the burners will light and the green ‘ON’ indicator on
the front of the heater will be illuminated.
4. If the burners fail to light the control box will automati-
cally restart the ignition sequence. If after 5 attempts at
ignition the burners have still failed to light the control box
will go to lockout and the red lockout light on the front of
the heater (or on the low level remote reset, MC200 or
Powrtrol RR if fitted) will be illuminated. To restart the
ignition sequence depress the reset button on the low
level reset for about 1-2 seconds.
WARNING: If it is not possible to light the heater
after several attempts, contact the installer or
local service company.
C) To Shut Down the Air Heater
1) For Short Periods:
Turn the room thermostat to the OFF, or set to it’s lowest
setting.
2) For Long Periods:
Complete step 1 above. Wait for 5 minutes and then turn
OFF the electrical supply at the isolator.
D) Description of Operation
Important:
The heater must NOT be controlled
by switching ON and OFF the main electrical
supply to it.
1) Standard Units
The ignition sequence commences each time the external
controls e.g. Time clock, room thermostat etc. call for
heat. The internal exhaust fan will run and, when
sufficient combustion airflow is proved by the air pressure
switch, the ignition spark will be generated, the main gas
valve opens and the burners light. The green ‘ON’ indica-
tor will be illuminated. The heater fan will automatically
start approximately 2 minutes after the burners light.
When the external controls are satisfied the burners will
be turned off and approximately 2 - 3 minutes later the
heater fan will be automatically stopped. If the burners fail
to light the control box will make another four attempts at
ignition.
2) High / Lo & Modulating Units
When the burners are alight, the heat output will be
controlled either to high fire or low fire or, in the case of
modulating units, to any point between high and low fire;
depending on the requirements of the space being
heated and the external controls fitted.
3) Summer / Winter Modes
Certain types of external controls will provide for two
modes of operation i.e.
Summer: The heater fan alone will run at the dictate of the
external controls to provide air movement.
Winter: The heater will operate normally.
4) Overheat Thermostat
This operates if high temperatures within the heater are
detected, the burners are turned off and a Amber indicator
switch light on the front panel is illuminated. NVx10 - 75
units have the thermostat located inside the controls
section. NVx90 - 140 units have an additional thermostat
on the side of the unit at the opposite end to the controls
(either thermostat can go to limit and shut off the burners).
The fault condition must be identified and rectified and the
thermostat manually reset.
When the unit has cooled, push the Amber indicator
switch on the front panel to reset the limit thermostat inter-
lock relay, the red indicator light will go out and the unit is
operational again.
Note:
The limit thermostat(s) can only be reset
once the unit has cooled down.
Unless the cause of the fault condition is readily
obvious, for example a power cut whilst the
heater was operating, a service engineer should
be contacted.
E) Maintenance
To maintain efficient, reliable and safe operation of the
heater it must serviced by a qualified person at least
annually and preferably at the end of the heating season.
F) IMPORTANT
Free access must be maintained to and around the heater
for servicing purposes and the air supply to the heater
must not be restricted in any way. Combustible materials
must not be stored adjacent to the heater.
If at any time a gas leak is suspected, turn OFF the gas
supply at the meter and contact the local gas undertaking
immediately.
All Powrmatic heaters use gas and electricity to power
them, they may also contain moving parts such as pulleys
and belts. It would be hazardous to tamper with or attempt
to service unless you are a competent person in the field
of Gas and Electrical work.
If you have any safety questions reference the servicing
and installation of any of our heaters please do not
hesitate to contact our head office for expert advice. Your
safety is paramount to us.
Gas Safety (Installation & Use) (Amendment) Regula-
tions
It is law that all gas appliances are installed,
adjusted and, if necessary, converted by qualified
persons* in accordance with the current issue of
the above regulations. Failure to install applianc-
es correctly can lead to prosecution. It is in your
own interests and that of safety to ensure that the
law is complied with.
* An approved class of person listed on the gas
safe register.
NVX Range Users, Instructions & Service Instructions Issue 5.5 August 2015 Page 5
1.1 Introduction
The NVx range are highly efficient, gas fired, fanned
circulation air heaters that cover heat outputs of 10kW to
140kW, have a closed combustion circuit and are
supplied complete with a flue system. They are certified
for use on Natural Gas, Group H - G20, and Propane -
G31 only. Appliance Categories are Cat II2H3P (GB, IE).
The heaters are designed to be suspended from suitable
roof points or alternatively to be mounted on purpose
designed brackets and are intended primarily for heating
commercial or industrial premises. All variants, with the
exception of NVx/EA units, are for internal use only.
NVx heaters feature a closed combustion circuit and
have an internal exhaust fan, mounted downstream of
the heat exchanger, to evacuate the products of combus-
tion and draw in air for combustion. The air heater must
be connected to a flue system that is approved by Powr-
matic Ltd.
They may be used where the atmosphere inside the
premises could be contaminated e.g. Dust, oil mist etc.
but the heaters are not airtight and therefore may not be
used in areas classified as hazardous as defined in BS
5345: Part 2 or areas subjected to significant negative
pressures due to extract systems.
NVx/F heaters have an axial fan assembly fitted at the
rear to circulate the air being heated through the formed
tube heat exchanger. NVx/CCF units are supplied with a
centrifugal fan and NVx/D units for use with ducted
systems where the air moving fan is by others or a
centrifugal fan section is used adjacent to or remote from
the heater. NVx/DH units are for use in air handling units
and NVx/EA units are for siting externally.
Heaters are fitted as standard with inshot burners, a fully
automatic control for ignition, flame sensing, gas supply
control and safety functions, an internal exhaust fan,
main air fan (/F and /C models), and fan/limit thermostat.
Options include High/Low or Modulating burner controls,
inlet duct connection, outlet duct connection, 30°, 45°
head, 90° outlet bend, vertical/horizontal outlet louvre
assembly and a full range of modular duct components.
IMPORTANT
Service and Maintenance Engineers shall
ensure that replacement items are fitted, adjust-
ed and set in accordance with the data and detail
set out in these instructions. If in doubt consult
Powrmatic Technical Department.
Gas Safety (Installation & Use) Regulations
1998
It is law that all gas appliances are installed,
adjusted and, if necessary, converted by quali-
fied persons* in accordance with the current
issue of the above regulations. Failure to install
appliances correctly can lead to prosecution. It is
in your own interests and that of safety to ensure
that the law is complied with.
* An approved class of person listed on the gas
safe register.