Powrmatic OUH series User, Installation And Servicing Instructions

The OUH Range

CE

Users, Installation and Servicing

Instructions

WARNING: THIS APPLIANCE MUST BE EARTHED

OUH Range Users, Installation & Servicing Instructions Issue 4 March 2010

Certificate of Guarantee

Dear Customer

This is to certify that this appliance is guaranteed for two years including parts
and labour from the date of original commissioning.

The heat exchanger, where fitted, is guaranteed (parts only) for a further eight
years, chargeable on a sliding scale basis, price relative to age.

To make a claim

In the first instance you must contact your appliance supplier, or installer and
provide:-

1. The appliance type and serial number.

2. The original commissioning documentation.

3. As much detail as possible on the fault.
Your supplier, or installer will then contact Powrmatic to make a guarantee claim
on your behalf.

Conditions of Guarantee

1. The appliance must have been installed by a competent recognised installer,
and in accordance with the manufacturers instructions, building regulations
and local regulations.

2. The appliance has been professionally commissioned.

3. The appliance has been maintained on a yearly basis by a competent

servicing company.

4. The appliance has been used in accordance with the manufacturers

instructions.

5. The correct specification fuel has been used

6. No unauthorised repairs or modifications have been made.

7. Powrmatic ‘General Conditions of Sale’ have been observed.

8. Except for the obligation of Powrmatic Ltd to perform warranty repairs during
the guarantee period, Powrmatic will not be liable in respect of any claim for
direct or indirect consequential losses, including loss of profits or increased
costs arising from loss of use of the appliance, or any event arising there from.

Exclusions

1. Gaskets and fan belts are not included in the guarantee

Powrmatic Ltd, Hort Bridge, Ilminster, Somerset, TA19 9PS

tel: [phone] fax: [phone]

web: www.powrmatic.co.uk

Important: This certificate must

be kept with the appliance

Users Instructions

1. 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.
f) Ensure that the Summer/Winter switch is in the Winter

position.
g) Check that the overheat reset button has not operated.

2. Lighting the Air Heater

NOTE: If it is not possible to light the heater after 2/3 attempts
contact the local service company.

1. Switch on the electrical supply at the isolator and the burner
start-up sequence will commence. The burner air fan will run
and after a pre purge period of approximately 30 seconds the
ignition spark will be generated and the oil valve opened.

The main burner will then start.
NOTE: If the burner fails to light it will go to lockout and the

lockout indicator / reset button on the burner control box will
be illuminated. To restart the burner push the lockout reset
button.

3. To Shut Down the Air Heater

3.1 For Short Periods:

Turn the room thermostat to the OFF or lowest setting.

3.2 For Long Periods:

Turn the room thermostat to the OFF or lowest setting.
Wait approximately 4-5 minutes for the main air fan of
the heater to stop running and the turn off the oil supplies

and electric supplies to the heater.

4. Description of Operation

Important: All heaters must be controlled by the fitted external
controls and not by use of the main switch in the electrical
supply to the heater.

The burner start up sequence will commence when the controls
e.g. Timeclock, room thermostat etc. call for heat. The burner
air fan will run and after a pre purge period the burner will light.

Approximately 2/3 minutes after the burner lights the heater
fan will automatically start. When the external controls are
satisfied the burner will be turned off and approximately 4/5
minutes later the heater fan will automatically stop.

4.1 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.

the fan will start and stop automatically in conjunction with the
burner. See Section 4.
ii) Limit Thermostat Reset
In the event of a fault that causes the temperature of the air

leaving the air heater to rise significantly e.g. Blocked air inlets,
the limit thermostat will operate to shut down the burner.
Remove the cause of the fault, wait 10 minutes and then reset
the thermostat by pushing the red reset button (Refer to Figure
below) .If the limit thermostat continues to operate turn off the
air heater and call a service engineer.

Limit Thermostat

PUSH TO

RESET

Red

reset

button

White

Fan

button

PUSH MAN

PULL AUTO

H on e yw ell

6. Maintenance

Regular servicing is essential to maintain efficient, reliable and
safe operation of the heater. Users are strongly recommended
to have the heater serviced by a qualified person at least annually
and preferably at the end of the heating season.

7. 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.

All Powrmatic OUH heaters use oil and electricity to power
them, they may also contain moving parts such as pulley belts.
It would be hazardous to tamper with or attempt to service unless
you are a competent person in the field of Oil 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.

5. Fan and Limit Control

The fan and limit controls are mounted on the top of the air
heater.

i) Main Air Fan MAN / Auto
When the white button (Refer to Figure following) is pushed

in the fan will run continuously i.e not controlled by any external
controls e.g. Timeclock. When the white button is pulled out

Installation & Servicing Instructions

C O N T E N T S

Section Title Page

1 Introduction 1
2 Technical Data 2
3 General Requirements 4
4 Installation of Heater 5
5 Air Distribution System 7
6 Commissioning & Testing 7
7 Servicing 7
8 Wiring Diagram 9
9 Short List of Parts 9

Figure Title Page

1. Limit Thermostat 8

Table Title Page

1. Dimensions 3

2. Specifications 3

3. Electrical Loadings 1ph 3

4. Burner Settings - 35sec Oil 3

1. INTRODUCTION

The Powrmatic OUH Range is a range of oil fired forced
draught, closed flue, fanned circulation air heaters having an
output range of 20kW to 60kW .
The heaters are designed for suspension from suitable roof
points, or alternatively mounted on purpose designed wall
brackets, and are intended for heating commercial or
industrial premises.
The OUH-F has an axial type fan assembly fitted at the rear
of each heater to circulate the air being heated across the
combined combustion chamber/ heat exchanger. A centrifugal
fan variation is presented in the OUH-C range for ducted
applications. The OUH-D range, in having no fan fitted,
allows for ducted use where the air moving unit is remote
from the heater.
All units are fired with a forced draught packaged oil burner
complete with all necessary safety controls. Each air heater
must be connected to an individual closed flue system only.

1

2. TECHNICAL DATA

OUH20/F

EF F

OUH20/C

B

Front View

G

H

Front View

M

C

D

A K

Side View

Rear View

J

L50mm

Side View

Rear View

OUH30, 45 & 60/F

B

Front View

OUH30, 45 & 60/C

G

M

C

E F

A K

Side View

D

Rear View

H

Front View

J

50mm L

Side View

2

Rear View

Table 1. Dimensions

Model

OUH 20

Type

F

A B C D E F G H J M

668

555 610 100 465 101 549

C

OUH 30,

45 & 60

F

780 847 125 490 276 490

C

Note: D is the nominal flue diameter.

Table 2 - Specifications

HIGH FIRE

MODEL

OUH20

OUH 30

OUH 45

OUH 60

INPUT

(Net)

F

21.92 20.0 0.2601

C

F

32.15 30.0 0.3902

C

F

49.40 45.0 0.5203

C

F

65.57 60.0 0.6503

C

OUTPUT

kW m³/s Pa kW

FUEL

INPUT

kg/h

1.85

2.71

4.16

5.53

AIR

VOLUME

THROW

m

8.5

N/A

16.1
N/A

25.3

N/A

34.1
N/A

N/A N/A

410

N/A N/A

636 418

K

85

N/A

165

N/A

L

N/A

370340

N/A

494

MAXIMUM

DUCT

RESISTANCE

N/A 0.040 53

140

N/A
187 0.750 142
N/A 0.412 126

100 0.750 142

N/A 0.412 126

50 0.750 142

FAN

MOTOR

0.250

0.120

NOISE
LEVEL

dB(A) @ 3m

46

N/A

54

N/A

52

N/A

53

N/A

270

270975

WEIGHT

kg

91.5

126

Table 3

Electrical Loadings 1ph

/F Models /C Models

MODEL

OUH 20

OUH 30

OUH 45

OUH 60

NOMINAL

MOTOR

R.P.M.

900

1400

PLATE

AMPS

(A)

START

AMPS

(A)

RUN

AMPS

(A)

FUSE

RATING

(A)

0.18 0.34 0.16 2.8 4.2 2.10

0.54

0.31

0.89

1.40 0.90 4.0 15.0 7.0

4.50 1.00 4.0 15.0 7.0

2

920

4.50 1.00

PLATE

AMPS

4.0 15.0 7.0

Table 4 Burner Settings - 35sec Oil - Net CV (Hi) = 42.69MJ/kg

Riello Burners
Nozzle Pump Head Setting Combustion Nominal
Model Type Make Size Angle Type Pressure No. Postion Air Setting CO
US Gal ° bar
OUH 20 3GB Danfoss 0.50 60 S 9.5 N/A Fixed 2.0 12.5
OUH 30 G10 Danfoss 0.60 45 S 14.3 1.0 N/A 1.5 12.8
OUH 45 G10 Danfoss 1.00 45 S 12.2 3.0 N/A 2.0 12.0
OUH 60 G10 Danfoss 1.25 45 S 15.6 3.0 N/A 5.0 12.0

(A)

START

AMPS

(A)

RUN

AMPS

(A)

FUSE

RATING

(A)

3

5

%

2

3

3. General Requirements

3.1 Related Documents

Installation of air heaters must be in accordance with the relevant
requirements of:
BS 5410: Part 2: 1978 Code of Practice for Oil Firing
Installations of 45kW and Above
The Building Regulations
The I.E.E. Regulations
It should also be in accordance with relevant requirements of
the local authority and fire authority, in addition the following
British Standard Codes of Practice must be observed
CP.3 Ch IV Precautions Against Fire Part 2 Shops and
Departmental Stores Part 3 Office Buildings,
and the relevant publications of OFTEC.

Refer also to the detail provided in the burner handbook
regarding
pipe sizing. These must be generally in accordance with B S
799 Part 3 and BS 5410 Part 2.
Particular attention is drawn to the following:

a) Pipe jointing compounds must be capable of withstanding

the solvent action of the fuel oil under all operating
temperatures and pressures. Jointing compounds containing
oil shall not be used. Hemp and other fibrous materials shall
not be used as packing for screwed joints.

b) Soft solder copper tube fittings and galvanised pipes and

fittings must not be used.
e) Oil lines must be completely air-tight.
d) The pump suction must not exceed a maximum of 0.4 bar

(30cm Hg). Beyond this limit gas may be released from the

oil.

3.2 Location

The location chosen for the air heater must permit the provision
of a satisfactory flue system and an adequate air supply. The
location must also facilitate ease of servicing and satisfactory
air circulation around the heater.
The air heater must be installed strictly in accordance with any
fire regulations or insurance company's requirements
appertaining to the area in which the heater is located, particularly
where special risks are involved such as areas where petrol
vehicles are housed, cellulose spraying areas, and wood working
departments etc.
The air heater must be installed either:
(a) suspended by chains or straps of adequate strength to
safely carry the weight of the unit and ancillary equipment
or
(b) On specifically designed cantilever brackets from a non­ combustible wall or
(c) On a level non-combustible surface which is capable
of adequately supporting the weight of the air heater and
any ancillary equipment.
The heater must not be installed in conditions for which it is
not specifically designed e.g. highly corrosive atmospheres,
vitiated atmospheres, or where adverse wind conditions may
be experienced. Where the location of the heater is such that it
might suffer external mechanical damage e.g. from overhead
cranes, fork lift trucks etc. it must be suitably protected.
Any ducting should be kept as short and direct as possible having
regard to the distribution of the heated air.
Any combustible material adjacent to the heater and flue systems
must be so placed as to ensure that its temperature does not
exceed 65°C (150°F).

3.3 Oil Supply

3.3.1 Main Storage Tank and fittings

Construction and installation should be in accordance with:
(a) BS 5410 Part 2 Section 6
(b) BS 799 Part 5
(c) BS 1563 and BS1564
The latter three standards apply to cast iron sectional, mild steel
sectional, and mild steel welded tanks respectively and therefore
must be applied appropriately.

3.3.2 Service Tanks and fittings

3.3.2.1 Construction

These should be designed and constructed in accordance with
BS 799 Part 5

3.3.2.2 Installation

The installation should be in accordance with:- BS 5410 Part 2.
In addition the service tank installation must comply with local
regulations and by-laws and with the requirements of insurance
companies

3.3.3 One Pipe System (Storage to burner)

3.3.3.1 General

3.3.3.2 Single Pipe System - Gravity Feed

Warning: The burners are supplied adjusted for a single pipe
system. If the burner is to be used on a twin pipe system the
Internal bypass plug of the burner oil pump must be fitted. Refer
to the burner instruction booklet.
Ideally the return pipe should terminate within the oil tank at
the same level as the suction line, both being below the minimum
oil level.

3.3.4 Fire Valve

It is recommended that the fire valves should be installed as
follows:

1. Main storage to service tank supply (if applicable)

2. Main storage to burner supply

3. Service tank to burner supply (if applicable)
Fire valves should be installed generally in accordance with the
requirements of BS 799: Part 5. The fire valve should be situated
in an easily accessible position as near the tank as possible and
where practicable within the boundary of the tank chamber or
catchpit retaining wall.

3.4 Flue System

The flue system should generally be in accordance with
BS 5410 Part 2.
Materials used for the flue system should be mechanically robust,
resistant to internal and external corrosion, noncombustible and
durable under the conditions to which they are likely to be
subjected. Prevention of condensation within the flue should
be an important factor in the design of the flue system. In order
to minimise condensation the use of doublewalled flue pipe or
insulation is recommended.
Where condensation in the flue is unavoidable, or rain ingress
is possible, provision must be made for a condensate drain
connected to a suitable drain or gully. The condensation pipe
from the flue to the disposal point should be of non-corrodible
material of not less than 22mm (¾ in) size.
Facilities should be provided for disconnecting the flue pipe
from the air heater for inspection and servicing purposes. Bends
with removable covers should be fitted for inspection and
cleaning purposes where considered appropriate.
The flue should terminate in a freely exposed position and must
be situated such that products of combustion do not enter any
opening in a building in such concentration as to constitute a
health hazard.

3.5 Air Supply

Where the air heater is to be installed in the space to be heated
it requires the space containing it to have a permanent air vent
direct to outside air. The air vent should have negligible
resistance and must not be sited in any position where it is likely
to be easily blocked or flooded, neither should it be positioned
adjacent to an extraction system carrying flammable vapour.
The air supply requirement that follows is related to the
maximum rated heat input of the heater, or heaters if more than
one is installed in the same space.

4

Total Input Rating Air Vent Area
of Air Heaters (Air direct-from outside)
Up to 60kW 4.5 cm²/kW in excess of 7kW
From 60kW up to 730kW 4.5 cm²/kW
Where the air heater is to be installed in a plant room, the heater
requires the plant room housing it to have permanent air vents
communicating directly with the outside air, at high and low
level. Where communication with the outside air is possible
only by means of high level air vents, ducting down to floor
level for the lower vents should be used. Air vents should have
negligible resistance and must not be sited in any position where
they are likely to be easily blocked or flooded, neither should
they be positioned adjacent to any extraction system carrying
flammable vapour.
Grilles or louvres should be so designed that high velocity air
streams do not occur within the plant room.
The air supply requirements stated below are related to the
maximum rated heat input of the air heater(s). The minimum
free area requirements of the air vents is given below.
Total Input Rating Position of Air Vent Areas
of Air Heater(s) Vents (Air direct from outside)
Up to 730kW High Level 4.5cm²/kW
Low Level 9.0 cm²/kW

3.6 Air Distribution System

Where single OUH units are required to cover a large floor area,
and in buildings with high roof or ceiling heights Calecon
thermal economiser units should be fitted to ensure even heat
distribution and minimise stratification.
Care should be taken to avoid impeding the air throw with
racking, partitions, plant or machinery etc. Various outlet
configurations are available as optional extras to modify the air
throw pattern to suit particular site conditions.
For ducted units all delivery and return air ducts, including air
filters, jointing and any insulation or lining must be constructed
entirely of materials which will not contribute to a fire, are of
adequate strength and dimensionally stable for the maximum
internal and external temperatures to which they are to be
exposed during commissioning and normal operation.
Where inter-joist spaces are used as duct routes they should be
suitably lined with a fire-resisting material.
A full and unobstructed return air path to the air heater(s) must
be provided.
If the air heater(s) is installed in a plant room the return air
intake(s) and the warm air outlet(s) from the heater(s) must be
fully ducted, into and out of the plant room to avoid interference
with the operation of the heater.
The openings in the structure of the plant room through which
the ducting passes must be fire stopped.
Care must be taken to ensure that return-air intakes are kept
clear of sources of smells and fumes, and where there is any
possibility of pollution of the air by dust, shavings etc.,
precautions must be taken to prevent contamination.
If necessary suitable barrier rails should be provided to prevent
any combustible material being placed within 900mm of the
outlets.

3.7 Electrical Supply

Wiring external to the air heater must be installed in accordance
with the I.E.E. Regulations for Electrical Installations and any
local regulations which apply.
All standard heaters are supplied by 230V - 1ph, 50Hz. The
method of connection to the main electricity supply must:-

- facilitate the complete electrical isolation of the unit(s)

- be in a readily accessible position adjacent to the unit(s)

- serve only the unit(s)

- have a contact separation of at least 3mm in all poles. See the
accompanying wiring diagram for the heater electrical
connections
OUH units can also be supplied for 400V 3N, 50Hz.

4. Installation of Air Heater(s)

4.1 General

The air heater will be delivered to site pallet mounted and
protected by plastic sheeting.
Whichever method of mounting the air heater is used the
following minimum clearances for installation and servicing
must be observed:
Right-hand side (looking at front of heater) 0.5m
Left-hand side (looking at front of heater) 0.5m
Top of burner to ceiling 1.0m
Rear of heater to nearest wall 0.4m
In order to achieve the desired performance levels it is
recommended that the installation height (floor level to base of
unit) is between 2.5m and 5.0m.
If the heater is to be base mounted it may be stood directly on
the platform, provided it is of a suitable noncombustible material
and does not extend past the front edge of the heater.
For multi-heater installations the following minimum distances
between units must be observed.
Between units, side to side 3.0m
Between units, back to back 3.0m

4.2 Fitting the Air Heater

The air heater may be installed either:
(a) Suspended by steel chains, rods or straps.
(b) On specifically designed cantilever brackets from a
non-combustible wall.
(c) On a level non-combustible surface providing the platform
does not extend past the front edge of the heater.
Whatever method of instalation is used it must be capable of
adequately supporting the weight of the unit (See Table 2) and
allowance must be made for any ancilliary equipment. Before
installing the heater any existing trusses, walls brackets etc.
must be inspected to ensure they are suitable. All supports should
be protected against corrosion.
If noise levels are of particular importance, the heater should
be isolated from the structure of the building by installing it on
suitable anti-vibration mountings.
In all such cases, and in addition, when the heater is suspended
it is essential that all oil, duct, electrical and flue connections
to the heater are made with flexible connections to maintain
continuity of connection. In the case of the flue connection
single wall stainless steel flue is deemed to flex sufficiently to
meet the requirements.

4.3 Connection of Air Heater(s) to Flue
System

The flue system connects directly into the flue socket on the
top (OUH20) or rear (OUH30 - 60) of the heater. The socket is
sized to accept standard sheet metal flue that is secured in place
using suitable fasteners.
The flue system must be fabricated with sockets facing upwards
and sound joints must be achieved by either:
(a) a close tolerance mechanical fit between sections, or
(b) the use of a suitable caulking string and cold caulking
compound.

4.4 Condensate Drainage

The design of the flue system should minimise the formation
of condensation and long external runs should be completed in
twin wall insulated flue. Where condensate and/or rain water
ingress is envisaged to be a problem a flue drain length or
condensate drain tee that drains into a gulley must be fitted.

4.3.2. General Requirements

In all cases the flue outlet socket must be connected via an
approved flue system to outside air. . If an offset is required two
sets of 45° bends may be used each set being equivalent to 0.5m
of flue length. The minimum flue length (end of flue terminal

to top of heater) shall not be less than 2.0m.
All flue ducts must be supported independently of the air heater.

5

The flue 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.

- 2000mm from ground level.

4.3.3 Installation of Flue System

4.4 Oil Connection

The oil pipework length and diameter should be in accordance
with the information given in the burner instruction booklet.
The pump suction should not exceed 0.4 bar.
The oil line must terminate not more than 450mm from the
burner with the final connection by the flexible hoses supplied
with the burner.
Because the burner is firing downward it is recommended that
an additional oil solenoid valve (available as an optional extra)
is fitted adjacent to the burner, and wired as shown in Section
8 (Page 9), to eliminate any possibility of syphoning through
the burner.

4.5 Electrical Connections

All units are fully prewired and only require final connection
of the incoming mains supply and completion of the control
circuit (230V) via a room thermostat, time clock etc.
All units must be earthed. The electrical supply must be run to
a point adjacent to the heater and be suitably terminated to
provide an isolation point that will prevent remote activation
of the unit during servicing. See Table 3 (Page 3) to ascertain
the electrical loading of the unit(s) so that cables of adequate
cross-sectional area are used for the electrical installation. The
length of the conductors between the cord anchorage and the
terminals must be such that the current carrying conductors
become taut before the earth conductor if the cable or cord slips
out of the cord anchorage. All external controls must be of an
approved type.
See the wiring diagram in Section 8 (Page 9).
OUH/D models supplied less fan must be electrically interlocked
to the air movement system so that this is started in the same
manner as the air heater fan would be viz. A connection from
the heater terminal marked “Live Main Fan” must be made to
one side of the fan motor contactor coil, the other side of the
coil being connected to Neutral. The fan motor electrical supply
must be direct and not taken from the internal wiring of the
OUH heater.

6

5. Air Distribution System

f) If a Powrtrol or MC200 is being used that the Winter mode
is selected.

5.1 General

OUH/C and OUH/D models are designed for use with duct work
to more precisely define the point of air delivery, and /or provide
ducted return air or ducted fresh air inlet. All ducting must be
independently supported of the air heater.
Joints and seams of supply ducts and fittings must be securely
fastened and made airtight. If required the ductwork should be
insulated to reduce heat loss.

5.2 Noise Reduction

Ducting should be connected to the heater spigots via an airtight
flexible coupling of non-combustible material. Before fitting
the coupling it must be ensured that a minimum clearance of
approximately 15mm will be maintained between the ends of
the ducting and the heater spigots.
Sound attenuators may be fitted in inlet and outlet ducts to
reduce airborne fan noise. Materials used in outlet sound
attenuators must be capable of withstanding 100°C air
temperature without any deterioration.

5.3 Room Thermostat Siting

The room thermostat should be fitted at a point which will be
generally representative of the heated area as far as temperature
is concerned. Draughty areas, areas subjected to direct heat e.g.
from the sun, and areas where the air movement is relatively
stagnant e.g. in recesses, are all positions to be avoided.
The thermostat should be mounted about 1.5m from the floor.
Any room thermostat, frost thermostat, time clock etc. must be
suitable for switching 230V, 5A and must be of the 'snap action'
type to minimise contact bounce.
For electrical connections of external controls see the wiring
diagram (Page 9).

6. Commissioning & Testing

6.1 Electrical Installation

Checks to ensure electrical safety must be carried out by a
qualified person.

6.2 Oil Installation

This should be commissioned generally in accordance with BS
5410 Part 2 Section 59 Paragraphs 59.1.1.1 to 59.1.1.6

6.3 Air Distribution System

The system should be checked to ensure that the installation
work has been carried out in accordance with the design
requirements.
Particular attention should be given to the correct arrangement
of delivery ducts and registers, return air ducts and grills and
general adequacy of return air paths.
For OUH/C and OUH/D units ensure that the ductwork is
balanced so that the specified motor running currents are
achieved.

6.5 Lighting the Air Heater

Refer also to the burner instruction booklet.

1. Remove the burner cover after releasing the three retaining
screws.

2. Fit pressure gauge, complete with vent tee to oil pump.

3. Check oil supply valve is open.

4. Switch on electricity supply and the burner fan should start
to run. If it does not, check the red lock out button on the control
box. If this is illuminated depress once to re-set.

5. During the pre-purge period bleed the air from the pump and
pipework through the bleed plug on the pressure gauge vent tee,
until air free oil is obtained.
N.B.: Depending upon the length of pipework it may be
necessary to repeat this operation more than once. If this is the
case it should be noted that the burner will go to lockout and
therefore the lock-out button must be pressed to restart the
burner.

6. Once air free oil is flowing from the bleed plug close the
gauge vent plug. If necessary restart the ignition sequence.

6.6 Adjustments

6.6.1 Oil Pressure

Leave the appliance to run for 15 minutes and then cheek that
the oil pressure is as specified in Table 5 Section 2. If not adjust
the pump pressure accordingly. (See burner instruction booklet.)

6.6.2 Combustion

1. Complete a flue gas analysis. The Carbon Dioxide content
should be within ± 0.5% of the following values, if not adjust
combustion air accordingly, (See burner instruction booklet.)
and re-check the flue gas analysis.
OUH 20 12.5%
OUH 30 12.8%
OUH 45 & 60 12.0%

2. Turn the room thermostat to MIN to turn OFF the burner.
Remove the pressure gauge, refit the sealing plug into the pump.

3. Refire the burner and ensure that there are no oil leaks. Replace
the burner cover.

6.7 Handing over the Air Heater

Hand these instructions to the user or purchaser for retention
and instruct in the efficient and safe operation of the air heater
and associated controls.
Adjust the automatic controls to those values required by the
User.
Finally, advise the user or purchaser that, for continued efficient
and safe operation of the air heater, it is important that servicing
is carried out annually.
In the event that the premises are not yet occupied turn off the
oil and electricity supplies and leave instructional literature on
site.

7. Servicing

WARNING: Always switch off and disconnect electricity supply,
close the gas service valve or turn off the oil supply before
carrying out any servicing work or replacement of failed
components. (Refer also to the burner instruction booklet.)

6.4 Checks before lighting the Air Heater

This should generally be in accordance with BS 541 Part 2
Section 59.2.1.1 to 59.2.1.5 inclusive. In addition check that:
a) The ELECTRICAL supply to the heater is switched OFF.
b) That all warm air delivery outlets are open.
c) That the thermostat is set at MAX.
d) That the clock control is set to an ON period.
e) That any other controls are calling for heat.

7.1 General

Full maintenance should be undertaken not less than once per
year. After any servicing work has been complete or any
component replaced the air heater(s) must be fully commissioned
and tested for fuel tightness as described in Section 6.

In addition the following should be completed.
a) Check and clean any oil filters
b) Check the correct operation of any fire valves

7

7.2 Burner Servicing/Maintenance

1. Refer to the burner instruction booklet supplied with the
heater and complete the servicing/maintenance instructions
therein.

nose pliers, before the replacement thermostat is installed.

5. Ensure that the fan and limit settings are as follows:­ Fan ON - 50°C, Fan OFF - 30°C
Limit OUH 20 115°C
OUH 30 - 60 90°C

7.3 Main Burner Assembly Removal

1. Ensure that the oil valve is turned OFF and then disconnect
the oil supply pipe from the burner.

2. Disconnect the electrical connections to the burner.

3. Remove the nuts securing the burner to the heater.

4. reassemble in reverse order.

7.4 Heat Exchanger

Whilst the main burner assembly is removed from the unit check
that the inside of the heat exchanger is clean. If necessary clean
out deposits using a stiff brush and vacuum cleaner.

7.5 Main Fan Assembly

7.5.1 OUH/F Models

1. Inspect the fan blades to see that they are not damaged and
that there is no excessive build up of deposits that could give
rise to an imbalance. Should it be necessary to remove the
assembly for cleaning proceed as follows.

2. Slacken the cable gland on the heater casing through which
the fan electrical cable passes.

3. Disconnect the fan leads from the electrical terminals.

4. Withdraw cable through entry grommet.

5. Remove the fan and motor assembly complete by removing
the four hexagon headed bolts that secure the fan to the rear
panel.

6. Reassemble in reverse order.

Fig 1 Limit Thermostat

Mechanical Limiter

Release Point

C A U T I O N

D O NO T RO TAT E - HO LD

C

°

Fan Circuit

Fan ON

Override

D IA L WH EN S ET TI NG P OI NT ER S

Jumper Location

Note: The new L4064N may be supplied with the limit
temperature mechanically limited to less than the setting
required. To release the mechanical limit push a pointed object
into the small hole at the top of the dial. At the same time prevent
the dial from rotating and push the limit temperature adjuster
around to the required setting.

2

T

O

0

M

I

I

L

F

N

F

O

F

6

4

0

Set Point Dial

0

2

1

N

0

F

A

0

F

1

O

0

8

0

Mechanical limiter

Limit Setpoint
Adjustment

Limit Circuit

Fan ON Setpoint
Adjustment

Fan OFF Setpoint
Adjustment

Limit Reset

Limit CircuitFan Circuit

7.5.2 Centrifugal Fan

1. Inspect the fan blades to see that they are not damaged and
that there is no build up of excessive deposits that could give
rise to an imbalance. Should it be necessary to remove the
assembly for cleaning proceed as follows.

2. Slacken the cable gland on the casing through which the fan
electrical cable passes.

3. Disconnect the fan leads from the electrical terminals in the
contactor enclosure.

4. Withdraw cable through entry grommet.

5. Remove the complete fan assembly by removing the fixings
securing the fan to the rear panel of the heater.

6. Reassemble in reverse order.

7.6 Replacement of Faulty Components

7.6.1 Fan/Limit Thermostat

- Honeywell L4064N

1. Release the single screw securing the fan and limit thermostat
cover and remove cover by pulling upwards.

2. Release wiring from clamp terminals by pushing a small
screwdriver into the clamp release holes adjacent to the clamps.

3. Remove the 2 screws securing the thermostat to the heater
panel and withdraw thermostat.

4. Reassemble new unit in reverse order referring to the heater
wiring diagram to ensure correct wiring location.

Important: A replacement fan/limit thermostat will have a brass
link between the bottom fan terminal and the bottom limit
terminal (situated in the slot between the two terminals). This
MUST be removed, by breaking the link off using a pair of thin

8

8. Wiring Diagram

POWRTROL

MAINS SUPPLY

230v 1ph 50Hz

VENT

VENT

CLOCK

O/P

HEAT

IN

HEAT

OUT

L

N

EARTH

NEUTRAL

LIVE

L N

1 234

RIELLO OIL
BURNER

N L

5

8 9

6

7

10

11

Additional Oil

Valve

CAPACITOR

Blue

Black

Brown

Gr/Yellow

MAIN FAN

White

Brown

Red

LIMIT FAN

°c

Remote

Lock out Indicator

and reset

Blue

9. Short List of Parts

Only originally specified parts may be fitted as service replacements.
Please refer to Powrmatic Ltd for any parts not detailed in the listing below.

ITEM USAGE PART #

Fan & Limit Thermostat - Honeywell L4064N All 143000303

9

BSI Registered Firm

FM 414

Ind. & Comm. Air Heaters;

Air Moving Equipment;
Flues & Chimneys; Natural
Smoke & Heat Ventilators;
Powered Supply & Extract

Fans & Systems.

ISO 9001

HEATING DIVISION

Hort Bridge

Ilminster, Somerset TA19 9PS

Tel: [phone] Fax: [phone]

Every effort is made to ensure accuracy at time of going to press. However as part of our policy of continual product improvement, we reserve the right to alter specifications without prior notice.

10