PHP 25AG User manual

®
Technical Description
Installation Instructions
Operating Instructions
Troubleshooting
25AG AIR HEATER

Table of Contents
Introduction 4
Heater Warnings 5
Specications 6
Heater Kit List 7
Main Components and Operating Concepts 9
Heater Mounting 10
Fuel System 13
Electrical Connections 18
Operating Switch Instructions 20
Exhaust & Combustion Air Intake Connections 29
Heater Ducting 31
Heater Operation 33
Maintenance 35
Troubleshooting 36
Fault Code Chart 38
Heater Components 40

4
Thank you for purchasing our 25AG heater.
The 25AG heater is designed to provide cabin heating for trucks, o-highway equipment and
RVs by using on-board gasoline fuel and battery systems. Operation is simple and the heater
provides a safe and reliable alternative to engine idling or need for electrical plugins.
Please take a moment to familiarize yourself with this manual, safety warnings and heater
requirements before installing or operating your heater.
Introduction

5
Heater Warnings
Special Notes
Warning
Caution
Caution - Operational Considerations
Indicates that personal injury or damage to equipment may occur unless specic guidelines
are followed.
Indicates that serious or fatal injury may result if specic guidelines are not followed.
• The installation of this kit requires trained decision making
concerning locating and integrating components, tying
components together, rerouting, or relocating OEM
components, etc. It is impossible to describe all of the
safety and operational considerations in the installation
instructions, therefore, the technician must exercise
professional judgment to achieve a safe and quality
installation.
• Read and understand this manual before attempting to
install the heater.
• Failure to follow all these instructions could cause serious
or fatal injury. • Exhaust pipe will become very hot during heater
operation.
• Avoid touching exhaust pipe during operation.
• Route exhaust pipe in a manner to shield it from anyone
making contact with it.
This heater is designed to operate continuously at altitudes
from 0 to 3,000 m (10,000’)
Operating in altitudes above this may plug the heater with
soot and result in combustion failure.
• Heater must be turned o while re-fueling.
• Do not install heater in enclosed areas where combustible
fumes may be present.
• Exhaust pipe must maintain a minimum a distance of
50mm (2”) from any ammable or heat sensitive material.
• Ensure there are no leaks in the fuel system.
• Ensure that exhaust fumes cannot enter passenger
compartments.
• The heat exchanger should not be used for more than 5
years. After expiration, it must be replaced with genuine
parts and replaced by the heater manufacturer.
Warning - Installation Hazards
Warning - Burn Hazards
High Altitudes
Warning - Explosion Hazards
Warning - Fire Hazards
Warning - Asphyxiation Hazards
Note: Highlight areas requiring special attention or clarication.

6
Specications
Principal Dimensions
Performance Specifications
Heating Mode High Range Low Range
Heating Capacity kW/hr (BTUs/hr) 2.0 (5,800) 1.0 (2,900)
Fuel Consumption L/hr (US Gal/hr) 0.27 (0.07) 0.14 (0.04)
Air Flow M^3/min (CFM) 1.19 (42) 0.47 (16)
Power Consumption - watts 29 14
Power Consumption at Start - watts ≤ 100
Fuel Type Gasoline
Operating Altitude 0 to 3,000 m (10,000’)
Nominal Voltage 12 Volt
Lower Voltage Limit 10 Volts over 20 seconds
Upper Voltage Limit 15.0 Volt over 20 seconds
Overheat Protection 115º C (239º F)
Allowed Ambient Temperature -40º C to 50º C (-40º F to 122º F)
Weight 2.6 kg (5.7 lbs)
Overall Dimensions Length: 323 mm (12.7”)
Width: 120 mm (4.7”)
Height: 121 mm (4.7”)
Above Specications (± 10%)
323 mm 120 mm
121 mm
29 mm
60 mm
22 mm
22 mm
60 mm
120 mm

7
Heater Kit List
QTY
1
QTY
1
QTY
1
QTY
1
1
QTY
1
1
4
1
QTY
1
Part Number
P65A-X388
Part Number
U65A-X702
Part Number
P65A-X304
P65D-X303
Part Number
U65D-X519
U65D-X522
Part Number
U20A-X603
U20A-X602
U20A-X601
U20A-X604
Part Number
P25A-T888
Description
Operating Switch
Description
Heater Mounting Plate & Seal
Description
Wiring Harness
4.5M (15’) Power Harness, 20A Fuse
6M (20’) Switch Harness
4.5M (15’) Fuel Pump Harness
Description
22mm Flexible Stainless Steel Exhaust,
with End Cap
22mm Combustion Air Intake Tube,1M
with End Cap
Description
60mm Hot Air Ducting 1M (3’) Length
60mm Air Outlet with Adjustable Vent
60mm Air Inlet
60mm Hose Clamps
Description
2 kW Air Heater

8
Heater Kit List
QTY
1
1
1
6
1
12
1
10
1
2
Part Number
P25A-T410
U65D-X407
U65D-X414
U65D-X409
U65D-X403
U65D-X401
U65D-X402
U65D-X705
NPN
NPN
Description
Fuel Metering Pump
Fuel Pump Holder
Black Rubber Fuel Line, 4.5mm ID x 0.5M
4.5mm ID x 50mm Fuel Line Connectors
Clear Nylon Fuel Line, 8M (26’),1.5 - 2.0 mm ID
Small Fuel Line Clamps, 9-11 mm x 9mm wide
Fuel Filter
Cable Ties, Medium Grade, Black, 20cm
Plastic Tee
Large Fuel Line Clamps, 12-14 mm x 9mm
QTY
1
2
1
2
1
7
6
10
10
8
Part Number
U65D-X505
U65D-X712
U65D-X707
U65D-X706
U65D-X702
NPN
NPN
NPN
NPN
NPN
Description
Exhaust Clamp, 24 – 26 mm
25mm “P” Routing Clamp
“Z” Mounting Bracket (See Specs and Drawing)
“L” Brackets (See Specs and Drawing)
Combustion Air Tube Clamp
TEKS Mounting Screws ¼” -14 x 1 1/2”
M6-1 x 25 Hex Head Screw, Grade 8 Zinc Plated
M6-1 Hex Nuts – Grade 8, Zinc Plated
6mm Wave Washers
#8 x 20mm, Self Drilling, Phillips Head Cap

9
Main Components and Operating Concept
• The fuel pump delivers fuel to the combustion chamber.
• The combustion air blower delivers air to the combustion chamber.
• A glow pin is used to ignite the fuel-air mixture.
• The heat from the ame is transferred through the heat exchanger while the exhaust
gases are expelled to the exterior of the vehicle.
• The process air blower transfers air from the cabin, over the outside of the heat
exchanger and blows hot air into the cabin.
• The heater automatically maintains the desired set temperature in the cabin by
regulating through multiple heat output modes.
1) Process Air Blower 6) Blower Motor C. Combustion Air
2) Control Unit 7) Glow Pin E. Exhaust Gas
3) Combustion Air Blower 8) Fuel Metering Pump F. Fresh Air Intake
4) Combustion Chamber & Heat Exchanger 9) Operating Switch H. Hot Air Outlet
5) Overheat Sensor D. Fuel Intake
Main Components
Operating Concept

10
Heater Mounting
Typically, air heaters are mounted inside a tool compartment with the OEM HVAC System.
However, the heater may be mounted anywhere inside the cabin provided you adhere to the
following conditions:
• Combustion air intake, exhaust and fuel inlet connections must be on outside of the
vehicle.
• Heater must be mounted on at surface and provide an air tight seal between heater
and vehicle.
• Heater must be mounted on a at horizontal surface with exhaust port pointed straight
down. (Figure M1)
Heater Location
Figure M1

11
Heater Mounting
• A mounting plate and hardware are provided with the truck heater kit.
• Refer to Figures M2 & M3 for assembly orientation. Note: If the mounting plate will not
be used, the heater ange can be used as a template to mark where the individual
components openings should be made.
• For ease of installation fasten the mounting plate to the heater and make exhaust,
combustion air intake and fuel connections at the base of the heater before mounting
the assembly to the vehicle.
• Cut a two 3”holes or a 4”x 5”rectangular opening on the cabin oor to accommodate
mounting plate and seal. Refer to Figure M4.
• Secure mounting plate to vehicle with self taping“Tek” screws provided.
Mounting
Figure M2
Flat Washer
Nut Spring Washer Cab Floor
Head Tek Screw Silicon gasket (ange)
Stainless Steel Plate
Plate Steel

12
Heater Mounting
Figure M3
Figure M4
2 1/8”
Ø3” x 2
4” x 5”
Rectangle
++

13
Fuel System
The 25AG fuel pump and fuel system are the heart of the heater. The fuel pump not only delivers fuel to
the heater but also controls the amount of fuel delivered. The pump is designed to operate like an electric
solenoid and works using electric pulses. Each time it is energized, it provides a measured dose of fuel.
It is critical to the heater’s operation to stay within parameters outlined in Figure F1 and only use the
components provided.
System Layout & Considerations
• Keep the length of the fuel system short as possible.
• Mount the fuel pump as close to the fuel pickup as possible (pump pushes better than it sucks).
• Minimize vertical rise.
• Mount the fuel pump in a protected location away from road spray.
• Choose a mounting location for the fuel pickup pipe that is close to the heater and oer installation
access.
• Design your fuel system so that Figure F1 fuel line limits are not exceeded.
Figure F1
1. Heater
2. Fuel Pickup Pipe
3. Fuel Metering Pump
4. Fuel Tank
5. 9-11 mm Clamp
6. 4.5 mm Rubber Fuel Line
7. 4.5 mm Rubber Connector
8. 1.5 mm Clear Plastic Fuel Line
2
4
56
Max. 1M (6, 6”)
Max. 2M (12’)
3
8
7
Max. ½ M (18”)
Max. 6M (20’)
Fuel System Overview

14
Fuel System
Connecting the Fuel System
Fuel systems in gasoline vehicles are sealed and electronically monitored to contain fuel vapors.
When integrating the heater, you must ensure that you do not disrupt the integrity of the fuel system.
Installation should only be completed by a competent technician familiar with the fuel system of the vehicle.
Due to the innite variations of fuel systems used in Gasoline powered vehicles, it is impossible to provide
a standard fuel pickup device or procedure that works for every application. The following section outlines
several methods for accessing fuel for your heater. Ensure that your fuel system ts within the specications
outlined in the Fuel System Specication chart Figure 1.
Note:
In some applications, you will be required to drop the tank to be able to access the fuel system.
Parking Heater Products oers two sizes of Mini Pickup Pipes.
These can be adapted to t inside fuel sender plates of the vehicle and create an air tight seal.
Find a suitable place on the fuel sender plate where the tube can be extended into the tank without
interfering with the operation of the fuel sender.
Drill a 5/16” (8 mm) hole and clean o any burrs.
Install either the short or long pickup tube into position and attached the heater fuel line.
Note: Attach a rubber fuel line using a fuel line clamp to the short Mini Pickup to extend into the tank.
U65D-X417 – Short Mini Fuel pickup – 38 mm (1.5”)
U65D-X418 – Long Mini Fuel pickup – 480 mm (19”)
Caution
Mini Fuel Pickup Method:

15
Fuel System
Auxiliary Fuel Port Method
Tee Into Fuel Line Method (NOT RECOMMENDED)
In some instances, the vehicle may have an auxiliary fuel port.
It is possible to use this as fuel tank access.
Consult the vehicle dealer for appropriate connections to adapt to our 4.5 mm rubber fuel line.
Parking Heater Products recommends against Teeing into the vehicles fuel line.
This is because it can be expected that this will interfere with the integrity of the vehicles EVAP System.
This will result in engine error codes and loss of engine performance.
It is possible to Tee into an existing fuel line of other auxiliary equipment such as engine heaters to provide
fuel access for your heater. However, this should be done with caution to ensure there is no disturbance to
the vehicle’s fuel system operation. It is also crucial that the pressure and suction head limitations for the
heater are being observed.

16
Fuel System
Auxiliary Fuel Tank Method
Standard Fuel Pickup Method (Metal tank only)
Auxiliary fuel tanks can be used in some cases as a solution for dicult to access fuel tanks.
However, these are not certied for on-road use.
Standard fuel pickup pipes can be installed in larger metal tanks only.
These can be installed using existing NPT ports in the tanks for by drilling an access hole in the tanks.
Consult Parking Heater Products for further information about this option.

17
Fuel System
Fuel Filter
• An optional fuel lter is provided with your installation kit.
• If used, it should be replaced every two years.
• Mount between the fuel pump and tank.
• Mount on an incline to allow air to pass through.
• Mount with the arrow on the lter pointed towards the fuel pump.
Figure F2
Fuel Pump Mounting
• Using the bracket and rubber mount provided, install fuel pump as shown in Figure F2.
• Isolating the pump with the rubber holder helps to minimize noise created during operation.
• Ensure that the proper mounting angle is observed to avoid cavitation. (Figure F3)
Figure F4
15° to 90°
Figure F3
15° to 90°

18
Electrical Connections
Electrical System Installation
The heater harness has all the electrical connections preassembled for easy installation.
Route cables using either an existing cable passage or drill holes as required.
Seal the hole around the cables and make sure they are protected from chang and pinching.
Below is a summary of the wiring connections required.
Main Harness Combines switch and power harness.
Connects to the heater’s main connector.
Power Harness 2 Core, 4M (13’) Long
Red (+), Brown (-)
Route power harness section from heater to vehicle batteries.
Connect red wire to battery (+)
Connect brown wire to battery (-)
Install 20 amp main fuse (Last step of installation)
Switch Harness 4 Core, 4M (13’) Long
Yellow, Brown, Red, Blue/White
Route switch harness section from heater to switch location.
Connect to operating switch harness
There are also two jumper harness’for remote operation.
One located near the heater and one located at the switch.
Fuel Pump Harness 2 Core, 0.5M (20”) Long
Black, Black
Fuel pump harness exits heater through air intake port.
It then connects to the Fuel Pump Extension Harness
Fuel Pump
Extension Harness
2 Core, 6.5M (21’) Long
Brown, Blue
Route fuel pump extension harness from here and connect
to fuel pump.
External Temperature
Sensor
2 Core Jumper
Brown, Blue
For optional external sensor.
Fuel Pump
Figure E1
Battery
Heater
Fuel Pump
Fuel Pump Harness
20 amp Fuse
Operating Switch
Sw. Jumper
Sw. Jumper Main Connector
External
Temp Sensor
Figure E1

19
Electrical Connections
The following represents the wiring connector locations for the ECU.
The connectors are constructed to ensure that it is impossible to connect in error.
25AG Wiring Diagram
ECU Interfaces
Socket X1 Fan Motor
Socket X2 Glow Pin
Socket X3 Overheat Sensor
Socket X4 Fuel Pump
Socket X6 Main Connector
Figure E2
Figure E3

20
Operating Switch Instructions
The 25AG is provided with a multi-functional operating switch. It is capable of manual and timer controlled
switching of the heater and conveys heater operational parameters and diagnostics.
Mount the operating switch in a suitable location using panel mount method shown in Figure S1
Route the switch harness from the heater to the Operating Switch and connect.
Overview
The operating switch allows you to turn the heater on and o, regulate temperature, set operating mode,
timed shutdown and timed start-up functions. It also facilitates troubleshooting by providing diagnostic
codes.
Drill holes as shown to panel mount switch
Wire Access Hole
11 mm (7/16”)
15 mm (0.6”)
Pinch Mount Hole
8mm (5/16”)
Figure S1