ITR OASIS SCH33 User manual

International Thermal Research i
Installation and
Operating Manual
Oasis SCH33
Diesel Heating System for
Recreational Vehicles

Table of Contents
ii Installation Manual for Oasis SCH33 Heating System
Manual Issue Date/Copyright © November 2023
International Thermal Research
IN CANADA: IN THE UNITED STATES:
2431 Simpson Road 5305 NE 121st Ave., Suite 401
Richmond, BC, Canada V6X 2R2 Vancouver, WA USA 98682
Tel: [phone] or 604-278-1272 Tel:[phone] or 360-993-
4877
Fax: [phone] Fax: [phone]
Email: [email protected] www.itrheat.com
Website: http://www.itrheat.com All rights
reserved. No part of this manual may be reproduced
or transmitted in any form by any means, electronic
or mechanical, including photocopying and recording,
information storage, retrieval, or transmission,
without permission in writing from International
Thermal Research
Right to Modify:
Due to our commitment for quality and ongoing
product improvement, ITR reserves the right to
modify or change without notice, any materials,
applications, equipment, accessories, and/or prices.
All measurements and weights are approximate.
Read and save these instructions for future reference

Table of Contents
International Thermal Research iii
Table of Contents
Technical Specifications and Standards
Dangers • Warnings • Cautions • Notices
Section 1, Overview .........................................................1-1
1.1 Unpacking the Heating System......................................... 1-2
1.2 Protect Your Warranty .................................................... 1-2
1.3 Heater Features............................................................. 1-3
1.4 Critical Factors .............................................................. 1-5
1.5 Equipment, Tools, and Skills ............................................ 1-5
1.6 Testing and Inspection.................................................... 1-6
Section 2, Mounting the Heater Unit ................................2-1
2.1 Before You Begin ........................................................... 2-1
2.2 Mounting Location.......................................................... 2-2
2.3 What NOT to Do ............................................................ 2-4
2.4 Procedure..................................................................... 2-4
2.5 Remote Operating Panel Mounting Procedure ..................... 2-5
Section 3, Installing the Exhaust System.........................3-1
3.1 Before You Begin ........................................................... 3-1
3.2 Mounting Location.......................................................... 3-2
3.3 What NOT to Do............................................................. 3-4
3.4 Installation Procedure..................................................... 3-4
Section 4, Installing the Fuel System...............................4-1
4.1 Before You Begin ........................................................... 4-1
4.2 Fuel System Installation.................................................. 4-1
4.3 What NOT to Do ............................................................ 4-2
4.4 Procedure..................................................................... 4-3
Section 5, Installing Fan Heaters .....................................5-1
5.1 Before You Begin ........................................................... 5-1
5.2 Fan System Operation .................................................... 5-2
Features....................................................................... 5-2
Multiple-Zone Heating .................................................... 5-2
Accessories and Components Needed................................ 5-3
5.3 What NOT to Do ............................................................ 5-3
5.4 Mounting Locations ........................................................ 5-4
5.5 Procedure..................................................................... 5-4

Table of Contents
iv Installation Manual for Oasis SCH33 Heating System
Section 6, Wiring the Electrical System ........................... 6-1
6.1 Before You Begin ............................................................6-1
6.2 Oasis SCH33 12 VDC.......................................................6-1
6.3 Oasis SCH33 120/240 VAC ..............................................6-2
Procedure .....................................................................6-3
6.4 Electrical Components .....................................................6-3
6.5 What NOT to DO.............................................................6-6
6.6 Procedure......................................................................6-6
Section 7, Plumbing and filling the System...................... 7-1
7.1 Before You Begin ............................................................7-1
7.2 Heat Transfer Fluid (Propylene Glycol) Plumbing
Installation Procedure......................................................7-2
7.3 What NOT to Do .............................................................7-5
7.4 Potable Water Plumbing Installation (optional).....................7-6
7.5 Engine Waste-heat and Engine pre-heat Plumbing
(optional) ......................................................................7-6
7.6 Procedure Filling/Purging the Oasis SCH33 Heating
System .........................................................................7-7
Section 8, Hot Water Heating and Engine Heat Management8-1
8.1 Before You Begin ............................................................8-1
8.2 Domestic Hot Water System .............................................8-2
8.3 Engine Waste Heat Function ............................................8-3
procedure......................................................................8-4
8.4 Engine Pre-Heat Function .................................................8-4
procedure......................................................................8-4
Section 9, Operating the Oasis SCH33 heating System .... 9-1
9.1 Features of the Oasis SCH33 Heating System ......................9-1
9.2 Starting the Heater .........................................................9-3
9.3 Signs of Normal Operation................................................9-3
9.4 Main Control Board Operation ...........................................9-4
9.5 Stopping the Heater (for Seasonal Purpose) ........................9-4
9.6 Using the Electric Heating Elements ...................................9-5
9.7 Activating the Cabin Fans through the Thermostats ..............9-5
9.8 Activating the Domestic Hot Water ....................................9-5
9.9 Domestic Water temperature Adjustment ...........................9-5
9.10 Stopping the Heater (for Maintenance) ..............................9-6
9.11 Resetting a Fault ............................................................9-6
9.12 Electrical noise ...............................................................9-6
9.13 Maitenance ....................................................................9-8
9.14 Protecting the Heating System ..........................................9-9
Section 10, Troubleshooting.......................................... 10-1

Table of Contents
International Thermal Research v
10.1 Overview............................................................. 10-1
10.2 Power On (Green) ................................................. 10-1
10.3 Burner On ........................................................... 10-1
10.4 Service Switch Off................................................. 10-2
10.5 Remote Switch Off ................................................ 10-2
10.6 Heater Cycling (Normal Operation) .......................... 10-2
10.7 Thermostats Off (Normal Operation) ........................ 10-3
10.8 Voltage Low of High .............................................. 10-3
10.9 Overheat ............................................................ 10-4
10.10 Fuse Blown .......................................................... 10-4
10.11 Fuel Pump/Solenoid .............................................. 10-5
10.12 Igniter ................................................................ 10-5
10.13 Combustion Fan ................................................... 10-6
10.14 Water Pump......................................................... 10-6
10.15 Flame Out ........................................................... 10-6
10.16 Compressor ......................................................... 10-8
10.17 Bypass Mode........................................................ 10-8
10.18 Water Pump On (Green) ........................................ 10-8
10-19 Flame Sensor Module ............................................ 10-8
10.20 Test Points........................................................... 10-9
10.21 Reduced Output.................................................. 10-10
10.22 Smokey,Smelly Exhaust ...................................... 10-10
Section 11, Maintenance ................................................11-1
11.1 The First Few Weeks ............................................. 11-1
11.2 Adding Heat Transfer Fluid (Antifreeze) .................... 11-1
11.3 Nozzle................................................................. 11-2
11.4 Fuel Lines and Filter .............................................. 11-2
11.5 Combustion Chamber ........................................... 11-2
11.6 Checking Hoses and Tubes ..................................... 11-2
11.7 Electrical System .................................................. 11-3
11.8 Recommended Spare Parts .................................... 11-3
11.9 Protecting Hydronic Heating Systems ....................... 11-4
Section 12, Warranty and Service ..................................12-1
12.1 General Warranty ................................................. 12-1
12.2 Limited Warranty ................................................. 12-1
12.3 Owner’s Responsibility ........................................... 12-2
12.4 Not Covered Under Warranty .................................. 12-2
12.5 Customer Service Calls ......................................... 12-3
12.6 Returns ............................................................... 12-3
12.7 Telephone /Email Service ....................................... 12-4
12.7 Owners Service Log............................................... 12-4
Inspection Check sheet (including Test Points)
Warranty Information & Warranty Card

Table of Contents
vi Installation Manual for Oasis SCH33 Heating System
List of Figures
Figure 1-1 Oasis SCH33 Heating System.......................................1-1
Figure 1-2 Oasis SCH33 Heating System Overview .........................1-4
Figure 1-3 Oasis SCH33 Typical seiries-Plumbed Layout ..................1-7
Figure 2-1 Oasis SCH33 Dimensions ............................................2-3
Figure 2-2 Heater Mounting Bracket Configuration .........................2-4
Figure 2-3 Basic and Touchscreen Operating Panel Mounting ...........2-5
Figure 3-1 Oasis SCH33 Exhaust parts and Typical Configuration ......3-5
Figure 3-2 Oasis SCH33 Typical Fresh-air intake Config. and
Optional Air Intake Silencers........................................3-5
Figure 5-1 Wiring the Fan’s Aquastat............................................5-2
Figure 5-2 Mounting a Low-Profile Cabin Fan .................................5-5
Figure 5-3 Installing a Relay for Additional Fan Amperage ...............5-5
Figure 6-1 Sample Wiring Diagram for Electrical Elements ...............6-3
Figure 6-2 Wiring for a Fan Speed Switch .....................................6-8
Figure 6-3 Wiring Diagram V2001................................................6-9
Figure 7-1 Oasis SCH33 Overview ...............................................7-3
Figure 7-2 Plumbing SCH33 with optional summer loop for
portable water and engine waste heat/ pre-heat options ..7-4
Figure 7-3 Plumbing SCH33 with portable water and engine waste
heat/ pre-heat options................................................7-4
Figure 7-4 Approved Methods of Installing Heater Hose (consult
ITR for alternative methods and products) .....................7-5
Figure 7-5 Filling/Purging Oasis SCH33 Heating System ..................7-8
Figure 8-1 Single Loop System, three fans, optional summer loop ....8-3
Figure 11-1Maintenance Schedule.............................................. 11-4

International Thermal Research 1-1
Overview
Thank you for purchasing the Oasis®SCH33™diesel hot
water heating system.
This section describes features of the Oasis SCH33 heater and
explains what to do when you first receive your heater. It
also covers critical information you need to know before
beginning the installation, including how to protect your
warranty, and tools and equipment needed.
Figure 1-1: Oasis SCH33 Heating System
Section
1
Some of the figures
in this manual
represent a typical
installation, but
other configurations
or methods may be
acceptable. If in
doubt, contact ITR
for assistance.

Section 1, Overview
1-2 Installation Manual for Oasis®SCH33™Heating System
1.1 Unpacking the Heating System
When you receive your Oasis SCH33 heater:
1
Unpack it carefully.
2
Check each component against the provided parts list to
ensure that you have everything and that all parts are
undamaged.
3
If you discover any missing or defective parts, call ITR
immediately.
4
If you are not installing the heater right away, secure all
components so none will be misplaced.
5
Before installing the heater, read the rest of this
Instruction and Operation Manual. It contains
critical information for a proper installation.
It’s important to follow the installation procedures in this
manual to ensure maximum performance of the heater and
that you and/or your customers enjoy a warm, comfortable
environment and plenty of hot water when needed.
1.2 Protect Your Warranty
This document reflects approved installation techniques,
methods, and materials, and applies only to ITR equipment.
The heater and supplied components are only guaranteed by
ITR if the entire system has been installed according to the
requirements and recommendations set forth in this manual.
Warranty coverage will not be extended to heaters and
system components (supplied by ITR) used in an improper
installation. Use of any unapproved materials, equipment, or
installation procedures will void the warranty for the entire
heating system. ITR does not accept liability for any damage
or loss of service resulting from unapproved installations
and/or modifications.
NOTICE

Section 1, Overview
International Thermal Research 1-3
1.3 Heater Features
The Oasis SCH33 is an advanced and efficient hydronic heater
with many advantages over older technology of forced-air
systems. The SCH33 provides space heating using a “heat-
transfer fluid” pumped to remote mounted, fan equipped,
radiator-style heat-exchangers. The same “hot”fluid can be
circulated through an optional highly efficient, externally
mounted, flat-plate heat-exchanger to provide a continuous
supply of domestic hot water through a mixing valve. The
heater runs on 12VDC power, using a diesel-fired burner to
maintain the temperature of the heat transfer fluid. The
Oasis SCH33 heater can also use waste heat from the
engine, using an optional external heat exchanger. The
addition of an optional secondary water pump will also allow
pre-heating of the engine.
Other features of the heating system include:
•1500 Watt, 120 VAC (North America) electric element for
a supplemental and backup heating source when the vehicle
is connected to a power source
•High-temperature stainless steel burner and water jacket
to prevent premature warping or burnout
•Internal circulation pump for heating loop and hot water
heat exchanger
•Insulated enclosure retains heat and minimizes noise
•Easy to install, field serviceable, with hookups and
connections easily accessible from the top of the heater
•Quiet operation and low power consumption
•Low-pressure fuel system with built-in fuel pump
•Fuel-efficient burner capable of burning a wide variety of
diesel-based fuels
•No smoke or smell from the exhaust
•Fan assisted; sealed combustion chamber is designed to
use outside air through a direct ventilation hook-up
•Simple, low amperage draw ignition
Return fuel line to eliminate air and prevent nuisance
shutdowns
Oasis SCH33
ADVANTAGES
•Efficient
•Clean
•Quiet
•Compact
•Safe
•Rugged
•Reliable
•Economical

Section 1, Overview
1-4 Installation Manual for Oasis®SCH33™Heating System
Electronically-controlled system with:
oAutomatic safety shutdown
oManual reset overheat temperature sensor and a
thermal cutoff for overheat protection
oBasic or Touch screen control panel for operating
control and diagnostics with audible alarm
•Heating control for up to four separate space heating
zones, each with its own optional thermostat
•Optional on demand, continuous domestic water heating
without the need for hot water storage (using an external
heat exchanger and mixing valve)
•Optional use of engine waste heat to provide system
heating (using an external heat exchanger)
•Engine heating (using an optional external heat
exchanger and pump)
Figure 1-2: Oasis SCH33 Heating System Overview