LAARS HEATING SYSTEMS
Page 2
TABLE OF CONTENTS
SECTION 1.
General Information
1A.
Introduction .................................................... 3
1B.
Warranty ........................................................ 3
1C.
Technical Assistance ..................................... 3
SECTION 2.
Installation Instructions
2A.
General Information ....................................... 4
2B.
Field Assembly .............................................. 4
2C.
Site Location .................................................. 5
2C-1.
Installation Information .................................. 5
2C-2.
Outdoor Installation (U.S. only) ..................... 5
2C-3.
Flooring - Typical Installation ......................... 6
2D.
Combustion and Ventilation Air Supply ......... 6
2D-1.
Outdoor Air Supply ........................................ 7
2D-2.
Indoor Air Supply ........................................... 7
2D-3.
Exhaust Fans or Vents .................................. 7
2E.
Venting of Combustion Products ................... 7
2E-1.
General Information ....................................... 7
2E-2.
Replacement of Existing Heater .................... 8
2F.
Water Flow .................................................... 8
2F-1.
Reversible Water Connections ...................... 8
2F-2.
Water Chemistry .......................................... 11
2F-3.
Freeze Protection ........................................ 11
2F-4
Water Hardness .......................................... 11
2F-5.
Pump Requirements .................................... 11
2F-6.
Pressure Buildup in Water System .............. 11
2F-7.
Pressure Relief Valve .................................. 14
2F-8.
Water Pressure ........................................... 14
2F-9.
Pump Installation ......................................... 14
2F-10. Storage Tank Installation ............................. 14
2F-11. Thermal Circulation of Hot Water in
Cold Water Supply Lines ............................. 15
2G.
Gas Supply and Piping ................................ 15
2G-1.
General Instructions .................................... 15
2G-2.
Special Precautions for Propane Gas ......... 16
2H.
Electrical Wiring ........................................... 16
2I.
Combined Space Heating/Potable
Water Heating Systems ............................... 16
2I-1.
Combined Space Heating ........................... 16
2I-2.
Potable Water Heating ................................ 16
SECTION 3.
Operating Instructions
3A.
Normal Operating Sequence ....................... 17
3B.
Start-Up Procedure ..................................... 17
3C.
Setting the Temperature Controls ............... 17
3D.
Adjustment for Minimum Input Rate
(models with modulating gas valve) ............ 20
3E.
Hi-Limit Switch Checkout ............................ 20
3F.
Shut-Down Procedure ................................. 20
SECTION 4.
Maintenance
4A.
General Instructions .................................... 20
4B.
Replacement of Gas Controls ..................... 21
4C.
Heat Exchanger ........................................... 22
4C-1.
Inspecting the Heat Exchanger ................... 22
4C-2.
Cleaning the Heat Exchanger ..................... 23
SECTION 5.
Troubleshooting
5A.
Gas Pressure Tests ..................................... 23
5A-1.
Checking the Main Line Gas Pressure ........ 23
5A-2.
Checking the Manifold
Regulated Gas Pressure ............................. 24
5B.
Electrical Troubleshooting ........................... 24
5B-1.
Heater Does Not Come On ......................... 24
5B-2.
Testing the Transformer .............................. 25
5B-3.
Testing the Electrical Power Supply ............ 25
5B-4.
Testing the Manual Reset
Hi-Limit Switch ............................................. 25
5B-5.
Testing the Flow Switch ............................... 25
5B-6.
Testing the Fusible Link
(Flame roll-out switch) ................................. 26
5B-7.
Testing the Fuse .......................................... 26
5B-8.
Testing the Ignition Control
(for spark ignition) ........................................ 26
5B-9.
Testing the Ignition Control
(for standing pilot) ........................................ 27
5B-10. Testing the High Voltage Ignition Lead ........ 27
5B-11. Testing the Safety Shutoff
(for standing pilot) ........................................ 28
5B-12. Testing the Safety Shutoff
(for automatic pilot) ...................................... 28
5B-13. Testing the Igniter Electrode ........................ 28
5B-14. Testing the Pilot Thermocouple
(for standing pilot) ........................................ 28
5B-15. Testing for Pilot burner
(for spark ignition) ........................................ 28
5B-16. Testing for Burner Ignition
(for standing pilot) ........................................ 29
5B-17. Heater Will Not Shut Off .............................. 29
5B-18. On-Off Main Burner Cycling ........................ 29
5B-19. Testing the Terminal Strip/External
Controls ....................................................... 29
SECTION 6.
Parts List
6A.
General Information ..................................... 30
6B.
Parts List ..................................................... 30
