2
Hazard definitions
The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or
to important information concerning the life of the product.
⚠
DANGER
⚠
WARNING
⚠
CAUTION
CAUTION
NOTICE
DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious
injury.
WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious
injury.
CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate
injury.
CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not
avoided, may result in property damage.
NOTICE indicates special instructions on installation, operation, or maintenance that are important but not
related to personal injury or property damage.
HAZARD DEFINITIONS
.................................................. 2
PLEASE READ BEFORE PROCEEDING
..................... 3
THE APW -- HOW IT WORKS
........................................ 4
1. DETERMINE APW LOCATION
Before locating the appliance, check: ................................ 5
Site selection and preparation ........................................... 5
Installation clearances ....................................................... 5
• APW Water Heater Clearances ................................. 6
2. PREPARE WATER HEATER
Receiving and unpacking the APW .................................... 7
Setting the unit ................................................................... 7
3. HYDRONIC PIPING
APW piping assemblies ..................................................... 8
General piping information ................................................. 8
Heating fluid and Domestic Hot Water (DHW) piping ........ 8
Scalding ............................................................................... 8
Hydronic piping illustrations ......................................... 9-14
4. ADJUSTMENTS
3-Way control valve adjustment ....................................... 15
• Control valve calibration and status indications .. 15-16
• Manual control of 3-way valve............................. 16-17
Temperature Controller Operating Controls ..................... 18
5. OPERATING INFORMATION
Sequence of operation ..................................................... 19
Electronic control overview .............................................. 19
Over-temperature control and safety features ................. 19
6. WIRING
Electrical wiring connections ............................................ 20
7. MODBUS
Installation procedure ....................................................... 21
ModBus eException Codes .............................................. 22
Primary Data Tables ........................................................ 23
Memory Map .................................................................... 23
Physical Wiring ................................................................. 23
Procedure to change ModBus address ............................ 24
Troubleshooting ................................................................ 24
8. START-UP
Introduction ....................................................................... 25
Pre-operational checks and procedures .......................... 25
Initial start-up .................................................................... 25
Checking mixed inlet temperature ................................... 26
Shutting down the system ................................................ 26
9. MAINTENANCE
Maintenance and annual startup ...................................... 27
Periodic cleaning of heat exchanger ................................ 28
Strainers - inspection and replacement ........................... 28
Oiled bearing circulators .................................................. 28
Check water heater relief valve ........................................ 28
10. TROUBLESHOOTING
• Table 10A - Troubleshooting Chart - No Display ..... 29
Checking temperature sensors ........................................ 30
• Table 10B - Resistance vs. Temperature ................ 30
11. SIZING DATA
How to properly size your Indirect Water Heater .........31-38
12. DIAGRAMS
Wiring Diagram ............................................................... 39
13. REPLACEMENT PARTS LIST
When ordering replacement parts ..................................... 40
Revision Notes .................................................. Back Cover
Contents
