LAARS NeoTherm NTV (Sizes 150–285 MBTU/h) - Service Manual - Manual (Page 12)

2
Service Manual NeoTherm 80 - NeoTherm 285
Unit Will Not Fire - Blower is Not Running
A2
No
Yes
Check 120V AC electrical power.
Display is lit?
See Section B2 -
“Troubleshooting the 24V AC
Power Supply”
No
Check for correct “call for heat” signal.
(5-6 on TB7)
See Section B18
“Checking the Blower”
See Section B15
“Checking the Air
Pressure Switch”
Blower-related
problem?
Disconnect sensor for Outdoor Reset
(if used)
No
System operates
normally?
Yes
See Section B29
“Troubleshooting the Outdoor
Reset System”
(continued)
Yes
Yes
Short contacts:
Central Heat: 5-7 on TB7
DHW: 5-6 on TB6
Original user interface shows:
Check, Pre-Purge, Run = Normal operation
Current user interface shows:
Heat demand or DHW = Normal operation
Has call for heat? No