Laars NeoThem NTH, Service Manual

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5
Service Manual - NeoTherm 500
Control Unit is in “Standby” Mode
In certain situations, the controller on this unit can go into “Standby”
mode. The Boiler pump is running, so the unit sees a “Call for heat.”
There is no lockout or hold, but something is preventing it from going to
“Run” mode.
A4
No
Check for:
- Call for heat?
- System is up to set-point temp. - no need
for more heat?
- If warm weather shutdown is enabled:
Outdoor air temperature too warm?
Normal
operating
condition?
In certain situations, the controller on this unit can go into
“Standby” mode. The Boiler pump is running, so the unit sees a
“Call for heat.” There is no lockout or hold, but something is
preventing it from going to “Run” mode.
No
Unit operates
normally?
Disconnect outdoor temp. sensor
Yes See Section B33
“Troubleshooting Outdoor Reset”
No
Unit operates
normally?
Set Anti-Short-Cycle to minimum value (white display = 0, current display = 1 min.)
Yes Correct settings for Anti-Short-Cycle
(continued)
Yes