Laars NEOTHERM NTV, Service Manual

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9
Service Manual - NeoTherm 500
Control Unit Says “Run,” But Boiler is Not Firing
In this condition, the panel is lighted, so you know the unit has power.
The Boiler pump is running, so you know the unit is receiving the call
for heat. The blower is running, the unit has spark, and the gas valve is
operating correctly.
Open Safety Chain - Fault #63
This fault indication can point to several different problems:
• Blocked condensate drain
* Blocked exhaust vent
• High or low gas pressure
• Low water in system
• Problem with circulator pump
Fault #63 is a bit like the “Check Engine” light in a car - it indicates a problem, but
does not identify the problem. To identify the specific problem, see Section B3 -
“Checking the Safety Interlocks.”
A7
A8
No
Example:
Stack temp. limit trips,
automatically resets after 20 minutes.
Until this happens, the display says
“Run” but the unit will not fire.
Unit is operating
correctly - recovering
from a trouble
condition?
No
Check safety
interlocks
(Sect. B3)
OK?
Replace the SOLA controller
See Section D8, D9