Laars NeoTherm NTH Installation And Operation Instructions Manual - page 36
LAARS Heating Systems
Page 36
49
Maximum cycle count
Control operates correctly,
was reached
however the cycle count will
not increment any higher
than 999,999 cycles
Replace controller or adjust the count using blue display
50
Maximum hours count
Control operates correctly,
was reached
however the hours count will
not increment any higher
than 999,999 hours
248
CH outdoor temperature
was invalid
251
CH ODR max outdoor temp-
Confirm outdoor reset
erature setpoint was invalid
settings. An invalid
252
CH ODR min outdoor temp-
adjustment has been
erature setpoint was invalid
made
253
CH ODR min water temp-
erature setpoint was invalid
254
CH ODR temperature range
Increase Outdoor air temp-
Adjust setting to within appropriate range
was too small
erature min and max values
(min. 12°C / 22°F)
to a difference greater than
22°F (12°C)
255
CH setpoint minus ODR
Increase Outdoor water
min water temperature was
temperature min and max
too small (min. 12°C / 22°F)
values to a difference greater
Increase setpoint or
than 22°F (12°C)
decrease min water temp.
565
Heat exchanger T-rise limit
Heat exchanger temperature
Check for correct water flow
was exceeded
rise exceed
MISCELLANEOUS
Boiler will not stay lit
Indicates lack of flame signal, Check flame detector wiring; clean / replace flame
check fault code on display
detector
Boiler bangs, knocks, hisses
Insufficient water flow /
Check for proper flow, follow piping guidelines in
pump failure; improper piping
manual; replace pump; improper glycol percentage
(see Section 4.3)
Flame pulsates, venting
Insufficient / improper
Ensure venting complies with
Section 2
noise or has difficulty lighting
venting; dirty burner; air in
gas line; dirty heat exchanger
Table 14. Error Codes.
CODE# PROBLEM
PROBABLE CAUSE
SOLUTION
ALERT CODES
temperature controller settings and readings.
5.
When the call for heat is complete, or the unit reaches
its setpoint temperature, the gas valve will close, and
the fan will continue to run for its 20 second post-
purge. If a pump delay time is used, the pump will
continue to run for the specified amount of time
(adjustable from 0.1 to 10 minutes).
8.2 Short Cycling
Because NeoTherm is a modulating boiler, and its
input will decrease when there is a reduction in heating
load, short cycling is greatly reduced. If the heating load
drops below the minimum input of the boiler for an
extended period, the boiler will have a tendency to short
cycle. This can be a symptom of improper control
strategy or setpoints, or a load distribution problem.
NeoTherm has a built-in anti-short cycle (ASC) feature.
ASC is a timed setting that will delay the boiler start for
a specified time after one call for heat is completed.
ASC time may be adjusted as desired (see
Sections
5.2.2
and
5.2.2.6
for more information).
8.3 Error Codes -
See
Table 14
.
SECTION 9.
Replacement Parts
Use only genuine LAARS replacement parts.
9.1 General Information
To order or purchase parts for the LAARS
NeoTherm, contact your nearest LAARS dealer or
distributor. If they cannot supply you with what you
need, contact Customer Service (see back cover for
address, telephone and fax numbers).