Laars FT Series - SECTION 7 Trouble Shooting; Diagnostic Questions and Answers

The FT Series Floor Standing, Combination Boiler
Page 77
Question Answer
Burner does not ignite
when the hot water is
opened.
Make sure that the ON/OFF button on the Control Panel has been turned ON.
If the monitor on the Control Panel is blank, make sure the power cord is plugged and 4A
fuses on the main controller in the units are good.
Make sure that there is water supplied to the unit. The unit activates once the inlet water
ow is over 0 gpm.
Make sure the cold and hot water lines are not plumbed in reverse side.
Make sure that the cold water and gas supply lines are opened.
Make sure that the water lines are not frozen.
Water is not hot enough.
Check that the setting temperature on the unit is not too low
Make sure that the lter in the cold water supply line is not clogged with debris.
Make sure that the gas supply type is correct.
Check the supply and manifold gas pressures are in accordance with specications.
Make sure that the water ow sensor with three wires has been properly connected on
the top of heat exchanger.
Water is too hot.
Make sure that the setting temperature on the unit is not too hot.
Make sure that the lter in the cold water supply line is not clogged with debris.
Make sure that the gas supply type is correct.
Hot water temperature
uctuates at the opened
tap.
Make sure that the lter in the cold water supply line is clean.
Make sure that the gas supply type is correct.
Check the supply gas pressure is su󰀩cient.
The blower is still oper-
ating after the combus-
tion stops.
This is normal because the blower keeps operating for 1 minute to vent (exhaust) the
ue gas from the chamber once the combustion has stopped.
Temperature Rise
too Quickly
Occurs when supply water temperature in heat exchanger rises faster than 2°F per
second during the rst two minutes the burner is on. Automatically resets after a
few minute delay or using manual reset on control panel. See message displayed
TEMPERATURE SENSOR and follow procedure for loose connections.
Abnormal sounds come
from unit during opera-
tion.
A leak of combustion gas between sealed chamber and exhaust tube inside the unit.
Call a qualied service technician for evaluation.
Improper venting termination, make sure that the venting termination complies with
specication.
Check the supply gas pressure is su󰀩cient. Insu󰀩cient gas pressure will cause unstable
burner ame and noise.
Heater doesn’t re when
DHW ow is initiated
Potentially the domestic water ow is too low. Min allowable is 0.75 gpm. Check in
Manual Mode OTO AGA
CH Temp drops lower
than expected before unit
re-res
Change Parameter 14:bo to 10 degrees F (5.5 degrees C)
SECTION 7 Trouble Shooting
7.1 Diagnostics