9.0
Troubleshooting – spark ignition system
Caution:
Condensation can occur in the heat exchanger if boiler is
operated for long periods of time with return water
temperatures less than 120°F (49°C). Significant flue gas
condensation in the boiler will cause corrosion and premature
failure. This type of failure is not covered under warranty.
For boilers connected to large water content systems, such as
a previous gravity system with large free-standing radiators, a
bypass line from supply pipe to the return pipe can be used. A
minimum return water temperature of 120°F (49°C) can be
achieved by diverting some of the flow of heated supply water
into the flow of return water to the boiler. Valves suitable for
balancing, such as globe valves, shall be used and a
thermometer installed in the return line.
In order to assume minimum boiler water temperature
protection, the respective space heating pump must be
connected and controlled by the boiler control (refer to the
corresponding Vitotronic boiler control manual). Pumps
exceeding a rating of 120V/3A need a separate field supplied
motor starter/contactor.
For boilers connected to underfloor heating systems utilizing
plastic tubing with an oxygen diffusion barrier, a 4-way mixing
valve with external control or other suitable alternative must be
installed to prevent condensation and keep boiler return water
a minimum of 120°F (49°C).
Technical sales representative can be contacted to help
resolve doubts and technical questions regarding boiler
installation.
TROUBLE
CAUSE
REMEDY
Pilot burner will
No call for heat
Check that contacts on thermostat
not light
or operating control are closed.
Boiler temperature
Allow boiler to cool and ensure
too high
that limit controls are reset.
No power
Check for 120 VAC power to transformer.
Check for 24 VAC power from transformer
secondary side.
Boiler not switched on
Switch boiler “on” from control panel.
Low water cut-off
Check that boiler and system are
switch open (if equipped)
filled with water.
Pilot fails to light;
Pilot gas valve not
Check wiring to pilot valve. Replace
boiler locks out
opening
gas valve if necessary.
No gas
Check that all valves are open.
Bleed air from line if necessary.
Check orifice in pilot burner for
blockage.
No spark
Check electrode gap of igniter.
Check connections on high tension
cable to igniter.
Ignition module faulty. Replace.
Pilot lights
Poor ionization
Check condition of ionization
briefly, then locks
electrode and electrode gap. Repair
out
or replace. Check pilot gas pressure.
Poor ground
Check all ground connections back
to main power panel.
Main burners fail
Gas valve fails to
Check wiring to main gas valve.
to light
open
Replace main gas valve.
Faulty ignition control module
Replace ignition control module.
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