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17
NO SPARK AT THE PILOT
1. ON/Off switch is not “On” (Position I).
The On/Off switch is located behind the flipdown cover
plate on the front panel strip. See fig. 10.
2. Water flow is not sufficient to activate heater.
Water flow rate at faucet is below minimum flow needed to
activate heater. When temperature adjustment knob is turned
all the way clockwise, the Bosch WR430-3K requires 1/2
gallon per minute flow to activate the heater. As a reference,
this is a flow which would fill a quart jar in 30 seonds. If the
temperature adjustment knob is turned fully
counterclockwise, a flow rate of 1.1 gallons/minute is required
to activate the heater.
3. Water inlet filter is clogged
Water flow is restricted, preventing needed flow to activate
heater. Clean water inlet filter screen.
4. Cross over in water lines
To confirm there is no cross-over in the plumbing, shut off
the cold water supply to the Bosch water heater and open a
not water faucet. There should not be any water flowing at
that faucet. Water running is a sign of a plumbing cross
over. Consult your plumber.
5. Microswitch needs to be adjusted or replaced.
If you do not hear a click when a tap is opened, the
microswitch needs to be adjusted. See Fig 15 for adjustment.
Replace the microswitch if the adjustment does not solve
the problem.
Fig. 15 - Microswitch Adjustment
7. Cold incoming water connection made to wrong side
of heater
Make sure cold water inlet connection is on the right side of
heater when you are facing heater.
8. Water valve parts may be dirty of components damaged
First check that venturi is free of dirt particles. Water valve
and component parts must be totally free of dirt. In hard
water areas, mineral deposits can eventually (3-5 years in
hard water areas) corrode the water valve parts to a point
where they will need replacing. Any sign of moisture at the
top of the water valve is a sign that the water valve needs to
be serviced immediately.
9. Loose connection at the ECO
Ignition sparker will not operate if the electrical circuit is
interrupted. Check that the connections to the ECO are
secure and tighten if necessary.
SPARKS APPEAR AT PILOT WHEN HOT WATER
TAP TURNED ON, BUT PILOT AND BURNERS
WILL NOT IGNITE
1. Air in the Gas Line
Normally this is a problem at time of initial installation, after
the pipes have been worked on, or after a gas supply line
has been allowed to empty. Bleed the air trapped in the gas
line by turning the hot water faucet on and off until the air
has been cleared from the line.
2. No gas to the Bosch
A. Gas cock on gas line may not be open
B. Gas regulator may be shut or damaged. Replace or unjam
the regulator. Note: The regulator furnished with the heater
is exclusively designed for low gas pressure. Excessive
pressure will lock it up. Jamming usually happens when using
propane gas if the gas pressure between the gas tank and
the water heater’s gas regulator has not been reduced. See
Page 14 for recommended correct gas pressure. To unjam a
regulator, consult your gas supplier.
3. Pilot orifice or gas valve is dirty
Clogging of the pilot burner can be caused by dust in the
air or dirt in the gas. The pilot orifice or gas filter may need
to be cleaned or replace.
4. Water valve assembly needs to be checked
If the pilot orifice is clean, the water valve assembly should
be checked. The adjustment screw on the water valve micro-
switch may not be tight enough (Fig. 15). Remove central
cap beneath micro-switch assembly, carefully loosen the
adjustment screw until the pilot light ignites. At that point
retighten the screw one and a half turns.
5. Pilot electrovalve switch may need to be replaced (See
Fig 17).
Call your service person or call: Canada 1-800-663-8405,
U.S.A. 1.800-824-7337.
6. Electronic Control Box may need to be replaced, (See
Fig 17).
Call your service person or call: Canada 1-800-663-8405,
U.S.A. 1.800-824-7337.
Pilot does not spark with
water flow
1 Close water tap
2 Remove screw cap and
unscrew adjusting screw til
sparking starts
3 Screw in turning one and
half turns more
4 Replace screw cap
Pilot is always sparking
without water flow
1 Close water tap
2 Screw in adjusting screw, till it
stops sparking
3 Continue to screw in turning
one and a half turns more
ADJUSTING
SCREW