Bosch Appliances WR430-7K manual Trouble Shooting, No Spark AT the Pilot, Adjusting Screw

Maintenance*

If faults occur on the flue gas safety device, proceed as follows:

-Undo flue gas safety device fixing screw.

-Unplug igniter unit connector.

Replace damaged component with new one and refit using the reverse of the procedure set out the table above.

Function check*

Flue gas safety device function check:

-Disconnect flue pipe

-Replace with pipe (about 50 cm long) with sealed end

-Fit pipe vertically

-Start up appliance at rated output and set temperature control to maximum temperature.

Under those conditions, the appliance should shut down after two minutes. Remove temporary pipe and reconnect flue pipe.

* This work may only be carried out by an approved engineer.

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 hot 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 13 for adjustment. Replace the microswitch if the adjustment does not solve the problem.

Fig. 13 - Microswitch Adjustment

TROUBLE SHOOTING

Introduction

The Bosch WR430-7K burners are activated by a water flow valve. Numerous water related problems can cause this water valve to malfunction such as: Insufficient water flow volume to activate the burners at its minimum flow requirement; Dirt in the water flow valve causing it to malfunction; Sediment build-up in faucet aerators, or shower heads; Uneven pressures between cold and hot, (with single lever faucets) Plumbing cross overs. These water flow related problems can cause the heater to deliver less than its full output, or to fail to ignite or to shut down completely.

Problems are stated in upper case, bold face. Most common causes for the problems follow in order of likelihood. The suggested solutions require that the cover be taken off. To do this, remove incandescent particle tray, pull off the temperature adjustment knob and unscrew and remove the plastic collar. Pull main cover out toward you and lift up and out.

NO SPARK AT THE PILOT

1. ON/Off switch is not “On” (Position ).

The On/Off switch is located behind the flipdown cover plate on the front panel strip. See fig. 9.

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 WR430-7K 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 seconds. 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.

ADJUSTING

SCREW

Pilot does not spark with		Pilot is always sparking
water flow		without water flow
1	Close water tap	1	Close water tap
2	Remove screw cap and	2	Screw in adjusting screw, till it
	unscrew adjusting screw til		stops sparking
	sparking starts	3	Continue to screw in turning
3	Screw in turning one and		one and a half turns more
	half turns more
4	Replace screw cap

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