How can I determine the problem on a F&P DW920?

Thanks for your help.
I'll see if I can get the control board out and see if I can do it.
If I can get it out and find it I should be able to replace the triac.

Mark
April 2014

You won't need the multimeter. The main control board is faulty. Everything underneath i.e. drain pump, wash motor, inlet valve are live as soon as power is switched on, Only the heater has no power to it until the control board relay switches it on. The control board switches the neutral side of each circuit on to make that item work.i.e. the neutral side of the drain pump circuit switches on and drain pump will run until the neutral switches off again. The inlet valve opens when the neutral on the control board switches on. If valve is opening as soon as power is supplied then that means the triac switch on the control board has failed in the on position. If you are any good at repairs to pcb then you can repair it by replacing the triac on the board. If not then you will need a new control board. I can help you locate the triac and then you just unsolder the 3 pins and solder in the replacement one.

Lincoln Appliance NZ
April 2014

As soon as power is turned on at the wall, the inlet valve opens and start flow, without the panel even being lit or touched. Start, stop or pause has no effect on the inlet valve, it keeps flowing as long as the main power is on. As soon as it is switched off at the wall, the valve shuts. I have a multimeter.

Mark
April 2014

Ok then it sounds like either the inlet valve is faulty or the main control board. Sometimes the return spring inside the valve becomes weak or there is a build up inside which stops the valve from shutting off. You can test for that by starting the fill. When you hear water entering the dishwasher press pause and see if the flow stops immediately. If it hesitates for several seconds or does not stop at all then replace the valve. If it stops quickly then you will need to check the power supply from main board. Do you have a test multimeter?

Lincoln Appliance NZ
April 2014

Both pumps seem to be working correctly. The humming is a buzz and seems to relate to the inlet valve. when disconnected the humming stops and water does not flow. It seems whatever controls the inlet valve is leaving it shut open.

Mark
April 2014

One other thing is that when you press start button the first thing that happens is the drain pump will run for about 30 seconds to clear away any dirty water left from last wash. Then drain pump turns off and fill starts. If you can still hear a humming sound it may be the drain pump or the wash pump not starting.

Lincoln Appliance NZ
April 2014

When it starts filling does the wash pump motor start running? If it is not running the dishwasher will over fill or come up with an error code U1. We need to establish first of all that the motor is running at that fill time.

Lincoln Appliance NZ
April 2014

Sorry - didn't make a difference..existing capacitor seems to be fine. Could it be inlet valve or relay ?

Mark
April 2014

Thanks I'll give it a go.

Mark
April 2014

Change the start capacitor for the motor. Open the lower panel below the door. Make sure power is turned off at wall plug first. Look inside and on the right hand side near the front is the capacitor. A white plastic cylindrical object with two wires. Fit a new one. Wires can go on either terminal. The reason for this is the 920 does not have a fill sensor switch. Motor has to be running while it fills and the control board monitors how much drag is on the motor impellor. When the right amount of resistance or drag is recorded it will stop filling. The hum you heard would be the wash pump motor trying to start. The capacitor gives it the ability to start.

Lincoln Appliance NZ
April 2014