Hotpoint Aquarius WF250 Prewash light flashing?

[stephen101264]

My Hotpoint Aquarius washing machine WF250...

Prewash fine
Mainwash fine
drains good
All 3 solenoids tested, working fine & have water, no blockages in screens.

The prewash light flashes when a cycle gets to a rinse, no water at that point either?

Hotpoint online say this means no water.

Had a look at the mainboard underneath, cannot see any burnout or loose wires.

I am guessing at a mainboard fault....any ideas? and worth fixing?
also could I plug in a second hand motherboard if I could get one or is there any software issues/ special set up needed?
Thank you for any replies?

 

[rocks1]

Have you checked the rinse valve. Does it fill on rinse. Does it overfill check for a small hole in pres pipe

 

[stephen101264]

Does not fill on the rinse just spins slowly, no water going in at that point at all, no holes in pre pipe, neither does it overfill,

works fine up to that point, the rinse valve is in working order.

 

[rocks1]

How do you know rinse valve works. Have you tested it for continuity or swapped it over. Blow the presure switch it might be stuck.

 

[stephen101264]

Yes I have swapped them all around, as no water is entering on the rinse cycle there will be no rising water to activate the pressure switch.
The flashing prewash light is a fault code signifying no water, but I know all valves are good & unblocked.
As stated earlier the machine works fine up till rinse, then the flashing fault code appears.

 

[rocks1]

Then the presure switch is faulty.

 

[stephen101264]

Many thanks for replying to my post,
but why do you think its the pressure switch, I thought rising water levels pushes air up the tube activating the pressure switch, as there is no air entering my machine on rinse, the pressure switch can be discounted.

 

[rocks1]

Cos the contacts are stuck in the pres switch. I done on on mon a wma and on the 40 and 95 wash it was ok but on 60 and rinse drum would turn and no water would enter pres switch jammed. Change it all ok

 

[stephen101264]

Is there an easy way to test a pressure switch with a multimeter to confirm it is stuck on empty?

 

[rocks1]

Have you blown the presure switch you should hear 2 clicks.

 

[stephen101264]

Yes, 2 clicks 1 when blown into and another when pressure released. pressure switch terminals as follows...

4 terminals in a row left to right. Using the continuity buzzer on my multi meter.....
1 and 3 terminals buzz when there is no pressure, showing a circuit.
2 and 3, 2 and 4, and 3 and 4 terminals buzz when pressure is applied (blown into).

should 1 and 3 show a circuit when there is no pressure? confirming your prediction of a faulty switch?

I took the mainboard out also, cleaned dust off it, no noticeable water rust or dry joints, looked mint condition, but fault still there!

Did a google, apparently these mainboards sometimes suffer software faults and need to be reprogrammed or other malfunctions needing replacement.

Do you still think it's the pressure switch, perhaps stuck on empty or do the 2 clicks show it's internals are good?

As stated earlier machine stuck on main rinse, no water, currently get around it by adding cold water via soap drawer to complete cycle.

 

[rocks1]

Yes a presure switch fault