Filling problem on Hotpoint Aquarius dishwasher

[Roland Luke]

I have a Hotpoint Aquarius DF61 dishwasher. Can someone help me diagnose the following fault?….

When filling, the water inlet valve opens and closes intermittently, up to 15 times, before the correct water level is reached and the machine starts (or continues) with the wash cycle. Also, water leaks from the junction between the filling array (sometimes called the metering tank) and the pressure chamber, during filling. See attached 3 photos. (Prior to the fault there was no leak at this point, or anywhere else.) I have checked the following:

a) Filling Array: There was debris on outlet side of the array, at the top of the inverted U and around the air inlet valve. I flushed this out as far as possible; some still remains around the air inlet valve (see photo 3) but the valve operates freely. I don’t think this debris can be connected to the fault, as it is on the outlet side and the fault is on the inlet. No deposit is visible in the inlet side of the array.
b) Inlet valve: This seems fine. To test, I ran the water from the valve into a bucket instead of into the machine. It operated correctly i.e. it didn’t open and close intermittently, as it does when connected to the machine (video available for emailing). Then, with the inlet valve connected to the machine, I physically prevented the level switch and safety level switch (on the pressure chamber) from activating. The inlet valve still opened and closed intermittently, so it appears to be getting a signal from somewhere else. With a meter, I conformed that the power to the valve solenoid is indeed being interrupted.
c) Level switches: I checked the level control mechanism – the diaphragm activates the limit switch correctly, when the water reaches the required level. I also checked the safety level switch – the floats in both the pressure chamber and the machine base activate the limit switch correctly; as expected, this shuts the inlet valve and starts the drain pump.
d) Blockages: I checked for blockages in the pressure chamber and in the pipe leading from the pressure chamber to the sump. Also checked for blockage in the drain pump (removed the cover over the impellor – all clear). Further, checked for blockages at the inlets to the tank (see ‘A’ and ‘C’ in photo 2) – found nothing.

NOTE: There is no model number anywhere on the machine – I’ve checked EVERYWHERE. I’m told that it was built by Bosch – this seems correct as it is (internally) identical to the Bosch Classixx. It’s about 10 years old and is operated by an electro-mechanical timing switch.

[electrofix]

Re: Filling problem on Hotpoint Aquarius dishwasher

model is at the very top of the door on a clear label. look on the stainless part by the door latch. don’t look directly down on it look slightly from the side

and yes its a bosch built machine

to answer I comment no there is no grommet

also if you run it with the side off does the red float go up and stop the valve ?

Dave

[iadom]

Re: Filling problem on Hotpoint Aquarius dishwasher

Will also add that this machine is around 17 to 18 years old at least. 😉

[Roland Luke]

Re: Filling problem on Hotpoint Aquarius dishwasher

Thanks for the tip about the model number, Dave. I didn’t see it previously because it a small amount of soap residue made it invisible. The model number is DF61P.

The red float in the pressure chamber moves a little, but not enough to activate the limit switch. To make sure, I held the float down manually so that it couldn’t trigger the limit switch – made no difference, the inlet valve still opened & closed intermittently.

[electrofix]

Re: Filling problem on Hotpoint Aquarius dishwasher

since everything is clean the next suspect is the inlet valve. To be certain someone who has professional electrical knowledge would have to test the supply to the valve as it fills. if its constant but the water still goes on and off then its faulty.

if you need one the bosch part is cheaper see

https://shop.ukwhitegoods.co.uk/catalog … /?q=167025

Dave

[Roland Luke]

Re: Filling problem on Hotpoint Aquarius dishwasher

From the following tests I concluded the inlet valve is OK:
1. I disconnected the hose on the outlet side of the valve and ran the water from the valve to a bucket, instead of into the dishwasher. If the valve was the cause of the trouble, it would have opened and closed intermittently, as it does when the water is routed into the dishwasher.
2. I measured the electrical supply to the valve. When the valve is opening and closing intermittently, the current through the valve solenoid starts and stops intermittently. If I close the water isolation valve, so that water can’t enter the dishwasher even when the inlet valve opens, the voltage across the valve terminals jumps from 0 to 230V when the dishwasher needs water. I can hear the valve opening and the voltage across the terminals stays constant. As soon as I turn the water isolation valve back on and water starts flowing to into the dishwasher, the electrical supply to the inlet valve fluctuates.
What else, apart from the level switches, can signal the inlet valve to close?

[electrofix]

Re: Filling problem on Hotpoint Aquarius dishwasher

if level and overflow switches are ok its down to the timer

Dave

[iadom]

Re: Filling problem on Hotpoint Aquarius dishwasher

The machine has a two stage fill sequence, initial fill for each programme is controlled by the pressure switch. This is followed by a timed fill of 55 seconds controlled by the timer.

As far as the leak from point B is concerned I can say that I have encountered this on only one occasion on a Bosch dishwasher. In spite of changing both the metering tank and pressure chamber I was unable to eliminate the problem completely. 🙁

[Roland Luke]

Re: Filling problem on Hotpoint Aquarius dishwasher

Can anyone help with the following?…

Further testing showed that the inlet valve opens and closes intermittently because there is a water flow problem, which I don’t understand. The photo/notes below explains…

[electrofix]

Re: Filling problem on Hotpoint Aquarius dishwasher

then it has to be some sort of blockage
as water enters the chamber it has to exit at the same speed

if you cant see a blockage try lowering the flow rate from the tap

Dave

[Roland Luke]

Re: Filling problem on Hotpoint Aquarius dishwasher

Is the machine designed such that water entering at ‘A’ flows through to the pressure chamber? This seems illogical. Surely water entering at ‘A’ should flow directly into the sump and should not go via the pressure chamber? Am I correct about this?

There is definitely no blockage between the pressure chamber and the sump.

[Martin]

Re: Filling problem on Hotpoint Aquarius dishwasher

Try turning the flow rate down as Dave suggests. Clearly you have extremely high water pressure which is less than ideal, so reduce the flow rate by 50{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} and try again. :tup:

[Roland Luke]

Re: Filling problem on Hotpoint Aquarius dishwasher

I’ll try turning the water pressure down, but I’m sure there is something else amiss. The filling problem appeared suddenly, after changing the water supply hose. When I’d fitted the new hose, I turned the water back on too quickly and there was a ‘water hammer’ effect i.e. water rushed into the machine, then stopped very abruptly. After that the machine wouldn’t work, due the problem we’ve been discussing.

[Martin]

Re: Filling problem on Hotpoint Aquarius dishwasher

Thought as much! Changing that hose was when the fault started so clearly it’s a water pressure problem after all. Just turn it down a fair bit and status quo will undoubtably resume. 😀

[Roland Luke]

Re: Filling problem on Hotpoint Aquarius dishwasher

I tried throttling the supply valve under the sink – lo and behold the dishwasher works! The valve is only just cracked open – anything more and the fault reappears. I’m puzzled as to why the change, but it works and I’m grateful.

Thank you Dave and Martin for your help in solving this one! And thanks to Banksie for other very useful information.

[Author]

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