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Hi,
I have a Hoover HD97E dishwasher which has developed a fault. Whilst running a program, the pump seems to stop for no reason. If you flick the door catch it resumes. I have tried shorting out the door switch but no joy (also, although the pump has stopped, the timer continues to count down – the display does not flash like it does when the door is open). I have also checked the level pressure switch which seems to be fine (measured output with a DMM whilst filling/emptying the machine by hand).
Any ideas anyone?
Re: Hoover HD97e problem
Hi,
Are there any error codes showing on the display? There is another poster with the same model, further down the forum page, showing an error code.
You state that the machine operates “if you flick the door catch…” (do you mean quickly open / slam shut?).
If it does operate by slamming the door, it could indicate several possibilities:
The pressure vessel in the sump area may be clogged with sludge; slamming the door may reset the air pressure. This would require the attention of a competent person/engineer.
There may be a wiring loom fault, possibly in the door hinge area. This would also require an engineer. Wiring looms are the first ‘spares’ to become obsolete in some cases.
I gather from this site, that the electronics boards can also play up, which could be expensive.
Unfortunately, since Candy took over Hoover in Europe, technical info has all but disappeared.
Your machine might still be under guarantee. Hoover machines usually have a 5-Year Parts Guarantee; though you HAVE to use the official Hoover engineer, and pay almost £90 call-out charge. It may be the best option, in the long run.
Re: Hoover HD97e problem
Hi,
Thanks for the reply – here are some answers to your thoughts.
1. There are no error codes showing
2. At first, I re-started the machine by opening and closing the door but I soon realised it was the action of operating the microswitch which did the trick. I hold the door closed and operate the handle so the door remains shut but the circuit is opened and closed again. The machine can also be re-started by simply turning it off and then on again. In other words, it seems to be the action of removing and then re-applying power which kicks it back into life. Strangely, the power is not removed for long enough for the controller to think the door has been opened as the program just continues as normal (if you open the door properly, the program stops and you have to press START when you close the door).
3. I’ve had it t bits and cleaned/de-scaled all the pipes, pressure vessel, sump,etc. even though there was no sign of scale build up or gunk anyway.
4. I’m loathe to pay Hoover 33{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} of the cost of the machine only to find they fix it with an inexpensive part (or indeed none at all). Sure, the parts guarantee is value for money if you need a new pump or a new control board but otherwise it seems a rip off.I was hoping someone would say that a pump stopping and re-starting when you re-apply power was a known pump problem rather than a specific problem with this machine. Guess life’s not like that.
I’m an electronics engineer by trade and if I were faced with this problem at work I’d simply put a meter across the pump terminals and see if the there was power present even when it had stopped. If not, I’d look at the output from the control board (I managed to acquire a wiring diagram for the machine so I know what goes where). For some reason, I feel reluctanct to do this in my own kitchen at home – perhaps its that combination of electricity, water, and the fact the bit you want to get to is underneath the damn thing….
Re: Hoover HD97e problem
Maybe the controller board(s) is/are faulty. Have you checked for dry joints/loose connectors/singed components?
I wonder if the door catch has cracked/split/ lost a vital piece of plastic…?
The only other thing I can suggest, is to replace the door microswitch (the whole interlock assembly may require renewal…they tend to come complete). I presume there are no adjusting screws?
POWER OFF & PLUG OUT BEFORE REMOVING ANY COVERS 😀
Re: Hoover HD97e problem
I have discovered the following:
The pump is a permanent split capacitor type. When its running, there is 240Vac across one coil, and 120Vac across the second coil (with the capacitor in series).
When the pump stops, there is no voltage being applied to it.
The pump is controlled by a Triac (Philips BT137). The gate of the triac is controlled from the microprocessor via an NPN transistor. When the pump starts, a DC voltage appears to be applied to the gate of the Triac. After a while, the voltage on the gate disappears but the pump continues to run. When the pump stops, there is no voltage on the gate (but, then again, there wasn’t any voltage there when it was running). I have tried replacing the triac but the fault remains. When I flick the door switch, or power off and on again, there is still no voltage on the triac gate but the pump starts to run again.
Anyone any idea what is going on here?
Thanks.
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