Chefquip 25DP Dishwasher problem

Hi all.

New to the forum and could use a little advise. I hope you don’t mind. I have a Chefquip 25DP dishwasher that has gone rogue. I was wondering if anyone has any experience with this machine or even a different machine where the the symptoms I am getting are concerned.

I managed to find a very primitive wiring diagram. Not a fuse in sight to be seen on the diagram and it’s full of non standard symbols. Which doesn’t mean there aren’t any fuses of course. Checked all the relays. They all work fine. I notice that there is a level pressure switch in the wash cycle circuit that prevents the wash cycle from running if the tank is empty.

The problem began with the wash cycle start button not working.

Replaced the start button.

Powered it up and started the wash process. Tank fills, 20 minutes later the temperature ready light comes on. Press the new button and wash cycle begins.
Wash cycle ends after two minutes. So went away happy. An hour or so later I get a call to say that the button doesn’t work. I asked the lady how she uses the machine and what I found out is that the way she normally uses the dishwasher is that she doesn’t drain after every wash (it’s not an auto drain. Its a manual switch to drain). She normally re-uses the same tank of water if the dishes are lightly soiled (cake crumbs etc) and that’s been working fine for years. So what she does is just switch it off at the end of a wash, switch it on again an hour on so later, water heats up and she then presses the wash cycle button when the temperature light comes on. That’s the routine and its been working fine like that for a coupe of years.

So, in summary, what we have is: tank fills up, water heats up, new wash cycle button works. Turn machine off at control panel. Turn machine on an hour or so later, tank is already full so goes into heating mode, water heats up, temperature ready light comes on, new wash cycle button doesn’t work.

Since the level pressure switch only gets pressurized during filling I figure that the level pressure switch diaphragm has a leak, slowly losing pressure and eventually opening the switch and disabling the wash cycle circuit. Makes sense? So I checked the switch and found evidence of overheating. I replace it.

Didn’t solve the problem AND actually made it worse because now the new wash cycle button doesn’t work even after filling the tank at the start of the process.

So I am sitting there staring at this thing, with it’s temperature ready light on, trying to figure out what is going on.

There is a 3 cam electro-mechanical timer in the mix. I can see that the wash cycle start button is connected to cam 3 in the diagram. So what I did was to hold down the the new start button and then manually flick the switch above cam 3 on the timer. The wash cycle began and the cams on the timer start to turn. The process ran to the end of the wash cycle as it should.

I’m not really sure how this timer works ie: whether the switch SHOULD start the timer cam turning, as it did when I flicked it manually, or whether the cam is supposed to turn first and flick its corresponding switch. Know what I mean? Any info on that would be appreciated. Maybe I need to replace the timer??

Also, I am thinking there might be a synchronicity issue. Timer cams and relays and such. I know that on some dishwashers there is a reset button. I presume the purpose of that button is to resynch the machine. This 25DP doesn’t have a reset button. Is there a way I can resynch a machine that doesn’t have a reset button? By putting a voltage across the timer perhaps and turning it to a certain start position? Does that make sense?

Anyway, that’s it. If anyone can shed a little light I would appreciate it. Sorry it’s a bit long winded but I wanted to try and be clear as to what the problem is.

Thanks to all.