My Siemens/Bosch dishwasher won't heat properly

martinlarsenApril 13, 2014

Our Siemens SE36A290SK dishwasher (identical to the Bosch model, except for the name) does not heat properly. It runs for many hours before finishing because the water never gets hot, only lukewarm, and the dishes aren't clean.

At first I thought it was the infamous "Runs forever, showing 1 minute" error caused by a defective relay or soldering on the controller board, but it does actually finish the cycle after about 8 hours. The timer starts at 199 minutes, slowly counts down to say 60 minutes, then goes up again to perhaps 130 minutes and so on. Finally it counts down to 1 minute and stays there for a long time while the machine is still rinsing. Normally it would be at the end of the drying cycle now. At last it finishes, though. It also does heat, albeit not very much, and eventually the water gets somewhat warm but it takes a very, very long time.

I have replaced the relays wity no luck. Also the solderings look fine and there are no other signs of problems on the board. Then I bought a clamp meter and measured the power consumption for the heater to be around 900 mA which explains why the water does not get hot.

Do you think the heater is defective or could there be another cause?

Basically I would like to know what I should do next to locate the problem. I am familiar with fixing stuff, having electronics as my hobby.

Thanks so much in advance,
Martin, Denmark

Thank you for reporting this comment. Undo
whirlpool_trainee

Have you cleaned the pressure chamber and the heat exchanger located behind the left side of your dishwasher?

Alex

    Bookmark   April 13, 2014 at 10:59AM
Thank you for reporting this comment. Undo
martinlarsen

Alex,

The pressure chamber has been the cause twice for a similar problem as described here: http://ths.gardenweb.com/forums/load/appl/msg0413510827197.html

Although the symptoms are much the same, there are differences not present this time:

- the special sound stemming from the lack of water in the sump
- the ability to help the dishwasher finishing the cycle by throwing 2-3 litres of water into it

Also, it does actually finish the cycle after 7-8 hours.

I am pretty sure the pressure chamber or heat exchanger isn't the cause this time. But I could check if you think it could be the cause even though the symptoms are different.

But what about the power consumption of the heater. At 900 mA at 230 V it consumes only around 100W. Even if the pressure chamber or heat exchanger was clogged, it would consume the same power, wouldn't it? I guest there is only a on/off function of the heater.

If not the heater itself, I am wondering if there could be a bad connection somewhere etc.

By all means correct me if I am wrong in my assumptions about how it works!

    Bookmark   April 13, 2014 at 2:22PM
Thank you for reporting this comment. Undo
whirlpool_trainee

Yes, the heater can only be on or off. If the water level switch isn't satisfied, it won't let the heater turn on.

I skimmed the Universal Repair Manual from the German forum (only available in German) and it says:

Machine doesn't heat or gets stuck
- does is fill?
- does it drain?
- does it recirculate?

If yes -> check for defective relay.

If the relay is okay, the dishwasher probably doesn't take enough water in -> check the pressure chamber and the heat exchanger for clogs.

    Bookmark   April 13, 2014 at 10:08PM
Thank you for reporting this comment. Undo
martinlarsen

Can you give me a link to the repair manual?

Thanks.

    Bookmark   April 14, 2014 at 3:38AM
Thank you for reporting this comment. Undo
whirlpool_trainee

Here's the General Manual and here is another one on how to clean the heat exchanger. You could also try Appliance Junk's Google Drive, which has service manuals for US Bosch dishwashers - these lack the heat exchanger, though.

    Bookmark   April 14, 2014 at 8:14AM
Thank you for reporting this comment. Undo
janerh

I have a Siemen's Hi Definition dishwasher about 6 years old. About 2 months ago it started running for about 5 hours before eventually shutting off. Water never got hot. Repairman has been out ($250) and while he got the dishwasher to now run a normal cycle, the water still doesn't get hot and dishes aren't clean. He says the dishwasher doesn't heat and that we should run the water in the sink until it gets hot. If it doesn't heat why did it run for the first 6 years. I hope someone can help. We have sold our house and feel odd telling new owners that they need to run the hot water before using the dishwasher!

    Bookmark   November 27, 2014 at 10:26AM
Thank you for reporting this comment. Undo
HerrDoktorProfessor

I'm guessing you'll either be giving a seller credit to get it fixed or buying the new owners a dishwasher.

    Bookmark   November 27, 2014 at 12:40PM
Sign Up to comment
More Discussions
Why are my frozen bananas melting?
Not sure the right forum for this, but I freeze bananas...
weedyacres
Counter depth refrigerators - who actually stocks them?
I need to replace my current counter depth refrigerator,...
yjacket86
Convection Microwave vs Speed Cook Microwave Help
We are remodeling our basement to include a kitchenette...
Teresa Cooper
Unnecessary drama with Miele dishwasher...
The salt/softener tank on my ten-year-old Miele Incognito...
howardgee
Removal of Dishwasher Detergent Build-Up
I have a Miele dishwasher in a rental unit that has...
dimond
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™