Bosch Dishwasher - Testing the Wash (Heat) Pump - Error E09 or Tripping the circuit breaker.

The Bosch Heat Pumps have a internal heater built into the wash pump housing.
E09 is displayed when the heater goes open circuit.
Sometimes the heater goes down to earth and trips the circuit breaker during the heating phase of the wash cycle.
This video discusses the two scenarios and how to
the Heat Pump.

[@anton_72]

Thanks a lot for this video. What I find particularly problematic with these Bosch/Siemens dishwashers is that this pump/heater is sitting at the bottom of the sink. Any more or less serious leak elsewhere in the system can cause water accumulating at the bottom of the sink thus innondating this pump. My Bosch has a well-known problem of leaking from the sidewalls which I have not so far managed to solve completely (I tried using thermoresistant silicone sealants that do the job for 1-2 years). My Bosch is around 11 years old, and I replaced 2 pumps (40 euros here second-hand). As a side note, the heating elements can now be purchased on Aliexpress, something that was not possible 2 years ago.

[@mikethk]

Very nice that you showed the last heater aswell. I cant measure anything with my multimeter, so it must be an open circuit. I feel comfortable enough now to buy a replacement. Thx. alot.

[@user-dd9fe4tt1c]

Get just the heating element as a spare. The pump will cost you just less than the whole cost of the appliance

[@zaczac3024]

I suspect these thick film heater/pump units installed in Bosch (& possibly Siemens) dishwashers have a common and serious design flaw.
Symptoms are either water will not heat, tripping mains circuit breaker and/or E09 error
The rubber seal that keeps water away from the (dry operation) thick film heater element in the circulation pump leaks.
The leaking water then corrodes the 2000W heater element at the lowest point and it fails open circuit or shorts/leaks to ground tripping the mains power circuit breaker.
I've seen several units less than 3 years old with this issue which require an NZD $185 (pump cost price) part and min two hours labour charge plus call out and GST (assuming it hasn't damaged the controller board).
I've tried and I think it's not possible to patch the defective thick film heater element, plus you need to replace the large O ring seal and reassemble the pump without damaging the O ring
Customer is looking at approx NZD $500 repair on a $1200 dishwasher, most customers just scrap it

[@theoracle6005]

Hi Zac
That's correct, water either leaks via the seal or if the sump is leaking if pools around the wash pump and corrodes it that way as well.
2hrs labour is fair and reasonable for this job including testing and pumps are expensive. So by the time you put your mark up on the part it's an expensive repair.
In these cases it makes better business sense to refurbish and install them into rental property and would have a good resale value.
The dishwasher would be maintainable with ready access to Bosch spares compared to cheap n nasty dishwashers.
These cheap units will fail just outside warranty and your stumped for replacement parts, which will most likely end up in the dump.

[@azizakkar5815]

Intresting video.thx a lot.

[@alisepehrjavan4239]

good advice

[@zakzman2633]

Thank you very much for your detailed video. I'm not very knowledgeable in this domain, but I can use a multimeter :) I measured the heating element resistance, and the reading was 8.9 ohms (nothing between the ground and either of the heating element's prongs. Does this mean the heater/pump is bad? my issue started with an E:01 code "Heat pump motor circuit fault". Thank you for your help!

[@theoracle6005]

@@zakzman2633 if you have 8.9Ohms between heater terminals and ground you have a breakdown in insulation resistance.
Did u unplug the heater wire harness and temp sensornplug before taking readings.
If not you can be measuring circuit resistance in parallel.
I unplug all connectors to the heater and I use a megger tester to measure insulation with 500volt setting to check if the resistance drops below 1Mega Ohm, ideally you want insulation resistance to be between 10Mega Ohms to 500Mega Ohms.
But if your unplugging thr connector and getting 8.9ohms between earth and heater terminals, you have a bad heater and you will need to replace the pump

[@zakzman2633]

@@theoracle6005 Thank you for the details. I'll redo my measurements after I unplug all three wire harnesses (motor, pump and heat sensor) this time. I appreciate it!

[@zakzman2633]

@@theoracle6005 Hi again... ok, I unplugged the power harness and the sensor harness to the heat pump and the readings are still the same...8.9 ohms between the two terminals (nothing between either of them and Earth/ground terminal). Measurement at the heat sensor were 9.9 (terminal one and two) 9.8 (2 and 3) and 19.7 ohms (between 1 and 3). The motor terminals readings were 12.8 ohms between each two of the three terminals. As you can see the measurements are following the correct patterns, but the values are a way lower than what you had. I'm in the US and voltage is 110/120, would that make a difference? Do the lower measurements means the heat pump assembly is damaged? Thank you very much for your help!

[@katiamanfredi7465]

Hi my Bosch dishwasher lifestyle automatic SBI69M15AU/01 is not heating the water for the entire wash cycle, i have tried several attempts but dishes go through entire wash cycle and come out greasy and unwashed. Any idea what it could be as there is no error code coming up so no idea where to start diagnostics.

[@theoracle6005]

Measure the resistance of the heater, if it's open circuit replace the Heat pump assembly

[@SamHocking]

The fault on mine was water gets trapped in the grey housing and shorts the heater element which is printed to a steel tube inside. Dissasemble, dry and then test and they're usually fine to refit. But you gotta fix the leak otherwise it'll trip the consumer unit again when enough water enters the housing in the future.

[@theoracle6005]

Hi Sam
The grey housing should have water as its a pump, the Oring seal could be compromised once its removed and reinstalled then you have a chance where water can get on the terminals and short out.
Best is to replace the heat pump if see its defective

[@mihamaker]

Is thermistor integrated in the heater pump combo?

[@theoracle6005]

Hi
The thermistor is integrated into the heat pump assembly.

[@sofroniomina3826]

relax your hand bro

[@theoracle6005]

Thanks that insulation tester puts out 500Volts.Gives a bit of a jump start if your not careful 😀