Bosch SGS4002 – sensor on back of soap dispenser

[windy1]

Just been resolving a problem with the soap dispenser. Whilst removing the main door (not the control panel part) I dislodged a spring clip with a small circular metal object attached and 2 wires.

Took me a while to figure out where it came from but then refixed it to the top edge of the soap dispenser so that it rests on the metal of the door. Also it seemed to be coated with some kind of silver speckled grease.

Any ideas what the purpose of this device is? Could it be some kind of heat sensor (hence heat conducting grease?). But why sense the heat at the top of the door?

[CJAPeterborough]

Re: Bosch SGS4002 – sensor on back of soap dispenser

according to the support site its a 65C temp regulator…

https://www.bosch-eshop.com/eshop{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d}28bD1 … SHOPTYPE=S

[clivejameson]

Re: Bosch SGS4002 – sensor on back of soap dispenser

Yep, it’s a thermistor (temperature sensor) and the silver grease is heat transfer compound 😉

I would imagine it’s placed there for a couple of reasons…firstly if there is insufficient water due to another fault then the pcb won’t pick up a temperature rise and therefore throw up a fault code and abort the cycle, secondly there’s less distance for the harness to reach it (cheaper, and the wires don’t get flexed at the bottom of the door)

[windy1]

Re: Bosch SGS4002 – sensor on back of soap dispenser

Thanks for replies and link to parts diagram.

Plausible theory on temp sensor positioning but seems a bit complex to rely on door contact temp to equal water temp. Or is there another temp sensor in the water?

Also not sure about fault codes as this particular machine has no display unless there is a diagnostic socket somewhere?

[clivejameson]

Re: Bosch SGS4002 – sensor on back of soap dispenser

windy1 wrote:

Plausible theory on temp sensor positioning but seems a bit complex to rely on door contact temp to equal water temp.

Actually it’s probably the simplest way of doing it 😉

…and having looked at the tech this is indeed the base model in the series so no pcb or fault codes!

[Author]

Posts