My Bosch WTL5500 has stopped working. The internal computer is obviously functioning because the count down time and all lights are normal, however no sound comes from the relays and the machine remains non-moving and cold. Inside the heater is a small black component marked "NTC" - I think this is the temperature sensor. My meter tells me that this component appears to be open circuit. I believe at cold there should be some reasonably low resistance. I could prove that this is the problem by bridging the sensor wires - is this sensible? Also, even if I have located the problem, what is the chance of being able to purchase this component or a complete heater? I am in the UK so a general "no chance" or "keep searching" will do !!!!

Steve Coppard, January 2005

if open circuit yes - disconnect the sensor (side panel off) and the front panel will flash a light (cupboard dry) to say it can not read the sensor. Worth changing should be 120 ohms or so.
Do not know if this will make it run though.

mike, March 2012

Ann and John... the NTC is below the button you pushed, which was a thermal cutoff switch. You probably reset that, which made your machine work.

kirk, October 2008

Hi Steve
Had the same fault as you - was looking for a clue when I saw your question... we cleaned everywhere we could reach and exercised the connectors everywhere, pushed anything that looked like it could be pushed.. etc including what we took to be the NTC - and hey presto the fault disappeared - ie it was a gremlin, not a proper failure.
Doubt this helps you?? but it 's hopefully bought us time to save for a replacement.

Ann and John, September 2005