We have a Bosch ceramic hob model no 9000329649, cooking with rear 2 rings yesterday. They will not switch on, front 2 are OK. Grill and oven fine.
check them with a meter and check the infinite switch's also
are typically either a coil type, solid type or a ribbon coil as used in smooth top ranges. All of these consist of a heating wire that uses electric current to produce heat. Coil type elements can be checked for continuity by removing them from the terminal block and testing them with a multi-meter.
You should also inspect the terminal ends for signs of heat damage or corrosion, and if present, you should replace the terminal block or receptacle at the same time. You will need to remove power from the range to change the terminal block. Solid elements and smooth top elements require raising or removing the main top to gain access. You will need to remove power from the range before lifting the main top. Continuity can then be checked with a multi-meter, once you have removed the wires from the element terminals.
The infinite switch
on the control panel controls the power to each surface element. If you have no heat at an element and the element and terminal block check ok, then you may have a defective infinite switch. Disconnect power to the range and remove the console back panel. Locate the switch and check for overheated wires or faulty terminals first. Test the switch's contacts for continuity with a multi-meter. If defective, replace the switch.
1.If the infinite switch does not appear to be defective, then you should check for proper voltage to the switch. This is a live high voltage test and should only be performed by qualified persons. (Locate the suspect switch for testing. Label all wires and terminals before disconnecting. A close up digital photo may be helpful.
2.On the burner control switch the terminal labeled "P" leads to the burner indicator light. The terminals labeled "H1" and "H2" lead to the burner element and the terminals labeled "L1" and "L2" (sometimes "N1" and "N2") are the power supply wires.
3.Set your multimeter to ohms setting x1. Turn the burner control to the highest temperature setting. Place one probe on pin "L1" and the second probe on pin "H1". The resistance measurement should be very low, zero to twenty ohms. If the test shows high or infinite resistance, the burner switch is defective.
4.Repeat the step above for the terminals "L2" and "H2".
5.If the control passes that test, turn the temperature setting to about the middle of the range and repeat the previous two steps. This will test for an intermittent problem with the switch. If the test does not show continuity with very low resistance, the switch should be replaced.
6.With the switch turned to the "Off" position, the resistance on each of the pairs of terminals tested above should now show no continuity or a reading of infinite resistance.
7.A test for continuity between "P" and "L1" when the burner control switch is on should show continuity. The light should be on whenever the control is turned on. If your test shows continuity, but the light does not operate, it is likely the bulb has failed.
If the burner switch shows high or infinite resistance, the switch is not passing along current to the burner and so the switch should be replaced. )
Jan 10, 2017 |