[GJPalmer]

Re: No dryer heat on Hotpoint WD640

😀 Thank you all for your help problem sorted I did not try the unit out long enough and was expecting the voltage on the heater to be a pulsed output i.e the applied voltage on full at first then cycling on /off at a lower pulse rate when the temp is at its desired level. This method of temp control is some times used on injection moulding machine heating. A thermocouple is used to input an analogue input P.L.C card and this information is then used by the program to send a signal to a SSR(Solid State Relay) when the desired temp is near it setpoint the mark space ratio signal to the SSR altered to give a shorter on time this is to cut down temperature over shot
Once again thanks for everyones help

[GJPalmer]

Re: No dryer heat on Hotpoint WD640

Thank you Tim for your posts.

I have only run the dryer up for about 15-20 minutes did not see any reduction in the applied voltage to the heater element.

I then unplugged the machine and did a resistance test on the thermistor this was at about 950 Ohm’s, was not able to check the temperature on the surface of the heater box.

Is there a set resistance on the thermistor when the heater voltage drops off?

If so can I test it with a resistor of that value?

Thank you

– GJPalmer

[GJPalmer]

Re: No dryer heat on Hotpoint WD640

I have already removed the heater boxed and cleaned it of all the fluff after first removing the 13 amp plug top.

What is your preferred method of testing the heater box assembly?

Also how do you check the PCB with a multimeter then please?

Thanks for any reply

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