Author Topic: Overriding thermal cut out by holding down power switch? (Read 3854 times)

Chach13 · « **on:** March 15, 2020, 07:47:44 pm »

Hi, I have pulled out my old DC33 from my shed and thought I'd try to figure out a problem that I have had with it for a few years. The machine switches off after a while. I have checked all filters, they're clean and there are no blockages so far as I can see. I can't smell anything funny either. When I press the switch and keep it held it works fine. I do not know if the switch is the problem. I took the switch off and it clicks fine. I am just wondering now if my holding the switch down is overriding the thermal cut out, if so I would know then that the problem is likely to be with the motor. I cant see anything wrong with the power cable either. Your thoughts and advice would be welcome.

ryevac · « **Reply #1 on:** March 15, 2020, 09:26:50 pm »

if it was the motor at fault - it would shut off even if you hold down the power switch.
Holding down the switch has no bearing over the thermal cut out.
The switches internal contacts become dirty and pitted over time, thus causing high resistance - this combined during use causes heat and the switch plate contacts fail.
Change the switch.
They are prone to failing after so many years.

Chach13 · « **Reply #2 on:** March 16, 2020, 01:11:22 pm »

Thanks for your advice. I will order a new switch. I have inspected the existing one, looks OK visually no signs of pitting or dirt and clicking fine.

Chach13 · « **Reply #3 on:** March 19, 2020, 02:42:51 pm »

UPDATE:

So I have replaced the switch, and I still have the issue of the machine switching itself off after 4 minutes of use. I am not able to re-start unlike before where I thought if I continued to depress the switch it will remain switched on. How do I test the cable, or is it a case of having to replace the motor? It seems to run fine when it is working.

ryevac · « **Reply #4 on:** March 19, 2020, 03:14:37 pm »

motor in that case then, you did say "When I press the switch and keep it held it works fine."
incorrect diagnosis.
replace the motor, you may have a problem with the old motor surround gasket being too smaller depth for the new motor, in which case you will have to use a different surround from an 07/14.
Some 33 models have the bigger depth motor fitted from new, some dont.
Throw away the old post hepa filter too if it looks tired