space heater controller repair help

[Petrushka]

Hello, I am trying to repair my space heater. Basically, my heater sometimes will still heat even if switched off, or when I set the thermostat to a certain temperature and the actual temperature and readout is higher than the setting the heater will still stay on when it should go off. The only way to get it to trigger the relay to shut off the heater is to toggle the thermostat setting button.

It's a Honeywell (KaZ Inc. HZ-709) oil filled space heater. See images:

 

[Bluejets]

Sounds like a temperature sensor problem given the "toggle" aspect.
Could also be a sticky relay.(more likely)
With the unit re-assembled, and the fault present, a sharp wack in the vicinity of the relays could do the same job as toggling and give an indication that the relay is sticky.

Location for the sensor could possibly be on the control panel or more likely in the airflow somewhere.
Best to show both sides of both boards.

Just be aware that these particular units have a very crude mains reduction arrangement which is ok for totally enclosed devices BUT once opened, any section of the unit can expose lethal mains supply, even in the low voltage areas under certain circumstances.
Not the sort of things for amateurs to be playing with.

 

[Petrushka]

Thanks, @Bluejets! I tried giving it a wack but to no avail! The only thing that works is toggling the temperature switch.
I'm thinking it may not be a relay after all but perhaps something else?

 

[Bluejets]

my heater sometimes will still heat even if switched off,

Only one thing can do that and that's a stuck relay.