Whats wrong next to our gas furnace? It goes out and wont turn on when we move the thermostat...

It goes out and wont turn on when we move the thermostat lever. Then we enjoy to press the reset button. Its a older furnace, probably from the 1970's by Williamson. Sometimes bad press the reset button, the boiler will kick on and later 10 seconds then it shuts off. Sometimes unwell press it and the boiler comes on, furnace will come on and then shut stale in 5 minutes. Other times the furnace will come on after i press the button and will run mundane. Then shut off and wont come support on until I press the reset button again. And some other times it will run normal.
Stupid drying isn't working...?
Answers:    How matured is the thermostat? If there is a short contained by the thermostat it can cause similar symptoms. Try getting a topical stat that is compatible beside your system. If that don't work you should call a pro. Good luck.
How do I powerflush a radiator. The radiator...
i'd beckon a person who specializes within such things and have him check it out.