Oil filled Heater will not turn on and heat.

Have you checked the circuit breaker or fuse for the circuit that your heater is on? It's possible that you had something else come on that, combined with the current draw of your heater, popped the breaker. If that turns out to be the case, turn the heater switch from high to medium or from medium to low so that you're drawing less current.

What type or heat is it

Could be that the thermostat is disconnecting because it senses too warm.

Plug the heater to the wall, turn on the switches.
Turn the thermostat knob all the way to min. It should make a click sound and the heater should not get warm.
Turn the thermostat knob all the way to max. It should make a click sound and the heater should get warm.
If the heater is still not warming up and/or you don't hear clicks, then the heater has bigger a problem.
With the cheap prices of the heaters, it is not worth trying to have an electrician check it out. Just buy a new one.

check oil overtemp senser or heating element, some of the newer ones have a circuit board with default codes, check for codes,unplug, plug back in and see if it works

make sure the thermostat dial is not turned all the way down. The red rotary dial, set it to 6.

very little sound and it does take quite a while to heat up .. you should feel warmth in 15 min .. if it doesnt heat at all then there might be an open "over temperature" fuse inside ... one of the good things about this heater is that its so quiet ..

1st, check the electrical cord plug; because of the hielectric demand, thesaes plugs overheat and form a burn coating on the prongs that stops the hilevel of electric but allows a small level ofalaectric that still lights the lights but no power for heat.
2nd, the thermostat is not making contact: it is a bi-metal contactor that sometimes burns or loses its strength and no matter where you turn it it wont work. You can simply cross the terminals of the thermostat to see if you get electric flowing (you have to open the oen housing to do this.
3rd, the element could be burned-out or (as often happens) the connection to the heat element burns-off. Again, you need to open the end housing and look, or take it to a small appliance repair place.

Try calling delonghi america at 1800 322 3848