Mr heater big maxx 45000 btu

Hi ,jjust bought this heater mr heater big maxx 45000btu now, the led indicator works fine, calls for heat then the ignitor tries to ignite but no gas after the gas valve.... here's precisely what she does: 1: led blinking slowly (normal mode ) 2: turn up the thermostat, led calls up for heat and exhaust blower starts for about 30s 3:ignitor tries to light the burner then tries again and again 4: no smell of gas while doing this 5: i unplugged gas from the inlet side and there is gas going in the valvle but not trough the valve.... now my question is will she light up propane even if it is set up with ng? do i absolutely need a 24v thermostat to fire it up? i know the machine can go in shut down mode ,but how can you unlock it??? what could be all the causes and how to check? please some help quick would be much appreciated