Fisher & Paykel Dryer Stops, Beeps Constantly, Won't Run?

my Fisher Paykel auto sensor dryer keeps stopping and beeping, i have to stop it and and re start. This started after I forgot to keep the door to the laundrey open when drying a full load, now the dryer only works if I heat the room to 25 degrees, and even then it intermitant, is it time to buy a whole new dryer or can it be repaired? I'm a single mum and have a newborn baby in the house so need to know ASAP whether to plan to replace it.