My monitor heater made a loud boom noise and the smoked. Do i need a new new one

I would call a repairman to look at what caused the boom noise. It sounds like something electrical shorted out and just need the parts that shorted replaced. A repair is generally less costly than replaceing the unit. Also, how old is your unit and has it been checked out at least yearly, preferably at least yearly just before heating season. I have seen several heat units that have shorted and caused loud noise each year. Hopefully you will get a reputable repairman and not a person whose incentive package that is linked to getting commissions for new installs. There are a couple of companies in my area that within the first few minutes will offer the advise that the system is on its last legs, and should be replaced. There was one of my clients whose was told that on a system that was only 4 years old and still under warranty. If you have problems finding a good technician, call the BBB in your area or get online with sites like Angie's list. Let me tell you if there is bad technicians out there they can be found by customer complaints and customer compliments. I try to give the best imformation and I get 80% of new business off referral from satisfied customers. Just talk to friends and family and see who they use.
Hope this helps