If a new system and it is performing satisfactorily plus you are changing air filter on a regular basis, electric usage and comfort are good, then I think every other year service is fine. When you reach year 5, then once a year would be satisfactory.

IMO

I suggest you develop a good relationship with a trustworthy company and tech who can do the work for you. Also, getting everything checked out before heating season kicks in full gear will save you a lot furstration as good techs are very busy and you don't want to deal with less experience techs who can make bad situation worse. You should look into yearly service contract with a HVAC company. You may also get a home warranty if condo does not come with one. I have seen people benefit with these warranties. I have never had one but I wish I had it when I started having problem with my Heat Pump and AC units.

IMO.

Well there are two different opinions.

I would gather all documentation of new system including operating manual and store in a safe place.

Do establish a relationship with a reputable dealer.

Know your warranty on existing system. I am not opposed to an extended warranty from the manufacturer as long as price is reasonable. I am opposed to purchasing extended warranty from third party HVAC warranty companies. They have a terrible reputation in the industry.

IMO

I have read about people trying to get their HVAC system repaired through a home warranty. In most cases the results were bad.

Thank you all for your comments re: my electric heat pump....I will call the local company who serviced my furnace in the past and have them take a look at it.....and I will be sure that the filter is always replaced as needed......emaemes

I think it's best to have regular check of half year.