Normally the tenants understand.If you're having consistent issues with a tenant abusing the HVAC only (if they are abusing other items then it may be helpful to find a new tenant), I know some HVAC companies offer an annual plan with a certain number of visits per year at a flat fee.

I just bought a two flat with a similar situation except they have 10 animals . 

@Evan Bell I can't get excited about business plans.  

Then charging tenants additional cost can bring extra funds and you only pay the flat fee for internet service thru your provider. 

Brokerages may need to adjust their business models, which could open up opportunities for cost-efficient, flat-fee models or other discount real estate services.

I'd recommend owner occupied 2-3 flat for your first one.

The compensation amount must be written in an object format (i.e. percentage of purchase price or flat fee) and not be open-ended.

Background:Miami-Dade Condo property.I am a first-time seller.No mortgages or loans on my property.Standard Florida Realtors Association / Florida Bar AS IS Purchase Contract.Buyer in default on various provisions and must proceed to purchase as a cash purchase, per contract, so there should be no financing related title charge son my end.I am looking for a flat fee or low-cost title company to assist me with the seller side of the closing and coordinate with the buyer's title company.

I'd call all but the small area that is being carved out and renovated by Dan Gilbert a flat out warzone.  

I chose them due to the flat fee they have on transactions which works for me and my situation.