If so, crank the thermost up really high, and see if it finally heats up.

Recommend cleaning and / or generalservicing of the heating unit by a licensed / qualified heatingcontractor prior to close.Heating - Air 16 Tenants complained about not having heat on the 3rd floor.

The property is old (1913) but I updated it mostly (plumbing, HVAC including heat and ac, new ducts new roof, plumbing fixed flooring redone.)

I don't have anyone in mind for you as I don't invest in Ohio, but if you're iffy about your agent now wait until the heat goes out in Jan and you need to get it fixed asap and your agent/ PM is nowhere to be found. 

Ivy City, Union Market, H Street development, and Bladensburg Road development is heating up.

(Just replaced the heating boiler in one of the houses and that was an $8500 expense). at your $200/month expected maintenance bucket, you would need almost 4 years of savings to be able to cover a similar expense.  

Open to any agencies and willing to pay heat as part of the deal. 

If this doesn't fix it then there is probably one of the heating elements out.If that doesn't fix it easily then I would send PM and owner a letter and tell them they have 14 days to cure or you will call a plumber that advertises on TV (They will be expensive) and take it of the rent. 

I buy houses in Columbia Heights - Petworth area with as many bedrooms as possible (I'll turn a living room, a dining room with an egress window, basement rec room, a heated porch, etc. into bedrooms as well.) and rent by the room.  

UmañaR&R heating & cooling was great when I had used him before.