If its a big cast iron boiler, id consider swapping out for a couple condensing boilers with a 10:1 turn down ratio and install outdoor temperature reset.

.- Tenant agrees to keep the property at a reasonable temperature, leave water connected and leave refrigerator on / cooling.- Tenant pays 1 months rent as a releasing fee.

I work a warehouse job.How money do I need to save up to invest in real estate?

There are 3 older houses that come with the property and one 40x40 metal warehouse.

Turn washer spin speed up to the highest setting because they're unlikely to change it..5 GPM aerator on bathroom faucets1.25 GPM aerator on kitchen faucet1.25 GPM showerhead1.28 gp-flush toilets--I'm only replacing them because they're the horrific 90s toilets that clog CONSTANTLY, as the water savings will literally never pay offNew tub spout diverters because the current ones leak around the edges badlyY-splitter on top load washing machine to connect the washer only to the cold supply (it's not a high-efficiency, so it cleans well at any temperature) Smart thermostat with 74 degrees minimum cooling temp and 71 degrees maximum heating temp until 10 pm, dropping to 68 degrees until 6am Alarms on doors and windows that alert me if either is left open while the heat or AC is onNew windows, because the current ones are single panes in need of heavy maintenance and are already causing problemsPossibly solar screens on two of the windows that get the most light, particularly a west-facing one

They're rated to heat down to certain temperatures so check what those are, but they are a great way to get heat and air.  

We lived in a 3 floor townhouse at one point that had one zone. it was like we were pretending to be Goldilocks with the temperature difference between floors.

I am in the warehouse.

I have the opportunity to buy a 15,000 sq ft warehouse from a failing business.

Start out at room temperature and turn up the heat slowly, he's not going to notice.The worst mistake I made as a novice landlord was to think "Oh my tenants are great", I don't want to scare them away with yearly increases.