If i put 4 water heaters in a 4-plex, then the tenants can pay for the cost of heating the water, but I have to pay for 4 heaters and worry about capex on 4 heaters.

I cleaned it up, installed a new heating system, and sold it for about 50% more than I paid for it after holding for a few years. 

It sat empty for two months and we had to heat it, plow snow for showings, etc...  

The weather can play havoc on your property in cold winter areas.You need to make sure the property has been winterized by having the heating,water heater,pipes,rain gutters,and the like are serviced for winter and fully inspected.Make sure you have a snow removal plan in place like the tenant has to do it or you pay someone to do it on a regular basis.

Im sensitive to her situation but also leery about a winter vacancy complete with heating bills to pay.

Also, always change your unit's HVAC filters or you be going through heat exchangers, evaporator coils, and compressors more often.  

Speaking of electrical, I had about 6 service calls on a rental about the electric heat and AC ... they messed with the unit all kinds of ways but never fixed it.

definitely agree with what the folks have said that market has heated up which has made finding great deals harder to find in the South side of Chicago but they are there!

( sewer line replacement , heating system failure, etc )  you need to have funds available before problems happen 

@Evan Ventura,People here on BP have also successfully used the cheap IKEA countertops (around $75-99 for a piece). at that price they where treated as expendables (one per tenant), and some even reported getting the install time with demo at 2-4 hours.for the other, you need to "waterproof" the common points of water entry:-caulk between the wall and countertop-use varnish on points contacting sink-use good glue near the oven/range since the usual pressure-activated glue does not fare well with heat