For plumbing/HVAC I use Mat's Mechanical exclusively (water heaters, furnace trouble shooting, etc). 

The hot water heater was on it's last legs.

. $1500 Total.I pay for water and trash, should cash flow about $500 a month after expenses.My strategy is to fully rehab both units, replace some damaged hardwood, refinish it all, upstairs bath and kitchen were totally gutted, and will be refinished and tiled.

If you want to create a muddy mess let the water run in the bath tub for weeks until you flood / fill the septic tank and the ground turns soggy.  

The tennants pay for their own water and utilities so expenses would be low.

One thing we did discover is (this property doesn’t have a basement it’s on a slab), because of the pet urine soaking into the concrete after cleaning, bleaching… we sealed it with Kilz oil based sealer to lock in/out the odors and ran my Ozone machine for a month to help with the smell.The Bear Paint distributor for Home Depot said we should have used water based Kilz and not oil based.

Taxes 3172they both have their own water and utilitiesSide 1 has not been renovated in 20 years so i would have to change the carpetside 2 has been renovated and should have no problem bring in the normal rent.The current going rent around the area on average is 850 with some renting around 900.Should i pull the trigger?

Here are the details on the propertyJanesville, WI4 unit; 1b/1b eachAsking Price: $100k (Also assessed at 100k)Rent: $2300 totalLandlord Costs (Gas, Water, lawn/snow): $303PITI: $832 (after Refi with loan value 98k)Vac, Maint, CapEx, Mgmt: (8,10,8,8) $782Repairs: 17 yrs SMOKE DAMAGE; new roof; new windows; Kitchen updating - Estimated: $25kMy only comp is another seller with 4 unit; 3 units with 1 bed, 1 bath; 1 efficiency; who said they were putting on market for $160k (though assessed at $115k).

My concern is how to research the extent of the liability that comes with houses.From what I have read, the secondary liens are removed at auction and all I need to worry about is back local taxes, IRS taxes and water/sewer bills.  

You should not get too much competition from the typical first time home buyers because they get scared away by the large initial repair bill, evidence of water damage or mold, missing appliances, broken stuff, non-home-warrantied HVAC units, etc..