I have tenants that complained about the electric bill .  

The numbers -Based on 4 other comps within the same building complex all the same bed/bath & square footage that have sold from 70,000-80,000 within the last 3-6 monthsAsking Price- 55,000Purchase Price- 50,000 Market Value- 70,000Water,sewer,gas,garbage- included in HOA & electric paid by tenantTotal operating expenses:          $457.67Mortgage expenses:     $185.25Vacancy:$40.00Repairs:$40.00CapEx:$40.00HOA:$176.00Insurance:$60.00P&I:$185.25Property Taxes:$91.67Misc:$10.00Monthly Income:$800.00Monthly Expenses:$642.91Monthly Cashflow:$157.09Pro Forma Cap Rate:8.22%NOI:$4,108.00Total Cash Needed:$10,000.00Cash on Cash ROI:18.85%Purchase Cap Rate:8.22%

The latest example came from a text saying that he fixed an electrical issue and was taking $150 off rent.

You are inviting potential water, mold, bad electrical problems, etc. 

I think, for your first investment property, given your experience and time or lack thereof, just go with a newer home, or one that has been renovated well, so you won't have to replace plumbing or electrical or roofs or finishes or fixtures etc. 

Electric is the big expense, but is usually paid by the tenant.

I've calculated the costs but just realized I forgot about water, heat, electricity.

Use a schedule of values (where you set a dollar amount for line items of labor and materials being performed e.g. rough plumbing, rough electrical, foundation, etc.).

Once we get interested in a property and before we make an offer, we require the seller to give us the following: last 12 months of all landlord paid bills (electric, gas, water, etc), tax statements (although these can be confirmed on the web), and all leases.We review all these and run our own analysis.

Also you as far as your heating goes, you can go to Lowes or Home Depot and buy baseboard electric heaters.