Tenant agrees to allow Landlord timely access to premises to do maintenance and repair.Tenant will notify Landlord in a timely manner of any damages or problems as they arise, including damages caused by Tenant, malfunction of appliances or fixtures, and water/moisture leaks and spots.Tenant will care for the premises, keeping them clean and clear of debris.""

His approach to managing his own properties is that he has paid for all his tenants' first time offenses and given them a stern warning that if it occurs again they have to pay 100% of the costs, if the broken/malfunctioning component is their fault their next time.  

@Matthew DeMichele, I agree with Scott that 20k is not a lot to get started in real estate, one system malfunctions and you'll be underwater.

As for Electrical, aluminum wiring is a red flag not seeing it can't be used but it has greater chances of malfunctioning and causing a fire vs copper(aluminum was used more in the Vietnam era but this is just precaution), make sure all electrical work is grounded (you can tell if the receptacle are 2 prong and not 3), Service and Panel size would also need to be adequate if you plan on adding more rooms and circuits(I recommend at least 150 Amps).

I've preferred the Schlage locks in the past because they do not try to power the deadbolt - they simply unlock and the user turns the deadbolt - which leads to longer battery life and less chance of malfunction due to alignment changes in the door (a common attribute of winter with older buildings up here).  

CLERICAL ERROR WAIVER: In the event the Buyer at any time discovers that any of the documents executed in connection with this transaction contain an error caused by clerical mistake, calculation error, computer malfunction, printing error or similar error, all parties agree, upon notice from the Buyer, to re-execute any documents that are necessary to correct such error(s).

Responding to a tenant's notification of a malfunctioning (HVAC) system within 24 hours is reasonable.

2) If my manager does not get involved I feel that I still have to find out what is going on myself by sending the renters a letter to ask them what is going on in the condo, like are they just setting the thermostat too low all day every day or is there something malfunctioning in there. 

Here is what my standard lease that I picked up from the internet and use with my rentals:(2) Repairs that Tenant will Pay Entirely: Tenant will pay Landlord or any contractor Landlorddirects Tenant to pay the entire cost to repair:(a) a condition caused by Tenant, an occupant, a member of Tenant’s family, or a guest orinvitee of Tenant (a failure to timely report an item in need of repair or the failure toproperly maintain an item may cause damage for which Tenant may be responsible);......Appears it includes failure to timely report as a cause to make tenant pay.I also have a Maintenance Addendum that I got online that includes: Immediately notify Agent of any evidence of a water leak or excessive moisture or standing waterImmediately notify Agent of the presence of mold, mildew, or similar growth in the Premises after you have attempted to remove it using common household cleaning solutions or anti-microbial productsImmediately notify Agent of any malfunction of any part of the heating, ventilation, air conditioning, plumbing, or laundry systemsImmediately notify Agent of any inoperable doors or windowsOn looking at it now, it does not state what the remediation would be if the tenant does not adhere to this. 

If you provide the mower, you can set yourself up to be responsible for maintenance and liability if it malfunctions.