Texas heat in the 100s is no joke and a judge will not be nice about you NOT fixing it.

I think also, depending on how hot it is there it could be a + or - as I believe it absorbs heat as well.

My only thought is the common element over 3 years is the owner. 

what it sounds like you are asking is illegal in many ways, section 8 laws, local laws, duel contract laws that conflict, there always has been also those out there looking to catch you breaking them,  avoid it, dont offer it, dont entertain it, there is leeway up if the tenant meets certain conditions, say need 1 floor rental, if not rent may be inflated over realistic market, which is what rented at not listed at, keeping in mind sec 8 market rents also include utilities paid, you can usually reach by email fastest, they have set chart, heat type, neighborhood etc, more than listings found online

There is a common misconception about deleading cost and how it can be done.It varies from situation to situation, it could be as simply as covering hazardous element with some plywood or metal, or it could be some replacement doors/windows and making paint intact.

Each of these elements can impact the overall terms, so it really depends on your specific scenario.

But all well maintained with central heat and air.  5 of the 7 were vacant.

Yea I think ill need to get a plumber over, Someone is suggesting that it is a heat tracer.

I am wondering since no one has asked , is the unit a heat pump or a Air conditioner . 

Chicago winters can be harsh, so we're curious if anyone has had a good experience using a heat pump with an ancillary heat strip for those extremely cold days when the heat pump can't keep up.