I have been looking at many connected devices that let you know, if there is a leak or if the sump pump is malfunctioning. 

He missed that some electrical outlets were malfunctioning, the plumbing in the shower was not working properly, the power box was old and outdated, the AC was not working, etc. - Don't be afraid to make sure everything works well and if it doesn't, don't be afraid to ask them to fix it or ask the seller for a credit.

I like the idea of them but I have found that many LEDs burn out or malfunction over time just the same as regular bulbs, which makes me a bit hesitant to install them.

Malfunctioning appliances, defective TV, broken washer/dryer are all their problem.

I would let her know you are willing to come by to see if there is a malfunction(assuming they are interconnected). 

I won't go into all of them, but the primary thing was that our kitchen cabinets were basically falling off the wall, the dishwasher stopped working after using it 3 times and the P-trap under the sink was malfunctioning, causing a constant water drip and massive hole under the sink - which they had covered up with a shelf and cleaning supplies.

I did consult with an attorney and they indicated that central A/C is not required in the state of California.I read through the lease and there is no clause that the tenant can leave due to a malfunctioning appliance or A/C. 

Ok, so here's some info I have come across, the building in February of this year had a wiring malfunction that shut the doctors office down for a few days to be re-wired.  

Under paragraph 11, titled Maintenance, it says:“Tenant shall immediately notify Landlord, in writing, of any problem, malfunction or damage with any item on the property.

It will be best to have the outside expert opinion on file as to what caused the malfunction.