One would hope that Flippers were either capable of renovating a home, or employs professionals who know what they are doing. Doing home inspections professionally I have learned that hope really does spring eternal...
This particular house, with the fine front stoop repair, was serviced by Liquid Propane gas (LP). I checked and the furnace and water heater were made to handle LP gas.
Is that important? YES!! Appliances can be made for LP or, if made for natural gas, can be converted for use with it. On remodels it is important that proper appliances be used, or have evidence of conversion kits. LP is compressed and its molecules are smaller and require a much narrower orifice for proper mix and combustion. When LP is used on a natural gas appliance there is too much gas being burned and the result can be disastrous.
An LP appliance will have a sticker that indicates it, or "PROPANE" will be somewhere on the information sticker.
If a conversion kit is used there are similar stickers very visibly placed to so indicate! They are sometimes RED and often include serial numbers.
This is evidence of a proper installation.
In this house I turned on the brand new oven to test it. A moment later flames were licking out of the gaps on each side of the oven! They were three inches high! Despite many photographic attempts the flash drowned out, and made it impossible to capture, these flames, but trust me they are there! The brightness of the light coming from those openings is unusual in itself. And the house began smelling like poorly-combusted propane.
Did this Flipper know to use the correct appliance, or have one converted for LP use? Did he know that this house was serviced with LP gas? Did he understand the difference? I don't know. But I DO know that such ignorance is very dangerous.
My recommendation: If a house has LP and there has been remodeling done, ask for proper documentation that all the gas appliances in the house are so manufactured, or converted for LP use. If not, who knows, one day you may hear that your clients are in the news...