When I have a situation with mold, I first eliminate any source of water or moisture. 

So, my floors have been a concern due to moisture and cracking.  

I used a penetrating concrete sealer, then an insulating vapor barrier/underlayment, and on top a floating luxury vinyl plank floor.I also installed a ductless heating/air conditioning system for that space.

Placing them properly as well as resealing when necessary will deter moisture and water issues in the future.

Some parts had turned wavy because of moisture I think?

My only caution with laminate is that moisture/water will damage it...so keep away from wet areas.If you do replace with new carpet, make sure there is a clause in your lease requiring the tenants to have the home professionally cleaned when they leave....or there is a charge to do it for them.Hope this helps!

I havnt seen any water but I am afraid to do anything like carpet until I know if there is moisture.

Having the opportunity to work with or go in together on a deal with someone who's done it before will catapult you forward in terms of your ability to penetrate the market again in the future.Good luck, and keep us updated on your journey!

If you are unsure, you can also use a moisture meter to test the moisture content of the wood.

I’m taking several tools from a black light flashlight to moisture meter to thermal camera to check everything out and smell the smell for myself to see if I can figure it out.The vent stack for the water heater is a straight shot vertical up, and is a solid piece going to the roof, same for the furnace.