What are some causes that the water heater overflow would be randonly running small amounts of water on the floor? It is only turned to warm.

Do you have an expansion tank on the system? It may have failed.

When the water heats up and expands it can't go anywhere so it blows the pressure relief.

I assume you mean the T&P valve which should only open at 150 psi or 210 degrees. It would be very rare for an expansion tank to cause this since most homes do not even have an expansion tank. If you do not have 150 psi or 210 degree then you have a failing T&P valve. Just replace it with an indentical style valve for about $12 and be sure to use 3 wraps of teflon tape.

I agree with Ballangerb1.... but I would first measure your pressure inside your house. If too high, replace pressure regulartor first. Than, replace T&P valve....

What's the house pressure? This can be checked with a hose bib pressure gage,(see image). The average house pressure runs between 40 and 60 PSI with the norn at 45PSI. Let me know Tom

I guess it's a where you live thing.

Most homes in my area don't have pressure regulators. We do have check valves and expansion tanks. The check valves are required as a back flo preventer. It is also fairly common to find a water pressure of 60-80psi, but it is usually near 60.

Tap the expansion tank with a metal object. You should hear a different sound at the bottom then at the top. If you hear the same sound all the way up you have a ruptured membrane and a faulty tank. Let me know the results. Good luck, Tom

Yep you are correct. One part of my town needs a PRV because incoming pressure run about 90 psi while my end of town is lucky to get 45 psi. Tom is just trying to be sure the house has not developed excessive pressure but I am leaning toward just a bad T&P. Once they open or leak I always replace them because they don't seal like new 100%.