cool water in water heater

Does it work in the gas mode? Did you check to see if the breaker is tripped? Switch it off and back on and wait a while.

by any chance is the by pass valve open .let hot and cold water mix.

What brand water heater? Does it operate on propane? Did you measure for voltage at the element?

Ohms sounds about right.
Multiple possibilities;
Inside switch (if you have one) bad or off
Bad 12 vdc to 120 vac interface relay
Outside switch (on the WH) bad or off
Tripped or bad hi temp cutout
Bad thermostat
Loose or bad wire
Suburban WHs have a junction box on back side. Loose wire connections have been reported there. Don’t know about Atwood.

Very common if you have an outdoor shower and turn it off at the spray end leaving the hot and cold faucets on. That allows the hot and cold to mix.

Does the element get power? Seems like an open circuit. Check if you have a switch in the service area. Or possibly the thermostat (long shot).

People, READ the OP's post. He stated he checked the temp at the Relief Valve. That rules out an outside shower or anything else from the water heater to the interior plumbing. FYI, you ALWAYS check the temp at the Pop OFF valve FIRST when checking for Water Heater heating problems. IF the water is NOT scalding hot out of the Pop Off valve the problem is at the Water heater, no where else. His OHM's are correct. Odds are he has a bad tstat. But, he needs to post Brand and Model number of the Water Heater. Doug

If yo were talking electric.maybe the element it covered with the white ****. take element out and clean it...might work.

Ok finally the weather stayed nice enough to try to tackle this problem with water heater. It's a Suburban SW6 DE and today I removed the switch and that's good.I disconnected the black and white wire to the heating element turn on the power at the switch and no power at the black and white wire. Any help would be appreciated

If there is power coming out of the switch but not at the element, the only thing left is the thermostat/high temp cutoff. They are together as an assembly. The ECO has a reset button you can check first. Page 13 here shows the t-stat.

Well I finished the water heater problem today thanks wnjj that was the problem ...it was the thermostat...on the bad thermostat there is a small thin wire between the two sensors and there was a burn mark on that wire maybe that had something to do with it. Again thanks wnjj.