Answer

hi...
this is a little puzzling.. really the only things that could be causing the issue are the bypass valves or check valve. since you removed the check valve, we know its now that, and you have checked the position of the bypasses. only thing really could be the bypass valve is bad. even though the handle may move, the valve inside isnt.
do you get any water at all, cold or otherwise to the hot faucets or is there nothing?
i would first check at the pop off valve make sure you have pressure in the tank and water is at least getting to it properly.
if that checks out ok, i would go back behind the heater and see if you can crack the line at the bypass valve, see if your getting anything through the valve. id suspect a bad valve, cracking the line will show you if you have pressure.
unless it is comming out of a low point drain, this is really the only place the fault can be. check the lines at the valves and let me know...