So this place was made into a duplex and they forced a hot water heater into a small closet. Maybe I’m not understanding properly but why is there not a hot water Shutoff valve there? The hot water wasn’t shutting fully off on the tub, so the valve stem likely just needs to be replaced, not hard… quick cheap replacement usually… But when I went to shut off the hot water I found this.
Side note, I also found their was no exhaust vent for the dryer a couple years ago, we had to have someone cut a whole where the exhaust was ran, but just sat up against the exterior wall with no outlet. (Obviously a fire hazard). Shit happens, but am I wrong that a shut off valve should be there?
You should be able to turn off that cold water inlet valve instead. The pressure from the hot water tank comes from the cold water being pushed into it, so just turn off the valve and open a hot water faucet somewhere nearby to release any pressure that has already built up or may get through that crappy valve.
How long can you do that for, it won’t cause issues with the heater without turning off the power?
It shouldn’t cause issues, since the water will remain in the heater without any pressure to push it out, there’s no difference between leaving it sitting with the valve open or closed.
Now, draining the tank could actually cause problems… But there’s not any reason for you to do that for what you’re trying to accomplish.
Turn off the power to the heater before doing any work
As long as there’s water inside the heater it’s fine.