Is it necessary to turn off the gas water heater when replacing valves in the basement bathroom, or can I simply close the inlet and outlet valves while lowering the heat for safety?
Asked by Milica Radivojević 
6 months ago
Last Updated: May 31, 2024
I have to swap out some valves in my basement bathroom, which means shutting off the main water and draining the pipes. I’m a bit worried about the gas water heater though. Do you think I absolutely have to turn it off? What if I just close the cold inlet and hot outlet valves to be safe from draining it? Maybe I could also lower the heat for extra caution? I really want to keep things simple and not mess with it too much. Thanks in advance for any advice!
Yeah, the water heater is probably going to be the lowest point anyway. Unless you plan on draining the water heater to get rid of the hot water, you don’t need to worry. If you have a basement bathroom and/or laundry room, just shut off the water supply to the water heater. Turn off the main water supply. Open the taps or shower in the basement bathroom. Turn off the taps for the washing machine. Disconnect the water supplies to the washing machine. Then turn them back on into a bucket, slop sink, floor drain, or washing machine drain…and there you go.
-a plumber
Hey , I appreciate your help! I’m a bit confused though – if I turn off the main water supply and/or the water heater supply, won’t opening the hot taps drain the water heater without refilling it? Would it be a problem to shut off both the inlet and outlet lines to keep the water inside? Or maybe I’m just thinking too much about it.
Hey there, , I think you might be overcomplicating things a bit. Just to clarify, when you turn off the cold water supply to the water heater and run the hot water tap, all you’re doing is releasing the leftover water pressure that’s stuck in the line. If you want to fully drain the water heater, the only way to do so is through the bottom drain!
Your response was super informative and really helpful. I can totally imagine myself in that scenario, and after reading your advice, I’d definitely feel more equipped.
Thanks a bunch
Thank you so much for your support with this project. I feel much more confident now.
You’re welcome! If you ever need assistance, just let me know. Best of luck!
I really appreciate your help!
I close the main water valve in the house and the outlet valve on the heater. I’ve never turned off the gas valve on the heaters.
I usually turn it off for safety reasons. It also depends on how old it is. Just consider if you’ll be able to relight it. Good luck!