water heater buzzing when running water

Don't want to alarm, but this is something you need to solve. More than once in my 35 years repairing home appliances, I have heard what I would describe as a buzz, that turned out to be a short. It happens when you run the water because that's when the elements kick in. The WH is propane or 120 VAC, so it's not a huge electrical issue. The relief valve is definitely a possibility, also. Just try to get it solved rather than just give up. No one wants an emergence if we can solve before then. hth