Jake Romano explains that “water heaters are essentially sealed containers that handle heat, water and steam. You need pressure relief valves to deal with the high pressure and serious problems. A water heater without a working discharge valve can literally explode.” Some signs of high pressure to look out for include a leaking discharge valve, popping and popping noises, or water discoloration (via Three Two Home). All of these could indicate that your water heater has reached its pressure limits.
Like a tea kettle, a water heater needs a valve to allow steam and pressure to escape. If the valve does not work properly, there is a high risk of rupture, leakage or even an explosion. To avoid this, Romano says, “Test your pressure valve once or twice a year. Place a bucket under the pressure valve, open and close it. The water should start and stop flowing. If it doesn’t perform as described, you must replace the pressure relief valve immediately.” You can easily replace the pressure relief valve yourself, but if you want to be extra careful it’s never a bad idea to call your plumber or water heater company.