Whenever there is no hot water it always seems to happen at the worst time, such as getting ready for work, family is staying for the weekend, the family dog was skunked and needs a bath. We have come to rely on hot water that when we don’t have it it is end of the world. So what can you do when you discover you have NO HOT WATER!
For starters, make sure it is not just a single valve (faucet) that has no hot water. You do this by turning open the hot side of another faucet. If there is no hot water at least you verified it is a water heater issue. If in fact there is hot water on another valve then the first faucet may be in need of repair. If so, it is possible the bad faucet is on its own hot water supply. There are many homes that have point-of-use under cabinet water heaters for individual faucets. These instant-hot water heaters are used in place of the larger storage tank heaters.
But don’t get your hopes up yet because chances are you don’t have a point-of-use water heater and more than likely it is a storage heater issue. Locate the main water heater. If you don’t know what t is or where it is located then go back a few steps and call a plumber. If you have id’d the heater then there are a few steps to take. One, check to see if the water heater is electric, gas, oil, solar or propane. That’s a lot of choices and your home may have a combination of fuel sources. Most home are equipped with either gas or electric heaters. Mobile homes often have propane or oil. Whatever source you have make sure there is some fuel available. If you have natural gas check to make sure the gas is on to the house (turn on the stove for example.) If your water heater is electric check the breaker box to see if a breaker has tripped, it is usually marked and labeled. If your heater is oil make sure there is fuel in the tank. And is the heater is solar, then I have no clue. Here in cloudy Ohio solar is not an option.
Once you are satisfied with an adequate fuel supply then the next thing to check is the heater itself. A gas heater has a part called a thermocouple. It is a part that controls the automatic gas valve and prevents gas from escaping. It operates by applying heat too one end and the heat opens a gas valve to allow the burner to fire up. A bad thermocouple is very common. Get a new thermocouple.
On an electric water heater there is not much you can do. There are two elements in an electric water heater and if one goes bad the other is not far behind. Replacing the elements is not a hard job but you need a specific socket, usually 1 1/* or 1 1/4″. Plus the fact you are working with 220V of electricity. I don’t recommend you work on it unless you have experience in this area.
On a combustion-type water heater (gas, oil, propane) they require a source of fresh air to keep a flame alive. It is entirely possible for a blockage at the inlet side of the heat chamber or the outlet side. The inlet side is usually at the bottom of a naturally vented water heater. If there is dust and debris around the bottom of the heater it prevents fresh air from getting into the chamber. Then on the exhaust side (the silver pipe above the water heater) could be blocked. Many time I have opened the vent and found a nest of mice or birds clogging the opening.
You may have a power vent water heater. This is one with a motor atop the heater. This motor is a blower that pulls fresh air from the outdoors, through the heat chamber and back out to the outdoors. The power vent heaters are much more sensitive to blockages and will instantly shut off. Troubleshooting a power vent is complicated because these heaters have a microprocessor and a set of ‘dashboard’ lights. If you have a power vent my suggestion is to get the owners manual and follow the troubleshooting instructions. Your instruction manual may be taped to the side of the water heater. If not, jot down the brand, model and serial number and look for the manual online.
You can always call a call a plumber. Coming from a plumber I can attest that most people will call a plumber. These few things above are a few things you might try before calling a $95/hour plumber.