Your water heater is one of the most expensive components of your plumbing system. It costs a lot of money to buy and it costs more money to operate. If your hot water heater is not working properly, it can make your life miserable. Unless you really like cold showers, it’s a big deal when your hot water heater has problems.
When to call a plumber
This is a good time to talk a bit about when it’s appropriate for you to fix things yourself and when you should probably call a plumber. Water heater problems are a good example of when this choice is important.
If your water heater is leaking, unlike the pipes connected to it, this probably means that it needs to be replaced. It is virtually impossible to repair a leaking water heater. If you can’t confidently say you know how to install a water heater, you really need to be careful.
Replacing a water heater raises a lot of safety concerns and it takes some pretty technical skills to get the job done right. It’s usually best to call a licensed plumber if yours needs to be replaced. Licensed plumbers know how to install a gas water heater without creating a potentially dangerous situation (and how to install an electric water heater without getting electrocuted in the process).
You can do it!
On the other hand, if you have a water heater that doesn’t leak and you don’t have hot water, you can often fix it yourself without calling a plumber. You don’t need any technical skills to learn how to troubleshoot your water heater, just a little common sense and patience.
The first piece of good news is that although the trend is toward cheaper water heaters, the basic operation and controls haven’t changed much over the years. So some basic knowledge will allow you to troubleshoot water heaters of almost any age or manufacturer.
Gas or electricity?
There are two main types of storage water heaters (we won’t get into tankless models here): gas and electric. This indicates what type of energy source is used to heat the water.
gas water heaters
Gas water heaters use natural gas (and sometimes LP) to power a burner which in turn heats the water like a pot on the stove. They have only a few components that control whether or not you have hot water.
The first thing to check if you have a gas water heater and you don’t have hot water is whether or not you have gas. I know it sounds silly, but I have gone to many a home only to find that the gas had been shut off for one reason or another. If you have a gas stove, see if it works. If not, check your meter to make sure it’s on.
If you have gas, the next step is to check your pilot flame and, if it’s not there, try to light it. Lighting instructions are usually right on the water heater. If the gas has been shut off, it may take a while for the air to bleed out and for the gas to reach the pilot, so be patient.
the thermocouple
If your pilot doesn’t light, or doesn’t stay lit, the thermocouple may be the problem. This looks like a copper wire coming out of the control box on the front of the water heater and down to where the pilot light should be. It has an enlarged tip at the pilot end.
The thermocouple is placed with its enlarged end in the pilot flame. This heat from the pilot flame causes a small electrical signal to be sent to the control valve, telling the control valve that a flame is present, so it is okay to let gas through to the main burner when the thermostat calls for heat. . You can change a thermocouple on most water heaters with just a small adjustable wrench. Just make sure the end of the bulb is sitting securely in the pilot flame. You can get a new thermocouple at most hardware stores for less than $20. This will usually correct a problem with the pilot light.
On newer water heaters, the combustion chamber may be sealed. If you have one of these, there will usually be a small inspection window that you can look through to check the pilot. You may need to call the manufacturer for a complete pilot assembly and a new cover seal to repair these models, but the procedure remains largely the same once you get the parts. These parts are usually covered by the manufacturer’s warranty.
gas control valve
If you are sure you have gas and replacing the thermocouple doesn’t fix the problem, the gas control valve is the only thing left to check. This is a pretty major repair, so if you’re not very comfortable working with gas connections, you can call a licensed plumber for this.
electric water heaters
Electric water heaters use, you guessed it, electricity to heat water. If your electric water heater is not working, the first thing you should do is check your circuit breaker or fuse box. Many electric water heaters also have a separate disconnect box on the water heater, check this too.
If you are sure you have power, the problem is either the heating elements or the thermostats. Most electric water heaters have two of each, top and bottom. To check or replace a water heater element, you will need to turn off the switch serving the water heater circuit and remove the access cover from the water heater. At this point, you might get lucky and find the easiest way to repair an electric water heater.
the reset button
Many thermostats have a reset button that can sometimes be pressed to reset the circuit and get the water heater working again. To find it, you may need to carefully remove any insulation covering the thermostat. If the reset button has been triggered, you should be able to hear and feel a definite click when you press it. If you think it’s tripped, put everything back together, turn on the power, and check for hot water in about an hour.
If the thermostat cannot be reset, you will need a voltage meter or continuity tester before proceeding. There isn’t room in an article to cover electrical diagnostics, but you can perform a simple continuity check on the elements to make sure they form a complete circuit.
heating elements
First, make sure there is no power to the water heater! Then locate the heating elements. The elements will either have two wires attached to each and will either have a large hex nut where they either bolt to the tank or attach to the tank with a bracket and usually 4 bolts. After confirming that the water heater is cut out, remove the 2 wires from the element and check for continuity. If there is no intact circuit between the two terminals of the element, it is bad.
If one or both elements are damaged, it’s probably a good idea to replace them both. You will need to turn off the water and drain the water heater to replace the elements. If they are the hex nut style, you may need a special socket. You can usually find these tools where you buy the items. Make sure the water heater is completely filled and all air has been purged from the system before restarting or you will ruin the new elements by “burning dry”.
thermostats
If the elements are fine and do not need to be replaced, it is probably the thermostats. It is a good idea to replace both thermostats if there are two, they are quite inexpensive. Simply remove the cables, connect the new one just like the old one, replace the access plate, and turn the power back on. You should have hot water in about an hour.
Know your limitations!
Learning how to troubleshoot water heater problems can be fairly simple, but you need to understand and be comfortable working with gas and electric. Either one can literally kill you if you don’t observe proper safety precautions. If you are unqualified or unsure about something, it is better to be safe than sorry.