Ran out of hot water and went to check out the water heater. Testing water heater thermostats is important in locating water heater problems. Hot water cylinder thermostats. Set the multi-meter to measure ohms of resistance. There is a range for optimal temperatures on water heater thermostats. Locate the access panels and carefully remove them. After some time has passed, you should feel a difference in the water temperature coming from the faucet. How to Test and Replace a Water Heater Thermostat. Wire nuts are often used to connect the thermostat to the system wires. heat up the top portion of the water to the setting of the thermostat. Use the water heater tester to check terminals #1 and #2 (the lower set). Turn the temperature to its highest setting on the upper element. If I Don’t Want To Fix It Myself, How Much Will It Cost? Now, Go back to terminal one AND the red wire on the lower heating element. Sometimes, however, we need a little help understanding how certain things work. Usually, this is higher than 170 F. You can press the reset button and the water heater will be ready to use again. In many cases, there is more than one thermostat on a water heater. The main thermostat with the high limit switch attached is at the top. Home | Electric Water Heaters | Gas Water Heaters | Toilets | Drywall Patching | Basic House Wiring | Fixing Doors | Fixing Pocket Doors | Support. For reference, when touching water that is 120F, it requires over 5 minutes to produce a burn. This ensures the lower element will activate first, and the water will heat from the bottom to the top. You know when your shower spits ice cubes instead of hot water that it's time to replace the thermostat for your water heater. When it goes bad you don't have any hot water at all. There’s a Leak. No light, then the bottom thermostat is bad. Known for their nonstick nature, high-performance Calphalon cookware can be a lifesaver in the kitchen. Locate the breaker inside the panel box labeled “water heater” or “hot water” and turn the breaker off. The average price to have someone replace the hot water heater thermostat is between $100 and $300. Is the upper element good? Setting the temperature of the thermostat is easy, but ensuring you shut the power off is always Step Number 1! Most water heaters that store more than 30 gallons come with two thermostats (one for each element), and two heating elements. However, after the meal has been completed, they need to be properly cared for in order to... How To Fix A Slippery Tub (3 Ways To Do It!). But first, make sure the power is off. In the absence of such, a technical manual or parts supplier will require referencing. Make sure that the power is off. Set the body of the multimeter on the ground at the base of the water heater. You want to use the water heater tester to check terminals #1 and #2 on the upper element (this will be the lower set of #1 and #2 terminals). Switch off the power breaker that powers the hot water At the bottom of the water tank, remove the water metal to reveal the thermostat of the water heater. We are talking about process of elimination here. Where hot water is stored in a cylinder and heated by a separate boiler, a thermostat is required to avoid the cylinder being overheated. With a couple of tools, this is a fairly quick and easy test. We are going to get into a weird area here. Place the leads from your multi-meter across the terminals at the top of the thermostat pictured above. These water heaters often have a "non-simultaneous" design, which means only one element is on at any given time. Check whether the thermostat is now open. Once the heating element at the bottom turns on, the water in the lower half of the tank heats up. Then it allows power to go to the lower element. Remove the thermostat from boiling water²: 2.1. if the thermostat returns t… The water at the uppermost half of the tank is now hot. To control the water temperature, we need a thermostat. A good thermostat should start opening up when placed in hot water. Simply mark the current temperature setting on the water heater, adjust the temperature up or down, then wait. High voltage thermostats are often built into the wall and typically have two to four thick wires coming out of the thermostat. All electric water heaters have a minimum of one primary heating element used for heating up the water, a thermostat for controlling the temperature, and a high limit switch to save the entire unit from high temperatures. You want to use the water heater tester to check terminals #1 and #2 on the upper element (this will be the lower set of #1 and #2 terminals). Do you have power to the elements and thermostats? There’s nothing quite like relaxing at the end of a long day with a soak in a tub. In the electric water heater and thermostat wiring series, we will be showing the continuous i.e. Found the thermostat was burnt up! The easiest way to test a water heater thermostat is the ‘set and observe’ method. What! Collection of wiring diagram for hot water heater thermostat. 1 Only the models listed in the table above can control hot water. Meaning that only one element heats at a time. See 'Testing Electric Water Heater Elements' for more information. What does that mean? No light, time for a new thermostat. Unless it happens, the thermostat has defected. First, turn the power off to the water heater at the circuit breaker. As the thermostat at the top reaches max temperature, power is redirected toward the thermostat at the bottom. Turn it until it clicks off. The lower thermostat switch will close and heat up the bottom portion of the tank until the water is heated to the setting of that thermostat. Remove the wire nuts to access the water heater supply wires, which will lead directly in to the water heater cabinet. Or, maybe you prefer to wake up in the morning with a nice shower in a combo shower/bathtub. Check the thermostat to see if it has a plastic cover. Typically found on older systems, although these can still be purchased for new systems. ), link to How To Fix A Slippery Tub (3 Ways To Do It! The thermostats are less likely to be at fault than the elements. Once you test it, you can get it fixed or fix it yourself. The easiest way to test a water heater thermostat is the ‘set and observe’ method. If you get the reading of 240V on terminal 1 and terminal 3 then the power is on but if you get no readings then the power is off. Are water heater thermostats interchangeable? You will use the thermostat to get water heated to the right temperature for different purposes. We all enjoy the conveniences of our homes. Thermostat Overview Robertshaw ST Series Water Heater Thermostats are designed for the storage tank water … To check the lower thermostat you need the upper thermostat turned off. If your water heater has plastic and insulation cover pull them out Ensure the power is off with a non-contact voltage detector Follow the steps below: Testing your water heater’s upper thermostat: Shutdown the power on your water heater. Locate the screws that hold the electric access panel to the water heater. Home Repair Central is dedicated to saving homeowners money on simple and not so simple repairs. Remove the insulation underneath as well. The first of which is often how much money it cost to fix the problem. When the upper element works and the lower one does not you have a low supply of hot water. Test 2: Connect the multimeter pin ends on point C & D, as shown in the picture below. Either way, the time... Why Do We Need a Thermostat on a Water Heater? Touch one meter lead to the top screw and the other lead to the metal body of the water heater. Thermostats for the hot water heater are units that monitor and set the heat level of the hot water that leaves the tank. The water is not heating? Benjamin is a proud homeowner who loves to write about DIY projects and home improvement projects. Step 1. Is the water heater element testing thing confusing or what? Head to your circuit board and turn off the water heater’s breaker. Showering, washing dishes, and doing laundry are a few examples. For thermostats on Gas Hot Water Heaters you will need to see the article 'Gas Water Heater Thermostats' for more information. Begin by turning the breaker inside the breaker panel of water heater off. Most of the time, the thermostats get some interest when you have too little hot water or no hot water. Test Procedure for an Electric Water Heater Element. 00 Next you need to check the contacts that control the lower element. But let’s think about what’s happening in the tank at the lower half. After some time has passed, you should feel a difference in the water temperature coming from the faucet. I have never heard of a thermostat burning up like that. Heat up a pot of water to the stamped temperature on the thermostat and use a pair of pliers to hold it under. Likewise, take the second prong and hold it to the center of the water heater element's second screw. Now the entire tank of water should be hot. The reading should be between 110 and 120 volts. Repeat the same test with the red wire. When the thermostat at the bottom reaches its set temperature, the power is stopped, and so is the heating process. If you’re getting hot water but it’s not hot enough, then it likely means that the lower thermostat has gone bad. They are mounted on the outside and rest inside a small bracket so that the element is flush with the outside of the water heater tank. Use your safety glove and goggles while removing the insulation. If your thermostat is faulty, here’s how to fix it yourself. A wiring diagram is a simplified standard pictorial representation of an electrical circuit. Move to the thermostat terminals and check if it is supplied with power. Non-simultaneous will only have a 30 amp breaker. The upper thermostat has two functions. Most electric hot water heaters are non-simultaneous operation. When you discover that the hot water is no longer flowing into your faucets, many questions begin popping up. However, when water starts out hot and then gets cold, it is probably the thermostat at the bottom that is damaged. This includes the cost of having it installed with a technician. 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