I decided to call in a team of professional plumbers to help me along my way, and it made an incredible difference. When the second person turns the water on, the water is warm, but then turns cold before the tankless kicks in and delivers hot water again. Tired of cold showers? One of the options I'm considering is a gas powered tankless. The ‘cold Water Sandwich’ is a phenomenon that is common to most tankless water heater systems. Tankless Water Heaters and the Cold Water Sandwich. The toilets didn't flush properly, and there appeared to be a few issues with the sinks, but other than that the entire place was top-notch. Bosch manufactures a line of tankless water heaters. Choose a tankless water heater that has a delayed shut-off feature. The water heater will not freeze when the outside air temperature is as cold as -22°F (-30°C) for indoor models or as cold as -4°F (-20°C) for outdoor models, when protected from direct wind exposure. A cold water sandwich effect refers to the phenomenon where the water from a heater is warm for first few minutes, then there is a burst of cold water, and then the water quickly returns to being warm again. Unlike a tank heater which holds a supply of hot water that is delivered upon demand until the tank is empty, a tankless heater only heats the water as you are using it. Tankless water heaters are generally low maintenance and very efficient, but problems can still occur. I asked about the cold water sandwich effect I'd heard about, and the sales lady told me it's not a problem if the water heater is sized properly. What is the cold water sandwich effect? I was given a quote on a Rinnai RU180. Tankless water heater considered as a most modern heating device to supply continuous hot water flow. A cold water sandwich is when hot water is coming from the tap and then it is suddenly interrupted by a momentary flow of cold water, followed by the continuation of hot water flow. Part of the issue is that the hot water from a tankless heater isn't really instant. One common complaint is the "cold water sandwich." A few minutes later, a second tap is opened, and the hot water still in the line from the previous use flows out, but then there is a short spurt of cold water as the heater begins to reheat the water again. Tankless Water Heaters and the Cold Water Sandwich. This can be caused by: A dirty water filter on the cold water inlet. Cold water sandwich or hot water temperature fluctuates. Should I trust this answer? This is a common phenomenon with tankless water heaters. The heating element is covered under warranty for a period of five years. This list includes some of the more common problems that people have with tankless hot water heaters, but it is not all inclusive. A lot of different tankless water heater problems could cause you to lose hot water completely. Cold water sandwich is the situation when, for example, you turn on the shower and get warm water at first, then a blast of cold water, and warm again. All Tankless Models Stiebel Eltron tankless water heaters are designed for a very long service life. Contact a tankless water heater repair service for more assistance. This occurs because the tankless water heater doesn’t store hot water as the old tank models do. 1 June 2020 Categories: , Blog. I have a Navien NCB 240 water heater. The safety standards developed to insure the safe operation of water heaters require a delay in the ignition sequence of all gas water heaters. A Rinnai tankless water heater features built-in freeze protection. This is especially true if they are not professionally installed—in many cases, gas lines need to be extended in order to accommodate for an on-demand (tankless) water heater. All Rights Reserved. The stakes are great when commercial property owne …, Commercial property owners face many risks when it …, Many homeowners do not know how to classify home r …, No matter how long you've lived in your house, at …, Maintaining your sewer line is a vital step in kee …, 1 June 2020 I am getting the cold sandwich in all our showers/faucest facets* Gas im not sure ... My Navien tankless hot water heater goes hot and cold in the shower. It can also help to put in additional water heaters if you frequently have several taps running at once. The water that enters the heater en route to your faucet is cold. Cold weather can be a problem for tankless water heaters. What is the cold water sandwich effect? Mario. A tankless water heater provides an endless supply of hot water and reduces energy costs. A cold water sandwich occurs when intermittent use of hot water causes you to feel an initial surge of hot water, followed by cold water, which quickly turns hot again. With so many wires and small parts, tankless hot water heaters can have a long list of possible problems. Mainly the internal orifices for the water flow are clogged due to the use of hard water. Since some of the water will end up trapped in the line once you turn off the tap, it makes sense that there would be a lull in heating if you were to reopen the tap or a second tap shortly after the first usage. The heater remains off until you turn on the hot water. So, by knowing this, We recommend the Flow-Aide System According to this, when you turn on the heater, you receive a warm gush of water initially, then a small amount of cold water, and then hot water again. It’s warm water roulette! How to Troubleshoot Tankless Water Heater Problems. I'm looking at replacing my water heater (a 65 gal. Rinnai™, a maker of tankless water heaters explains the cold water sandwich effect as follows: "The term “cold water sandwich effect” is a term that is used to describe the introduction of cold water into the hot water supply line during frequent on/off operation of an instantaneous water heater. Since there is no reservoir of hot water (because water is heated on demand), the water in the pipes between your tankless water heater and your shower may still be warm from a previous use; whereas water coming into the water heater is quite cold. A gas water heater heats up faster than an electric water heater, so you can minimize the cold water sandwich problem. When I purchased a business building and started to inspect each floor, I realized that there seemed to be some plumbing problems. If the sandwich isn't acceptable, then another option is to have a tankless repair service install a small buffer tank. It should be noted that the cold water sandwich effect cannot be removed completely from tankless style water heaters. This blog is all about choosing better plumbers for your business and following their advice. With a gas water heater, the most common problem is that the burner is clogged, resulting in partial heating of the burner or sometimes there is no flame at all, and the entire burner remains unheated.. One of the big selling points for a tankless hot water heater is the idea of hot water on demand. The sandwich simply occurs when the cold water flow is trapped in the lines between two heat cycles.  Categories: , Blog. The Biggest Problems with Tankless Hot Water Heaters ... That, is a cold-water sandwich and can be highly annoying. Cold-water sandwich Definitely click that link since there is even a handy calculator to help you zero in on the right size based on your groundwater temperature. A cold water sandwich is a fun plumbing term for when the water in your house runs hot then cold then hot again. The following guide can help you better understand this problem, as well as provide ways to alleviate it. Install a small reserve tank (although this somewhat defeats the purpose of a tankless system), Use multiple point-of-use tankless systems to reduce the time lag until you have freshly heated water. Tankless water heaters are a great investment for your home or office. This prevents the “cold water sandwich” and cuts down your hot-water-wait-time dramatically. You can avoid inconvenience from a cold water sandwich by practicing a few techniques. Due to the way that tankless heaters work, any heater can produce the sandwich effect. At this point the heater turns on and begins warming the water as it heads to your faucet. Master Plumber. You must have both power and gas run to the unit. So when the ground water gets colder in winter, the electric tankless water heater may not give you the “endless” hot water you’re expecting. “I’m not getting any hot water from my tankless water heater.” The problem behind the complaint? Not only are they highly efficient, but they can also save you money by heating water only on-demand. It is also known as an energy efficient ‘green' alternative to tank water heater. ... 28/yrs res,com,repair,Universal HVAC Tech. How to Repair a Gas Tankless Water Heater. Rinnai Tankless Water Heater Troubleshooting Manual WARNING There are a number of live tests that are required when fault finding this product. We appreciate your support. Here are six of the most common problems and maintenance concerns for tankless water heaters. Actual life expectancy will vary with water quality and use. Most manufacturers are setting up electronic … The flow from the tankless heater goes through the buffer tank before flowing out of the faucet, so the heated buffer water ensures there is no flow of cold water. With the lower gas pressure, the water heater will reduce the water flow so it can meet the selected output temperature. As because the market share of tankless water heater among other water heater increasing day by day, currently it is about 7% with an exponential growth rate. All other parts are covered under a one-year warranty. This is a problem rarely seen in traditional tank-style water heaters but one you can avoid with regular water heater … Extreme care should be used at all times to avoid contact with energized components inside the furnace. But electric tankless water heaters, like electric tank water heaters, struggle to heat water quickly. These are five gallon tanks that hold heated water. We try to answer tankless water heater failures which in many cases can be solved at home. The so-called cold water sandwich effect is most pronounced with tankless water heaters.