Takagi T-H3-DV-N Condensing High Efficiency Natural Gas Indoor Tankless Water Heater, 10-Gallon Per Minute, 199,000 BTU

I installed this unit a couple of weeks ago, and it's been working like a charm. It was pretty easy to install, but I'm a pretty handy guy, so I don't know how easy it would be for a regular joe. Its flow rate of 10gpm assumes you're not heating the water to 131 degrees, which I am. The higher the temperature set point, the less throughput because it takes longer to get the water up to temperature. I originally installed a Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas, with a rated GPM of 6, but the flow was so low at 131 degrees (2.9) that it took almost 20 minutes to fill the tub for a bath. This unit, even at 131 degrees, has a flow rate undistinguishable from the 50-gallon tank water heater it replaced. Of course, it cost twice as much as the T-KJr2, so that makes sense.This is a condensing unit, which means it puts out water that must be drained appropriately. If you don't have a drain nearby, that's going to be a problem. The condensate is because this unit improves efficiency with a secondary heat exchanger, which extracts what otherwise would be waste heat exiting up the flu. Instead those hot gasses are used to help heat the water, and the much cooler gas is then vented up the flu. This cooling of the gasses causes water to condense out of those gasses; thus the need for a drain tube.How much heat does this save? Well, the vent for the T-KJr2 was too hot to touch when the unit was in operation; with this unit the vent is barely warm to the touch. In fact, instead of having to use double-walled stainless steel venting, I was able to use 3" PVC tubing.If you have very hard water, don't expect a trouble-free existence with any tankless unit. They are very sensitive to scale buildup (as is any water heater, but tankless units particularly so). My house is equipped with a Culligan whole-house water softener, but in the interest of overkill, I installed two filters (DuPont WFPF13003B Universal Whole House 15,000-Gallon Water Filtration System) upstream of the water softener. So before the water gets to the water heater, it passes through a sediment filter, a carbon filter, and then a water softener. According to my HVAC guy, this will greatly extend the life of the water heater. (The two filters also means I can now drink water right out of the tap, anywhere in the house, without that nasty chlorine taste.)In short, I highly recommend this unit. Plus, it looks really cool!

I purchased this unit in Oct of 2016. This is the 3rd Takagi I have owned. The first had an issue with the heat exchanger due to the intake air coming from a utility room as well as sensor issue. The second also had a heat exchanger issue even though it was installed correctly. Takagi supplied a new heat exchanger that I repaired and kept as a backup unit. This new unit has a commercial grade heat exchanger with much tougher materials and has been running flawlessly so far. The key to these is buy a larger unit than you think you need and make sure it's installed and maintained properly. There is nothing like endless hot showers!

Originally we liked this. But it's dead within the first year. The pipes on the heat exchanger broke. There are U-curves that allow the water to flow back and forth over the flames in the heat exchanger. The welds were not done properly on one side and they started leaking. Unfortunately, the heat exchanger is on the top of the device... the electric device. So the water started frying things. We learned about this after resetting it a couple times. At first it was weird. When it became frequent, we opened it up and saw water inside from the breaking pipes. Called tech support and they had me rip it apart to remove the burner. In doing so, the pipes broke more. Didn't figure this out until I had re-assembled the thing and turned it on again. The tech support offered to send out a new heat exchanger for free. They blamed 'bad water' on the welds failing in 10 months of use and are giving us the part... we just have to pay shipping. So a year in, I have to rebuild our water heater. And they mentioned at the end of the call that since the water will have damaged the other parts, be sure to call when they fail so they can send out those replacements... if I pay shipping.This isn't 'goodwill'. They know they have a defect in their heat exchangers. And now that defect has trashed the other components. We are supposed to be without hot water for days while they ship us parts and more parts to replace the parts the first parts broke?Forget it. Buy your water heater locally. This one is a kit that you'll have to keep rebuilding with more parts. I wish I could give it no stars. We have spent about $100/month for this ($1000 to buy it and 10 months of use before the pipes broke).Don't buy anything online that you can't live without for a day. We live up North. We can't go without hot water in the winter. It's just not worth it to freeze your butt off in the shower so you can save a few bucks. We love Amazon. But Takagi's service and their product are junk.

Very good product!We are very happy with our new tankless water heater.