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T-H3M-DV-N High Efficiency Indoor Tankless Condensing Water Heater (NG)
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T-H3M-DV-N has been discontinued
Discontinued April 23, 2026
This product was discontinued by the manufacturer.
MANUALS (6)
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Product Highlights
–
Natural Gas
Indoor Only
Direct Vent
Yes
22.875" Height
13-7/8" Width
Description
–
The Takagi brand has been discontinued by the manufacturer as of December 31, 2025. Suggested replacement units will be available on our website and replacement parts will continue to be available as supplies last. If you'd like any further assistance, please contact our customer service team.
Rebates:
You may be eligible for rebates from your local utility company and state. Search your zip code in the link below for information about rebate programs that apply to you.Takagi Rebate Center
Overview:
The T-H3M-DV-N is a new breed of tankless for smaller spaces. This model also uses existing 1/2" gas supply lines and inexpensive PVC venting to lower installation costs.
The T-H3M supplies hot water to domestic hot water systems (directly or indirectly) which can be used with storage tanks, recirculation systems, and/or domestic & heating applications.
The T-H3M is a high efficient, condensing tankless water heater perfect for residential applications. With gas inputs of 120,000 BTU, the T-H3M can produce enough hot water for two bathrooms in warmer climates or 1.5 baths in colder climates.
- ThermoDrain's can improve the performance and lifespan of all Hot Water Heaters, Heat Pump, Tankless and Tank.
- This unit is NOT approved for installation in Manufacture Homes and is not suitable for space heating applications only.
- ENERGY STAR® qualified
- 15-year limited heat exchanger, 5 yrs limited parts Residential use
- Energy Factor of 0.93 for Natural Gas
- Primary heat exchanger utilizes HRS35 commercial-grade copper alloy for 25 times better heat transfer than stainless steel
- Secondary heat exchanger utilizes 316L stainless steel for better corrosion resistance
- Complies with Ultra-Low NOx regulations of less than 14 ng/J (<20ppm)
- Integrated controls and power cord as standard features
- Venting with Schedule 40 PVC, CPVC, PP, Category III stainless steel
- Safety features include freeze, overheat, surge protection, and troubleshooting diagnostic codes
Specs
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| Energy Factor: | 0.93 |
|---|---|
| Inlet Gas Pressure: | 5.0-10.5"W.C. |
| Product Type: | Tankless Heater |
| BTU (Max): | 120000 |
| BTU (Min): | 15000 |
| Application: | Residential 2-3 Showers |
| Fuel Type: | Natural Gas |
| Vent Type: | Direct Vent |
| Type: | Condensing |
| Installation Type: | Indoor Only |
| Energy Star Rated: | Yes |
| Height (Inches): | 22.875" |
| Width (Inches): | 13-7/8" |
| Depth (Inches): | 10-13/16" |
| Gas Connection: | 1/2" |
| Water Connection: | 3/4" |
| Flow Rate at 40F Temp Rise (GPM): | 5.4 |
| Flow Rate at 50F Temp Rise (GPM): | 4.4 |
| Flow Rate at 70F Temp Rise (GPM): | 3.2 |
| Flow Rate at 60F Temp Rise (GPM): | 3.8 |
Questions?
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Call or text 888-757-4774
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Friday
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Saturday – Sunday
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Compare Similar Products
Brand
Energy Factor
Inlet Gas Pressure
Product Type
BTU (Max)
BTU (Min)
CURRENT ITEM
0.93
5.0-10.5"W.C.
Tankless Heater
120000
15000
You May Also Need
54 Replacement Parts
Filter Plug, 100074381
SKU: 100074381
TakagiKit, Inlet, Gas, 100076323
SKU: 100076323
AO SmithKit, Rod, Holder, 100074221
SKU: 100074221
AO SmithKit, Controller, Remote, Temp, Indoor, 100076567
SKU: 100076567
AO SmithOutlet Drain Plug, 100074383
SKU: 100074383
TakagiManifold Gasket, A, 100074229
SKU: 100074229
TakagiKit, Tube, Drain, 100076327
SKU: 100076327
AO SmithPressure Port, 100074227
SKU: 100074227
TakagiKit, Box, Junction, 100074668
SKU: 100074668
AO SmithKit, Heater, Inlet, 100074629
SKU: 100074629
AO SmithKit, Plate, Fixing, Heater, 16, 100074310
SKU: 100074310
AO SmithFlame Rod, 100074673
SKU: 100074673
TakagiKit, Clamp, Wire, 60, 100074233
SKU: 100074233
AO SmithKit, Ring, Gas Inlet, 100074234
SKU: 100074234
AO SmithManifold Gasket, B, 100074230
SKU: 100074230
TakagiKit, Wire, Remote Control, Indoor, 100076337
SKU: 100076337
AO SmithKit, Screw, M4 X 6, 100074512
SKU: 100074512
AO Smith
Need help finding a replacement part?
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Product Reviews
4.75 out of 112 reviews
95% would recommend this product
5 star
87%
4 star
8%
3 star
2%
2 star
1%
1 star
3%
Customer Images
Most Liked Positive Review
KEY WORD is MODULATING or VARIABLE CAPACITY
I am a licensed HVAC-R Contractor with a lot of experience in designing super efficient systems since 1980s. Installed this model for a customer in a single family home of 5 people in Maryland 3 Months ago to create more space in their utility room. Have not had any complaint even in the cold days with hot water issues nor did I expected to..
I knew the system would work and save my client a lot of money in utility cost because I have installed similar products before.
I have a Combi version of this type of tankless unit in my own house, it heats my radiators very efficiently and supplies unlimited hot water on demand and it lowered my gas bills consistently $150-200 a month compared to my neighbors on either side, without compromising any comfort.
The key for utility savings without compromising for comfort is the ability of these type of units to modulate Energy Consumption precisely as per demand...simply put, when water temp. is cold it will fire at 120K BTU as the water temp. rises the BTU required gets lower. For example if your target water temp is 130deg.F and the supply water temp. is 65deg.F, at start it will use 120K BTU as the water heats it will use 90K, 60K, 30K, all the way down to 15K BTU when water temp. reaches the target temp. hence using much less of your utility (gas or LP or Electric) thus saving you money and paying for itself.
Other important thing about these units are that, they are nice and quiet and takes no floor space.
I hope this can provide enough information for someone who is trying to make a very important decision.
VS
Most Liked Negative Review
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Unit was shipped with a stuck ballast in the gas feed
I got the unit in a timely fashion, however when the licensed plumber installed it, the unit would not fire up. I called Supply House and was told to call the in house Takagi representative . The plumber spoke with her. she was not very helpful. She had obviously never been out in the field and was just reading off some kind of trouble shooting guide. The plumber then reached out to another plumber here in Southern California who knew yet another Takagi representative- an outside technician who was much more experienced. After nearly an hour, the outside Takagi representative was able to walk the plumber directly to the problem. A simple manipulation of the stuck ballast freed up the gas fed and the unit was able to fire up. The unit has been working since then.
Showing 1-10 of 112 reviews
Great product
Great product easy install
Ted
Illinois
11 months ago
Verified Buyer
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Great unit but 3" venting is a bit of a pain to find
Love this little unit. I was a little worried with it being a lower btu model but we live in a warm climate and only have two bathrooms. It keeps up just fine for us.
The startup is very quick and just about instant once on standby.
Ryan
CA
11 months ago
Verified Buyer
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Excellent product
Installed this product in smaller home (2BR/1BA). 2 occupants. Plenty capable for all needs plus can easily handle guests. City water with softener. Included kit for ease in periodic flushing.
Butternut Biofuels LLC
Winona, MN
12 months ago
Verified Buyer
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I like the warrant on this product
It's a great value it's working fine so far
K
Chicago
1 years ago
Verified Buyer
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Yes & recommend to friends
Use in the rectory at church
Sue
Bakersfield
1 years ago
Verified Buyer
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Great product, great customer service
Unlimited hot water, and you are not spending money to keep it hot when you don't need it
Steve
MD
1 years ago
Verified Buyer
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Pleased
3rd tankless heater in 2600 sf 3 bathroom home. I had a Bosch for 12 years. It was hiccuping till the control board finally quit. Then I got another brand only to discover it did not reveal its restrictions and special needs. After installation it was discovered it wasn't appropriate for use with a circulation pump. So it was removed and returned. Then I bought this Takagi.
It is so much better than the Bosch...smaller, lighter, quieter. It is a very smooth operating machine. It is smaller, lighter, and comparable output. Best of all it works smoothly with my circulation pump. The efficiency myst be remarkable...the exhaust is barely warm and I don't know why there is little condensation from the machine or in the exhaust vent.
The downside is to have the warranty you must pay a licensed plumber to install it. I self-installed. I've been a repairman and installed a few water heaters in my day and lots of gas appliances in Restaurants. I specialized in restaurant work. So I sent my credentials hoping my pre retirement work was closely related enough.
Waiting for a response but it is outside their requirements.
Menace the Dennis
Sedona, AZ
1 years ago
Verified Buyer
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Takagi never disappoints
Supply House does not disappoint either,, Ordered and next day delivery well packed and everything goes as planned. I was able to serve another happy customer.
Just Call Bob
Central Ohio
1 years ago
Verified Buyer
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I have been installing the units for 17 years and only recom
I use takagi tankless water heaters in my home as well as my restored rentals. These units are easy to install and very reliable.
Tullahoma flipper
Tullahoma Tennessee
2 years ago
Verified Buyer
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I would buy this product again!
great compact product…I now have 2 takagi . ease of use, quiet, and very reliable!
Tommy
san jose, ca
2 years ago
Verified Buyer
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Product Q&A
3 Questions3 Questions
Q: T-H3M-DV-N can be vented with 2" pvc?
Asked by mikel6227 2 years ago
Add your answer
Verified Reply- SupplyHouseHello Mike, thanks for writing in. However, no this cannot be vented with 2" PVC. It will be vented with 3” PVC for venting up to 70 feet or 4” PVC venting up to 100 feet.
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Q: I have really hard water will this heater work or do I need to install a water softener
Asked by larry 9 years ago
Add your answer
Verified Reply- SupplyHouse StaffAccording to the manual, "Water hardness levels must not exceed 7 grains per gallon (120 ppm) for single family domestic applications or more than 4 grains per gallon (70 ppm) for all other types of applications. Water hardness leads to scale formation and may affect / damage the water heater. Hard water scaling must be avoided or controlled by proper water treatment."
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Q: I know these come highly rated and it seems a lot of customers install their own. I have read this brands demand that they be installed by a plumber to validate the warranty, otherwise too bad so sad if anything goes wrong. Question? What is the record on things going wrong with these units?
Asked by xraydave 9 years ago
Add your answer
Verified Reply- SupplyHouse StaffTakagi are high quality units which we have been selling for many years with very few problems. Most problems arise from improper installation or incorrect sizing. If you read the fine print on just about any big name manufacturers unit, tank or tankless, they stipulate that the unit must be installed professionally for warranty coverage.
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