Free Shipping on Orders Over $200*

Takagi Tankless Water Heater used as Heat Source

We recommend that you use the Direct Vent Kit for your Takagi Water Heater as this can save you (On average) 15% on your heating bills vs a non-direct vented Water Heater.

There are primary and secondary loops and the primary is the loop attached to the Takagi. The secondary loops are the high and the low temperature heating loops.

To get one high temperature from the Takagi you need to use a primary loop and then a secondary loop to feed your system.

To get one low temperature from the Takagi you use a primary and secondary and wire as below.

There are various methods for wiring but the best method is to shut off the primary circulator based on the return of the low temperature water so as to not short cycle the Takagi.

To get your heat and your domestic hot water from the Takagi you can use many methods. The best method is to use an indirect water heating tank driven off the high temperature loop. How to set up a Takagi T-KJr2-IN for use as a Hydronic Radiant Heat Source

List of materials needed for a project like this (Click Link below to Purchase Product and see more Information)

Hydronic Heating Side (Trim)

Quantity 1 - Takagi Gas Tankless Water Heaters

Quantity 1 - Hydronic Heating Mixing Valves

Quantity 2 to 4 - Ball Valves for Hydronic Heating Side

Quantity 1 to 2 - Boiler Drain and Hose Bibs

Quantity 0 to 2 - Temperature Guages and Tees

Quantity 1 - Hydronic Heating Expansion Tanks

Quantity 1 - Cast Iron Pump (For Primary Loop - Larger Pump Depends on System)

Quantity 1 - Pump Flanges (For Primary Loop Side and Most Likely 1 Inch to 1 1/4 Inches)

Quantity 2 + - Cast Iron Pump (For Secondary Loop - Amount of Pump Depends on System)

Quantity 2 + - Pump Flanges (For Primary Loop Side and Most Likely 3/4 Inch)

Qunatity 1 - Hydronic Circulator Switching Relay

Quantity 1 - Hydronic Heating Thermostats and Floor Sensors

Quantity 1 - Hydronic BackFlow Preventers and Combo AutoFill Valves

Quantity 1 - Hydronic Air Eliminators, Air Separators, Air Scoops and Dirt Separators

Quantity 1 - Hydronic Boiler Pressure Relief Valves and Water Heater Relief Valves

Quantity 1 - Taco Flo Checks Valves


Hydronic Heating Side (Distribution)

Quantity X - Hydronic Radiant Heat Pex Tubing (Depends on Systyem)

Quantity X - Hydronic Radiators and Convectors (Depends on System)


X = Various Amounts of Product needed - dependant on actual system