Takagi Tankless Water Heater Standby: Does It Save Energy?

Have you ever noticed an illuminated orange LED light on your Takagi water heater? Are you confused about what it is and why it appears? It’s the Takagi tankless water Heater standby mode.

The standby mode indicates the heater is on but it’s now idle. In the standby mode, the heater doesn’t actively work and the purpose of this mode is to save energy. 

Now it seems interesting right? It should be because this feature is a greater money saver. Read this article and figure out everything about the Takagi water heater standby mode. 

takagi tankless water heater standby

What Is The Takagi Tankless Water Heater Standby?

Standby mode on Takagi water heaters means the heater is on but not heating to save energy. However, the heater is always ready to start quickly when you need hot water. The heater also checks itself for problems and takes a break after maintenance to make sure everything is okay before working again.

01. Purpose Of Standby Mode

If you’re wondering why exactly this feature is required then check the below segment, 

  • Energy Conservation: The first purpose of standby mode is to save energy. By switching to standby mode when there is no demand for hot water, the unit avoids continuously heating water. Eventually, it’s saving energy.
  • Quick Response to Demand: Standby mode allows the unit to be ready to heat water instantly when you need to heat the water again. This makes sure you get hot water instantly all the time when you need it, without the need for preheating.

How Do You Know Your Takagi Water Heater Is On The Standby Mode?

Are you confused about whether your Takagi water heater is on standby mode or in regular mode? Well, just look for the orange standby LED on the heater. When it’s on, it means the tankless water heater has power and is waiting in standby mode for your next command.

Remote Controller Functionality Of Takagi Tankless Water Heater Standby 

In this segment, I’ll show you how you can activate, deactivate, and switch from the standby mode of your Takagi tankless water heater. 

standby mode of takagi tankless water heater

01. Standby Mode Activation

If you want to activate the standby mode then let’s check out the procedure below. 

  • If you have a remote controller, the first thing to do is make sure its power button is on. This lets the remote talk to the tankless water heater.
  • After turning on the remote’s power button, press it again until you see the amber Stand-By LED light up. This light tells you that the remote is ready to control the tankless water heater.

02. Turning Off/Switch From Standby Mode

Now it’s time to know how you can switch from standby mode or deactivate it. 

  • To switch from standby mode to making hot water, press the on/off button on the remote or temperature controller.
  • Pressing the on/off button will turn off the amber standby light. This means the tankless water heater is not in standby mode anymore and is ready to provide you with hot water.

Electrical Specifications Of Standby Compare To Other Modes

Mode/Model240 (Indoor/Outdoor)340 (Indoor/Outdoor)540 (Indoor/Outdoor)
Operation  72.7 / 0.61 78.2 / 0.6589.0 / 0.74
Freeze Protection174 / 1.5174 / 1.5175 / 1.5
Standby3.1 / 0.033.1 / 0.034.2 / 0.04

NB: Here the electric consumption units are shown by W/A (Watt/Ampere)

  • Watt represents the power consumption 
  • Ampere represents the current consumption

The above table indicates the power usage of the Takagi water heater when it is in different modes. Now let’s compare the operation, freeze protection, and standby mode. 

01. Operation Mode

The Takagi water heater is in a high-power state in the operation mode. It consumes 72.7 watts of power and draws a current of 0.61 amperes when it’s in operation mode for the 240 Indoor/ Outdoor model. For 340 and 540 (Indoor/Outdoor) models, the electric consumption rate is consecutively 78.2 / 0.65 and 89.0 / 0.74.

02. Freeze Protection

In the freeze protection mode, the heater is in the highest power state. For 540 Indoor/ outdoor models, it consumes 175 watts of power and draws a current of 1.5 amperes. And for the 240 and 340 (Indoor/Outdoor) models, the heater consumes a power of 72.7 watts and draws a current of 0.61 amperes.

03. Standby

Now you’ll see the difference in the standby mode as the heater switches to a low-power state. When the heater is in standby mode, it consumes only 3.1 watts of power and draws 0.03 amperes of current for the 240 and 340 (Indoor/Outdoor) models. For 540 Indoor/ outdoor models, it consumes a power of 4.2 watts and draws a current of 0.04 amperes. 

So, we can see the power consumption rate in the standby mode is relatively low. It helps to save energy and ensures that the heater is always ready to work without using a lot of electricity when it’s not heating water.

4 Cases When Takagi Water Heater Standby Will Be Activated Automatically?

Sometimes you might get confused seeing your water heater unusually switching into the standby mode. Don’t worry, it’s common for a few certain cases. Check out them below.

01. Flow Rate Is Too Low During Activation

If there’s not enough water flowing through the heater the heater will remain in the standby mode until it gets a sufficient flow rate. For most of the Takagi water, the required flow rate is greater than 0.5 gallons per minute (GPM).

02. Temperature Rise Not Enough During Activation:

The heater requires a certain temperature rise to begin operation. If the heater doesn’t reach at least a certain temperature of 15,000 BTUH for natural gas (13,000 BTUH for propane) the heater will stay in standby mode.

03. When The Flow Rate Drops

When you shut down the heater, the flow rate drops below 0.4 GPM (Deactivation point). When the flow rate drops the heater automatically to the standby mode. 

04. Using The Remote Control

If you’re using a remote control and turn it on, then press the power button until an amber light the heater goes into standby mode (usually 5 seconds).

Takagi Tankless Water Heater Standby Not Working

Based on my personal experience, I’ve never faced issues like the Takagi water heater standby not working. However, it may happen in rare cases and most of the time it’s not an issue of the Takagi water heater.

Maybe your standby mode is working but the oranger LED is not illuminating. In that case, you should call for an electrician or contact the Takagi Technical Service Department to fix the orange LED.


Does a tankless water heater stay on all the time?

No, tankless water heaters do not stay on all the time. They operate on demand, heating water only when it is needed. When the purpose of heating is done they switch to idle/standby mode.

Does a tankless water heater need to be shut off?

Yes, it’s necessary to turn off your tankless water heater when you go on a long vacation. If you leave it on, there’s a risk of leaking the water heater.

Do tankless water heaters save money?

Yes, tankless water heaters can save money on energy bills. If your home uses 41 gallons or less of hot water every day, your heaters are around 24% – 34% more energy efficient compared to regular water heaters with storage tanks.


I hope now you have a better understanding of the Takagi tankless water heater standby mode. Whether you know it or not this is a money-saver the user should highly appreciate it. So, no more getting frightened when you see an orange LED on your water heater.

I don’t want to prolong the content. Let’s wrap it up and if you’re interested then you can read my other article on the Takagi tankless water heater reset button.

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