We know how much it’s frustrating for some users to set the Rheem tankless water heater temperature above the default setting. That’s the point we’re here for you with an effective guide on how to set Rheem tankless water heater to 140.
To adjust the temperature at 140 degrees F:
- Turn on the remote control.
- Turn off the gas and water shut-off valves to your water heater
- Press the UP adjustment button until the LED display blinks 120°F.
- Then press both UP and DOWN to stop the blink
- Finally set the temperature setting at 140°F.
Now from my own experiences of dealing with my Rheem tankless water heater, I’ll walk you through all the detailed procedures and nitty gritty in adjusting the water temperature effectively. Let’s dive in.
Table of Contents
How To Set Rheem Tankless Water Heater To 140 [2 Methods To Know]
When the term comes to set your Rheem tankless water heater temperature at 140 degrees F, there are up to 2 methods to apply. One, you can perform by remote and the other one can be done through the dip switches on the heater inside.
However, let’s jump right into the step-by-step procedures on each method to adjust the water temperature on your tankless water heater.
01. Adjust Rheem Tankless Water Heater Temperature To 140 Degrees F With Remote
In almost all Rheem tankless water heater models, there is a built-in remote controller from which you can set the water temperature from 120°F (49°C) to 155°F (68°C).
Though you’re serious about setting the temperature at 140°F, temperatures above 125°F (52°C) may result in severe burns from scalding. Thus according to the recommendation in the Rheem manual, changing this setting would be done completely at the user’s own risk.
Anyway, here are the simple steps to follow to set the remote control at 140°F:
Step #1: Start by turning on the remote controller of your tankless water heater.
Step #2: Now turn off the water and gas supply to your water heater by closing the water and gas shut-off valves.
Step #3: Press the Up adjustment button repeatedly until the display shows 120°F (49°C). Continue to hold the button until the 120°F on the display starts to blink.
Step #4: When the LED display starts blinking at 120°F, press and hold both of the Up and Down arrow buttons at the same time until the 120°F stops blinking.
Step #5: When done, press the Up arrow button until the display shows 140°F.
Step #6: Finally, turn on the gas and water supply to your water heater by opening the shut-off valves.
02. Adjust Rheem Tankless Water Heater Temperature To 140 Degrees F Without Remote
Apart from setting the temperature by the remote control, there is another effective method to adjust the temperature by dip switches on the control board. Here are all the needed processes to follow to adjust the dip switch settings:
Note: If you are technically inclined, dip switch adjustment should be done by a professionally trained person only.
Step #1: Start by pressing the power button to turn off your water heater. Also, unplug the unit heater from the power connection.
Step #2: Turn off the water and gas supply as well by closing the water and gas shut-off valves.
Step #3: Remove the attached four screws holding the cover panel in place. Remove the front panel and set it aside in a safe place.
Step #4: Locate the dip switches on the control board. From there, find out the DIP Switch #4 located at the top left-hand side of the PCB.
Step #5: Change the DIP Switch #4 setting to the “ON” position. By doing so, the LED on the remote controller will start flashing. You may even see the LED on the PCB flash.
Step #6: Press the “SW1” button on the left-hand side of the PCB. Continue to press it for more than 1 second. The LED on the PCB will illuminate continuously.
Step #7: That’s the point, change the switch setting back to the “OFF” position. Avoid altering any other DIP Switch. By just changing the switch, The LED on the PCB will stop illuminating and the display of the Main Remote Control will turn off.
Step #8: After completing all the above steps, attach the unit’s front cover and restore the power supply to your tankless unit. Turn on the remote controller.
Step #9: Turn on the gas and water shutoff valves and turn on the remote controller.
How Long Does It Take Time To Get Hot Water In A Rheem Tankless Water Heater At 140 Degrees F?
After adjusting the temperature, your first concern would be how long your tankless unit will take to heat the water at your desired temperature. Well if it is 140 Degrees F, you won’t need to wait for more than 5 seconds for hot water. Within 5 seconds you will start getting the hot water at your hot water fixtures.
For more confirmation, here I’m going to provide you a temperature setting and time relationship chart, recommended by the Rheem manufacturer. I always use this chart while setting the temperature of my Rheem tankless model. Feel free to take a look!!
| Water temperature | Time to produce a serious burn |
| 120°F (49°C) | More than 5 minutes |
| 125°F (52°C) | 1 1/2 to 2 minutes |
| 130°F (54°C | About 30 seconds |
| 135°F (57°C) | About 10 seconds |
| 140°F (60°C) | Less than 5 seconds |
| 145°F (63°C) | Less than 3 seconds |
| 150°F (66°C) | About 1 1/2 seconds |
| 155°F (68°C) | About 1 second |
Is 140 Degrees F Right Or Too Hot For A Tankless Water Heater?
Though you are favorable to hotter water, 140 Degrees F will be enough higher if you want to go for the shower at this temperature. It may result in not only wasting your money but also increasing the risk of serious burns from scalding. So, 140 Degrees F will certainly not be recommended if you have small children or elderly people in your household.
If you are looking for the perfect temperature for your hot tankless water heater, 120 degrees Fahrenheit or 49 degrees Celsius is recommended for you. This temperature level is efficient enough to avoid scalding and saving energy bills for the most part.
But lower than that can increase the risk of growing Legionella bacteria, which causes Legionnaires’ Disease. In short, 140°F can cause severe burns to the human body in five seconds, and lowering temperature more leave the risk of contaminating your water supply with bacteria.
Though 140 Degrees is too high for a home tankless water heater, you can adjust this setting for commercial use. Even this temperature level is good for deep cleaning. Thus many dishwashers require to set the temperature between 130 F and 140 F in order to operate optimally.
Energy Costs Of Increasing The Water Temperature To 140 Degrees F
Do you know, setting your water heater temperature at the right level is effective enough to save your overall energy bills? Yes, you got it right! Generally, a water heater is responsible for about 14-18% of a home’s energy consumption. But, every time you’re lowering the temperature by 10 degrees Fahrenheit, you will end up saving up to 3-5% on energy costs.
According to the Department of Energy, turning up your water temperature to 140ºF, your water heater accounts for a waste of anywhere from $36 to $61 annually in standby heat losses and up to $400 in demand losses. Thus try to limit your water heater temperature to 120ºF, which is considered safe for the majority of reasons.
How To Limit Maximum Temperature Setting To 120°F In Rheem Tankless Water Heater?
If you want to adjust the maximum water temperature setting to 120°F (49°C), here are the simple steps to follow out:
Step #1: Turn on the remote control. At the same time, turn off the gas and water supply to your water heater through the shut-off valves.
Step #2: Press and hold the DOWN adjustment button repeatedly until 100°F (38°C) or 85°F (29°C) shows in the LED display.
Step #3: When done, press the UP and DOWN adjustment buttons at the same time and the number will stop blinking.
Step #4: Now press the Up adjustment button and set your desired temperature.
FAQs:
What is considered safe water
temperature for a bath?
According to dermatologists and experts, it is best to set the bath water temperature just slightly above the body temperature. That would be recommended between 90° F and 105° F (32° C – 40° C).
How to change the temperature settings down to 85°F?
To turn down the temperature at 85°F (29°C):
1. Turn on the remote control and turn off both gas and water supply.
2. Press the DOWN adjustment button repeatedly until 100°F.
3. Now press the Down button 3 times within 5 seconds & set temp at 85°F.
Does outside temperature affect the water heater?
Yes! When it’s cold outside, it can affect your water heater performance. You’ll have to wait longer for the water to heat up. For instance, you need to insulate the plumbing system of your water ether to heat up the water effectively.
In Closing
Now that you know how to set Rheem tankless water heater to 140, it will be quite easier for you to run the unit at this temperature range. No matter, whether you have a built-in remote controller for your water heater or not, you’ve described both of the procedures with a remote and without one.
In case, if you’ve tried all the steps described above, still you can’t get the right temperature, there may be other issues. For instance, our comprehensive guide on no hot water in Rheem tankless water heater has all the answers you need to get hot water again.
Also, always be concerned about Rheem tankless water heater maintenance to guarantee your water heater performs at its best for you and your family.