Why does water heats with indicator light off

On Rancilio coffee machines, the meaning of the green and orange lights can vary depending on the specific model and configuration of the machine. However, in many Rancilio espresso machines, the lights are used to indicate certain states of the machine during operation. Here are some common interpretations for the green and orange lights:

1. Green Light: The green light on a Rancilio coffee machine typically indicates that the machine is powered on and ready for operation. When you turn on the machine, the green light should illuminate to show that it has power.
2. Orange Light: The orange light often indicates that the machine is in the process of heating water to the optimal brewing temperature. Once the water reaches the correct temperature, the orange light may turn off, and the machine is ready for brewing.
3. Blinking Orange Light: A blinking or flashing orange light might signify that the machine is in a heating phase, and the water is being heated to reach the appropriate temperature. This is common during the initial warm-up or after the machine has been idle for a while.
4. Red Light: Some Rancilio machines might use a red light to indicate specific alerts or warnings, such as low water level, need for maintenance, or other issues

Usually spas heat approx 5 degrees an hour. If its been a day or so and your water isn't up to heat, you probably need a new heating element in your spa. Check the voltage at your heating element, and on your topside there is usually a heat indicator light that should be lit. If it has correct voltage at heater and the indicator light is lit, heater burned up. If you have incorrect voltage at heater check fuses for a possible blown fuse and see which pump it goes to, that could be your problem.

check the pressure switch by bypassing it and see if the heat indicator stays lit.If it is not heating it could be a couple of things. First thing to check is the filter. remove it from the hot tub and see if that solves the problem.if it does not then perhaps the pressure switch is bad.always a chance you have a bad temp sensor if it is running but not heating if the heat indicator light is lighting up.

Rod
US Parts Center
888-521-6183

Run some WHITE vinegar through it, followed by plain water a few times. The heating system gets a buildup in it and requires cleaning from time to time.

AO Smith uses the Honeywell ICON gas valve with green indicator light.
Some models use White Rodgers Intellivent with a row of indicator lights.

The gas control blinks the error code:
Open following links to identify gas control thermostat and read possible error codes:
http://waterheatertimer.org/pdf/Honeywell-Gas-Valve-LED-Codes-2000.pdf
http://waterheatertimer.org/BW.html#Temp
http://waterheatertimer.org/How-to-adjust-water-heater-temperature.html#intelli

I just got the exact IcedTea maker that you have (model TM4) from Mr. Coffee. I think that we were both trying to make it work the same way, which is wrong. The plastic pitcher goes on the bottom, while the part that plugs in with the button&indicator light goes on the top. Put water in the pitcher to the indicated water line and then pour it into the part with the metal basket. I didn't have any directional sheet either so I didn't know that the water goes in there. I thought the water would be gently warmed while in the plastic pitcher. After pouring water into the heating part, fill the pitcher with ice to indicated level (about 2 ice cube trays). Place the heating part with the button&indicator light on top of the plastic pitcher and cover it with the white lid. Push the button and it will heat the water and dispense the brewed tea into the pitcher thru a valve. The indicator light will go off when the brewing process is done. The entire manual can be downloaded from going to: http://www.mrcoffee.com/manuals/MrCoffee/tm4.pdf I hope this helps you if you still have the item. I bought mine to give my daughter while in college. I really like that it is so space saving compared to many that I am finding in stores today. Good luck and happy brewing!!! Susan

the flashing heating light indicates that it isn't getting water. This could indicate that your pump has gone bad.

try descaling it sound light its full of scale

I installed a tankless heater in my home, I had the same problem, I discovered that the unit was not adequate for the water flow that I needed, I went up to a bigger unit and solved my problems, check to see what the flow rate is recommened for yours

Bathtub heaters will not produce the heat out a the jets like you would feel coming out of a return jet in a swimming pool.
Bathtub heaters will ONLY maintain whatever temperature water you put in there. they only heat 1-2 degrees an hour. that is for a 1500 watt heater. Many heaters today are only 650 watt or perhaps 700 watt.