Water Heaters - hot water high limit switch
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B.C. WINSTEAD
12-14-06, 07:47 PM
Help.........
could some one enlighten me on the reason that I have to keep reseting my high limit switch on my electric hot water heater ?
could some one enlighten me on the reason that I have to keep reseting my high limit switch on my electric hot water heater ?
HVAC-EMT
12-14-06, 08:56 PM
Help.........
could some one enlighten me on the reason that I have to keep reseting my high limit switch on my electric hot water heater ? There are a couple possibilities. The thermostat/aquastat could have failed, causing the element to be powered beyond the setting. The thermostat could be set too high. The thermostat might not be making good contact with the water heater. In either case, check your hot water temp at the tap, try to figure out if either element is running, the upper or lower, and turn it down till it de-energizes the element. Check that the thermostats are secured to the w.h.. Another possibility is that the high limit switch could have failed. If the water temp never reaches scalding temps, then this is probbable. Also, the element could have failed. They are switched only on one side. If it switched end of the element is grounded, it will heat with 120V instead of 230V even if the thermostat isn't calling. Troubleshooting will be a lot easier if you have and know how to use a multimeter with an amp clamp. I hope this helps!
could some one enlighten me on the reason that I have to keep reseting my high limit switch on my electric hot water heater ? There are a couple possibilities. The thermostat/aquastat could have failed, causing the element to be powered beyond the setting. The thermostat could be set too high. The thermostat might not be making good contact with the water heater. In either case, check your hot water temp at the tap, try to figure out if either element is running, the upper or lower, and turn it down till it de-energizes the element. Check that the thermostats are secured to the w.h.. Another possibility is that the high limit switch could have failed. If the water temp never reaches scalding temps, then this is probbable. Also, the element could have failed. They are switched only on one side. If it switched end of the element is grounded, it will heat with 120V instead of 230V even if the thermostat isn't calling. Troubleshooting will be a lot easier if you have and know how to use a multimeter with an amp clamp. I hope this helps!
Ed Imeduc
12-14-06, 08:57 PM
If the water gets to hot You can have a bad tstat at the top or bottom. The tstat on a water heater arent the best in the world
Kenmack70
10-15-07, 08:37 AM
Can you check the elements (power removed) with a multimeter without emptying the tank?
Thanks again.:confused:
Ken Mack
There are a couple possibilities. The thermostat/aquastat could have failed, causing the element to be powered beyond the setting. The thermostat could be set too high. The thermostat might not be making good contact with the water heater. In either case, check your hot water temp at the tap, try to figure out if either element is running, the upper or lower, and turn it down till it de-energizes the element. Check that the thermostats are secured to the w.h.. Another possibility is that the high limit switch could have failed. If the water temp never reaches scalding temps, then this is probbable. Also, the element could have failed. They are switched only on one side. If it switched end of the element is grounded, it will heat with 120V instead of 230V even if the thermostat isn't calling. Troubleshooting will be a lot easier if you have and know how to use a multimeter with an amp clamp. I hope this helps!
Thanks again.:confused:
Ken Mack
There are a couple possibilities. The thermostat/aquastat could have failed, causing the element to be powered beyond the setting. The thermostat could be set too high. The thermostat might not be making good contact with the water heater. In either case, check your hot water temp at the tap, try to figure out if either element is running, the upper or lower, and turn it down till it de-energizes the element. Check that the thermostats are secured to the w.h.. Another possibility is that the high limit switch could have failed. If the water temp never reaches scalding temps, then this is probbable. Also, the element could have failed. They are switched only on one side. If it switched end of the element is grounded, it will heat with 120V instead of 230V even if the thermostat isn't calling. Troubleshooting will be a lot easier if you have and know how to use a multimeter with an amp clamp. I hope this helps!
Kenmack70
10-15-07, 08:50 AM
What is the purpose of the High-Temp Limit Switch?:thinker:
Thanks again.
Ken Mack
Thanks again.
Ken Mack
sheph
03-12-08, 01:24 PM
What is the purpose of the High-Temp Limit Switch?:thinker:
Thanks again.
Ken Mack
Well if the water heater gets hotter than the thermostat should allow it will usually cause it to overflow out of the pressure relief valve. However if it gets stuck it could cause the tank to explode. Feel free to bypass it at your own risk... :D (not really I'm kidding). Not only that it wastes energy when it is trying to keep the water hotter than it should be. The most likely cause of this problem is a bad thermostat on the upper or lower side of the tank.
For the person who asked about multimeter testing do the following to check and see if the thermostat is bad:
Reset the ECO switch and let the water get good and hot (about 20-30 minutes)
Turn off the circuit breaker to the water heater.
Check ECO and make sure it hasn't poped again.
Turn the thermostat control all the way up
Test the points between the incoming and outgoing electrical connections to the thermostat. You should get a '0' reading (as long as the water isn't so hot that it's beyond the scope of the thermostat).
Now turn the thermostat all the way down and test again, you should have resistance now, how much depends on your ohm setting but it should be fairly close to complete resistance or '1' which is an open connection (unless the water is so cold that it is beyond the lower end scope of the thermostat).
Do that for both the top and the bottom and it should help you to isolate which one of the two thermostats are bad.
Thanks again.
Ken Mack
Well if the water heater gets hotter than the thermostat should allow it will usually cause it to overflow out of the pressure relief valve. However if it gets stuck it could cause the tank to explode. Feel free to bypass it at your own risk... :D (not really I'm kidding). Not only that it wastes energy when it is trying to keep the water hotter than it should be. The most likely cause of this problem is a bad thermostat on the upper or lower side of the tank.
For the person who asked about multimeter testing do the following to check and see if the thermostat is bad:
Reset the ECO switch and let the water get good and hot (about 20-30 minutes)
Turn off the circuit breaker to the water heater.
Check ECO and make sure it hasn't poped again.
Turn the thermostat control all the way up
Test the points between the incoming and outgoing electrical connections to the thermostat. You should get a '0' reading (as long as the water isn't so hot that it's beyond the scope of the thermostat).
Now turn the thermostat all the way down and test again, you should have resistance now, how much depends on your ohm setting but it should be fairly close to complete resistance or '1' which is an open connection (unless the water is so cold that it is beyond the lower end scope of the thermostat).
Do that for both the top and the bottom and it should help you to isolate which one of the two thermostats are bad.