Frequent tripping of the hight limit switch

If you have already descaled your Tempra 24 Tankless water heater and replaced the flow sensor, but the high limit switch is still tripping, there could be a few other possible causes of the issue: Malfunctioning thermostat: A malfunctioning thermostat may cause the heating modules to overheat, which can trip the high limit switch. You may need to replace the thermostat if this is the case. Insufficient water flow: The Tempra 24 Tankless water heater requires a minimum flow rate of 0.5 gallons per minute to operate properly. If the flow rate is too low, the heating modules may overheat and trip the high limit switch. Check the water flow rate to ensure it meets the minimum requirement. Electrical issues: If the wiring or electrical connections are faulty, it may cause the heating modules to overheat and trip the high limit switch. You may need to inspect the wiring and connections to ensure they are intact and properly connected. If none of the above solutions work, it may be best to contact a professional technician for further diagnosis and repair. It is unlikely that you would need to replace the entire unit if the issue is isolated to a single heating module.

Why Does My Electric Water Heater Reset Button Keep Tripping? So the red reset button on your electric water heater keeps popping out and needing to be reset.
Here's the most likely problem: The water in your water heater is getting too hot.
When the water temperature in your water heater exceeds 180°, the red reset button (also known as the high-limit switch) trips. This tripping protects you from getting scalded or burned when using hot water in your home.
OK, but then what's causing the water in your water heater to get so hot? The most likely cause is a bad thermostat.
How a bad thermostat causes your water heater reset button to trip Electric water heaters have a lower and upper thermostat-one for each heating element.
The thermostats are responsible for controlling the heating elements. When the water has cooled off, the thermostats kick on the heating elements to heat the water. And once the water has reached your desired temperature, the thermostats shut off the heating element.
(This is very similar to the way your heating and air conditioning thermostat controls your home HVAC system.)
But these thermostats can go bad. When they do, they sometimes get stuck in the "on" position. This means that that the heating element continues to heat your water, eventually causing the high-limit switch to trip.
The fix: The bad thermostat needs to be replaced. A plumber can use a multimeter to test the thermostats and find out which one is bad.
Other problems that can cause your high-limit switch to trip While a bad thermostat is the most common reason your water heater's reset button may trip, it's not the only one. Other common causes include:

• A shorted heating element-It may be that the thermostat is working just fine and shutting off the heating element. But a short in the element is causing it to continue to heat your water.
• Loose wiring-A loose wire in the water heater can generate heat that can cause the high-limit switch to trip.
• Bad high-limit switch-The switch itself may be malfunctioning and tripping when it shouldn't be.

Get a professional plumber's help

Do you live in the Minneapolis-St. Paul area and need a reliable plumber to help you troubleshoot your water heater problem? Contact MSP Plumbing. We can usually fix the problem the same day.

Check the resistance or thermostat.

There are several possible causes, but the first to check is the limit switches. When the gate opens, it is supposed to trip a limit switch that tells the mechanism that the gate is fully open. If the switch is not tripped, it will not respond properly to a command to close. It may think the gate is running into an obstruction and then just shuts down.

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H1 indicates the high limit switch has been tripped. Usually, only a temperature of 114 degrees will trip it or the switch itself may be bad. Depending on your setup, if you just have a normal mechanical time clock, you should have a fireman's switch wired in that will shut the heater off 15 minutes before the pump shuts off.
This can also be caused by a bad or improperly adjusted pressure switch. This can be tricky especially if the heater is installed below the pool water level. If you know that the heater has not tried to fire when the pump is off, then I would suspect the high limit switch has failed and needs replaced.

Check the high limit thermostat. if its damaged, it will allow the dryer to become way to hot, tripping the shut off. check the door switch as well. if its faulty, it will shut off the dryer periodically.

The limit switch on the inducer has tripped. There are two wires that go to a small disk about the size of dime that has a small button in the center. Push this little button and you will feel a littl snap and the unit should fire up. Check all the manual reset limits as well. If the unit still won't start, jump the two wires by bypassing the limit switch. If it starts, then replace the switch. Bypassing the switch is only temporary and could lead to death if it is used as a permenant fix.

The blower motor kicks on when there has been a 24 volt control failure.

This usually means that a limit switch has tripped.

Most likely that would be a high temp limit switch or a rollout switch.

First, make sure the filters are clean. and the evap coil is clean. If eaither are dirty/clogged, it will partially block airflow, causing the furnace to overheat, causing the high temp limit to trip.

A rollout switch typically trips for three reasons.
1 flame rollout into the burner compartment due to poor airflow.
2 overheating af teh metal plate the rollout is mounted to, due to dirty, old, rusted components.
3 a bad limit switch.

If your unit has an LED light, count the flashes and it will hepl popint out the problem.
(locate the wiring diagram/flash code list, and correspond the flash count, with the code.)

First, check filters.

This is the cause of a faulty thermostat. You may also want to consider replacing the high limit as well if it has tripped more than a few times.