What could cause excessive dust in a condo with hot water heat; or electric heat?

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.

If this has worked in the past check all the electrical connections and be sure they are tight. You might consider changing the breaker as excess trips tends to lower the trip point. Check the heating elements and be sure they are isolated from ground if not replace them.

1) Make sure factory-supplied insulation and cover are reinstalled over thermostats, or cooler room temperature causes thermostat to under-approximate tank temperature, and this causes overly hot water.
http://waterheatertimer.org/images/Tank-with-insulation-2-600.jpg
2) Replace both thermostats.
Sticking thermostat can seem to act normally when tested, but when left alone it sticks, causing runaway overheating.
http://waterheatertimer.org/How-to-replace-thermostat-on-electric-water-heater.html

More resources:
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Emergency steps:
Turn electric power off.
Release tank pressure by opening bathtub faucet on hot side.
Turn off water supply to heater.
You can turn water heater ON for short periods (1/2 hour) to make some hot water until repairs are made.

It sounds like runaway heating caused by shorted element, possibly caused by leaking water. But I cannot tell for certain what the problem is. Read following links and/or call plumber.
http://waterheatertimer.org/Leaking-water-heater.html
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html

Over-amping:
Look at watt rating label on side of tank.
For example 4500 watt water heater requires 30 amp breaker and 10 gauge wire.
If you have 20 amp breaker and 12 gauge wire, then change elements to max 3800 watts. Tank will heat more slowly.

You have to fix leaks, and I cannot see that problem. Call plumber or repost question with clear description of leak.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

I think this unit is A/C powered. Check for tripped circuit breaker. Make sure power cord is plugged in.

The most likely problem is that the thermostats are set too high. Remove the thermostat cover plates and look to see where the thermostats are set. The range should be between 120F and 135F. Liquids expand with heat so the higher the temp, the high the pressure. Decrease the setting on the thermostat until the leak stops.

The other likely cause is a head of air trapped in the top of the tank. After drawing hot water, it wiill be displaced by the incoming cold makeup water. This will compress any air in the top of the tank. As the water heats, the air will heat and pressure will build - possibly causing the leak. You can purge the tank of air by opening the pressure relief valve until water comes out (which I assume that you have already tried).

1 The hot water board is not of the correct rating thus getting heated up and burning. 2 There is a short circuit in the system which draws excessive current thus burning board. 3 I f the rating is correct than the material used is inferior.

The red reset button or ECO or energy cut off turns off power to electric water heater.
The ECO responds to temperatures in excess of 150 degrees F.

Preliminary work:
You can use thermometer to check water temperature immediately after ECO trips.
Compare water temperature against the thermostat setting.

There are 4 things that can cause ECO to trip:
1) Bad thermostat is sticking and letting element continue heating water, or ECO is reading incorrect temperature.
2) Factory installed insulation and cover missing from tank, and thermostat is exposed to cooler air and misreads tank temperature.
3) Element shorted to ground in center of element. This completes 120V circuit to ground which will cause element to continuously heat the water.
4) Loose wire near ECO causing high-heat electrical event.

Solution:
Check for missing insulation.
Check screw terminals for signs of high heat and burning >> tighten screws.
Replace both thermostats using detailed instructions given on link below.
http://waterheatertimer.org/How-to-replace-thermostat-on-electric-water-heater.html

If the problem continues after replacing thermostats, more troubleshooting is needed:
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html

For more self-help information about your electric water heater:
http://waterheatertimer.org/Do-it-yourself-water-heater-timer.html

For more help, add a comment and I will respond

Some dripping at pressure relief valve is normal, but are you saying it continues to run excessively hot? Does water in trailer feel extra hot?
The ECO, and/or Thermostat, should cut the power/flame before it gets too excessive.

If this is an electric unit, you have to remove the cover to locate the thermostat. It sounds like the thermostat is malfunctioning. The excessive hot water can cause a unit to leak due to the expansion of the unit due to the overly hot water. Make sure that your breaker is off before you remove the covers to expose the thermostat.