Bradford White Electric Water Heater

hot_rod

Did you check the temperature that the reset pops also?

There is a small metal disc that distorts and moves position as it gets warmer. I'm not sure how you would check the high limit function without taking the tank to 200F plus.

For the cost of those snap-disc controls a replacement may be cheaper than return calls?

You're sure they are wired correctly? Top element on first, when it meets the temperature it switches to the bottom stat.

Either one could be over temp-ing, or the limit one is too low.

hot rod

Rodney Summers

Bradford White Electric Water Heater Triping

I have a 40 BH electric water heater that will trip the high temp safty onece in a while.

I have checked temps cut in cut out and have found all to be working correctly? This tank was installed 2002.

Glenn Sossin_2

expansion tank ??

The T&P valve has 2 functions, temperature and pressure. It is likely that your problem is pressure not temperature.If this is an intermittent situation, the following scenario would apply.

Do you have an expansion tank on the cold water side? If you don't, thats the likely cause of your problem.

To the best of my knowledge, most residential water services have checks in the meters, or backflow devices intalled. The function of these devices is to allow water to travel only 1 direction - into your home, not out.

If there happens to be a spike in water pressure, and no valve opens in the house to release it, the pressure could be several pounds higher than normal. If this spike happens to occur at the same time you just emptied your water heater, the pressure in your system will rise as the water is heated. If there is no expansion tank, the added heat energy will result in an increase in pressure - sufficient to pop your saftey valve.

It's the same reason you have an expansion tank on your boiler system. As the water is heated, it wants to expand. I've included a graphic representation of the relationship between pressure and temperature based on a fixed volume system - such as a non expandable water heater tank. You will see even a change from 70F to 90F will result in almost 190lbs increase in pressure.

Rodney Summers

Interesting; sometimes you have to think outside the box and apply common knowledge in one system to another.

Add another thought to the problem and I think we may have the cause. When I installed this tank a Grounfause circulator with the built in timer was installed.

Plug this into the problem with the right incoming water temps, timer, usage, and prehaps voltage fluctuation a trip most likely would occur.

The expansion tank would give a place for the extra energy to go and no one would be the wiser to the amazing feats that are occurring within a system so often taken for granted.

Larry Weingarten

Just to confirm...

... it's the red high limit button above the upper element that's popping? If so, check both elements for any current leak to ground. Use the ohms times 1000 scale. Check between each screw and the flange of the element. Any leakage means the element is slowly heating all the time. Do make sure the power is off or you'll fry the meter. I've fried quite a few ;~)

Yours, Larry

mtfallsmikey

High temp limit

Standard trip temp is 170 deg. Never had this problem with BW heaters, but maybe they are using the Appco (sp?)thermostats now, which are notorious for poor calibration and overshoot. Those are found on GE, Whirlpool, and all other heaters mfd. by State for other OEM's. Check operation of bottom t-stat/element first. Why are most electric HWH's made in Tennesee anyway?

Glenn Sossin_2

Didn't Read it right

Have to clean my glasses

Dustin Bowerman

Bradford White electric water heater

Good morning Rodney,

You are describing a thermostat that may not be regulating temperature accurately. Many of the water heaters will have an upper and lower thermostat, and either one can be causing your temperature high limit to trip. I would suggest replacing both the upper and lower thermostats. Make sure the replacement thermostats are wired correctly and that they are secure against the water tank itself.

Good luck!

Dustin Bowerman

Bradford White Corporation