Water heater question(s)

[drw]

We recently went with a Tankess water heater (gas). My old heater was in the attic, directly over the master bedroom. Over the years, I worried about the potential damage if the heater had major leak. This fall my neighbors came home from work to find that their tank (also in the attic) had sprung a major leak, which resulted in two weeks in a motel and $40,000 in repairs. Since my heater was two years older than theirs (mine was 12 years old), I figured I was living on borrowed time. I had hoped to relocated a new conventional heater to less vulnerable spot, but I really did not have any viable options...consequently, we went with the a tankless model located on the outside of the house. Yes, it was expensive ($3,200), but I feel good about the decision, and I have been very pleased with the performance of the tankless technology.

Donn

 

[Glennbear]

Not trying to take this thread too far afield but my curiosity has been piqued. :icon_scra I seem to recall from my days as a building inspector back in ancient times that whenever a HWH was over an occupied space a catch pan with drain was mandated. That may have been a regulation perculiar to NJ (there are many :gar-La. Even if it is not mandated, if mine was in the attic (it is not) I would want a catch pan. :wsmile:

 

[Tarhead]

Bill (aplpikr),
Please explain why you need to maintain the temperature of a tank of water all night and most of the day if you only need it to be up to normal temperature for a few hours in the evening or morning. We have a stand-by button on our water heater and press it when we leave for the day or go out of town and turn it back on when we return. It's a habit we got into living in Germany where we heated water one small tank at a time...and for a short time with coal! If we forget to turn it back on, even after being off for the whole day, we can still take a shower in the evening with a water saving shower head and not run out of hot water.

The rationale for that hot water still being in the tank as a cost doesn't make sense to me as that is a function of the insulation and the amount of water in the tank that was heated the night prior when we need full temp water and we don't have control over that. We've already paid to heat up our 40 gal. tank and are still using it. We just didn't have to keep paying for energy to keep it at full temperature when there was no possibility of a big demand.

 

[junquecol]

Not trying to take this thread too far afield but my curiosity has been piqued. :icon_scra I seem to recall from my days as a building inspector back in ancient times that whenever a HWH was over an occupied space a catch pan with drain was mandated. That may have been a regulation perculiar to NJ (there are many :gar-La. Even if it is not mandated, if mine was in the attic (it is not) I would want a catch pan. :wsmile:

Pans are required, but remember that the drain from the pan is gravity, while the leak is pressure. The drain would have to be at least 2" pipe to handle a "sure enough leak." Drains under WH are designed to catch those small leaks. If the pop off lifted, most couldn't handle it.

 

[Glennbear]

Pans are required, but remember that the drain from the pan is gravity, while the leak is pressure. The drain would have to be at least 2" pipe to handle a "sure enough leak." Drains under WH are designed to catch those small leaks. If the pop off lifted, most couldn't handle it.

Thanks Bruce, as I recall piping the safety to the exterior was permissible as long as the line was not valved along it's length and the final pipe was not threaded at the end. :wsmile:

 

[aplpickr]

Tarhead:
You answer your own question. If the water is still hot when the heater is turned off, then it still would have been hot without the thermostat cycling on, if the power is on. The meter does not spin until the thermostst clicks. What I am trying to say is, "This is a fictious money saver. If there is no load, because of modern insulation, then there is no money wasted." If heater was made before 1988, then the insulation is not as good. Is the supposed $4 monthly savings worth a case of food poisoning because the dishes were not sterilized?

 

[Glennbear]

This seems to be a good time to mention the following from a plumbing information site, although the risk is slight it bears mentioning:

In your home there is a rocket. It weighs between 300 – 1200 Lbs. and can, without even a moment’s notice launch itself through the roof of your home, fly several hundred feet in the air, and land a block away. This rocket hides in basements, closets, garages, attics, and even under kitchen counters. However, there is a simple test you should do at least once a year that can assure the rocket will never launch. The rocket is your water heater and you need to test the T&P Valve at least once a year to make sure it is working properly.
There are many times when the potable water system in a home can become a “Closed System” meaning water can only flow into the home and not out. This is a desirable thing as it can guard against contaminants entering the water supply in a backflow situation. Whether it is a check valve in the meter or, elsewhere, or, a pressure reducing valve without a bypass your system can become a closed system. When a system is closed dangerous pressures can build in the system when the water heater reheats due to thermal expansion or, a malfunctioning water heater that heats the water too hot. The maximum working pressure in a water heater is 150 PSI this is established by testing and design. In all reality the actual burst pressure is much higher as the working pressure is a derated safe figure and the burst pressure is probably in the 300 PSI range.
The T&P valve has 2 functions. “T” is for temperature, and “P” is for pressure. The pressure setting of the valve is usually 150 PSI and the temperature is 210 Degrees F. The pressure exceeding 150 PSI will cause the valve to open releasing the excess pressure maintaining a safe pressure below the 150 PSI working pressure. If the temperature exceeds 210 Degrees F the danger is far greater because the high pressure in the system will prevent the water from turning to steam so you can have an entire water heater full of water hot enough to convert to steam but not converting due to the system pressure. When the temperature exceeds 210 Degrees F the valve will open and flow water until the temperature drops. If the water heater were to burst when the water is overheated above boiling, the entire contents of the water heater will instantly convert to steam. This steam will expand 1,600 times its original volume of water. This is when the launch occurs.
The T&P Valve is a relatively inexpensive device that is threaded into either the top of the water heater or, the side of the water heater near the top. There should be a tube connected to the valve which may run down towards the floor under the older codes or, under new codes it may run to a place where it can drain without causing water damage. This tube must be allowed to drain dry by gravity. If water was not able to drain out dry the metal parts could corrode and cause the valve to fail. The water in the pipe could also freeze in colder climates causing an ice plug to form in the pipe. This pipe must never be plugged or the T&P valve will become ineffective greatly increasing the danger level.
The test is simple. On the T&P Valve there is a small handle that lifts a pin in the center of the valve. Before testing make sure you are in a safe position where you will not be struck by the hot water discharge, and that you know how to shut off the water supply to the water heater. You don’t have to turn it off but you need to know how to do it as the valve when tested may not reseat properly causing water to leak. If this occurs you will need to be able to shut off the water until the valve can be replaced. All you need to do for the test is lift the handle so the valve opens then release it so it closes. If the valve is frozen so it does not open or, does not close it should be replaced ASAP. Sometimes the valve may not set properly after testing. Try opening it and allowing it to slam shut several times. If this works the valve is okay. If it doesn’t it should be replaced. This test does not ruin a valve. If the valve fails the test it was already bad and was not offering the protection you need. Regular testing may actually increase the life of the valve. Test the valve a minimum of once a year.:wsmile:

 

[Tarhead]

Tarhead:
You answer your own question. If the water is still hot when the heater is turned off, then it still would have been hot without the thermostat cycling on, if the power is on. The meter does not spin until the thermostst clicks. What I am trying to say is, "This is a fictious money saver. If there is no load, because of modern insulation, then there is no money wasted." If heater was made before 1988, then the insulation is not as good. Is the supposed $4 monthly savings worth a case of food poisoning because the dishes were not sterilized?

OK, that makes more sense. I would estimate much more than a $4/month savings only using it for a few hours per day but what do I know? Still, the frugal German in me will keep turning the water heater to standby when we're away. Gotta reduce wear an tear.

I'm not so sure about the food poisioning concern. My dishwasher heats its own water but even so, it's not sterilizing my dishes. They're clean but not sterile.

 

[Gotcha6]

Drain pans are required here also. But if the pipe going to the heater corrodes out, it will cause a plastered ceiling with mineral wool insulation that is 50 years old to land on the hardwood floor. Ask my dad.
Expansion tanks are also required in commercial applications.
As to the original problem, I'm anxious to hear from Trent about what they found wrong with HIS water heater.......:wconfused:

 

[petebucy4638]

Pete:
Duke Power's website lists the following to reduce water heating costs: turn down the thermostats, insulate the heater and piping, minimize water use, fix drippy faucets, upgrade shower heads, and/or install a softener. They do not mention timers!
Are you saying that the small amount of water neccessary for the morning is all the hot water that is left? Either all the water is still hot or not. With the timer in the off position, incoming water mixes with the hot water and lowers the apparent water temp. Web research is vastly provided by the manufacturers and sellers of timers. They do not tell the whole story,
http://michaelbluejay.com/electricity/waterheatertimer.html . If you shut the heater down before it recovers from the evening load it will not be hot in the morning.

Unfortunately when energy-cost concerned people make changes they make many of them: timers, thermostats, insulation, new heat pumps, duct pipe insulation, windows, storm doors, etc. It is therefore very difficult to assertain the true savings credit!

I'm a home builder by trade. I went into business in 1979. Over the years I've had clients jump on just about every "energy-saving" bandwagon. I have had clients use everything from ground source heat pumps to radiant barriers. Some of them worked, others didn't, or at least we could not quantify their performance.

When it came to hot water, the best solutions that we ever found were: insulation of the tank and pipes and timers. Another good solution that really worked was the ECU. It took the waste heat from your AC unit and used it to heat he water in your water heater. It was so efficient that the first mod that the manufacturer had to use was to actually reduce the temperature to avoid scalding. These units were made in Longwood, Florida and they sold like hotcakes for many years. Florida Power used to offer a credit to builders who installed them that virtually covered the cost of the unit and installation. Today you never even hear the utilities talk about them. They are mostly an obscure technology that really did work but never caught on.

Using a timer on a water heater takes a bit of planning and discipline if you want to get the most out of it. Some people are very committed to that sort of thing, others aren't. I recommend setting the timer so that the water heater has enough time, after the last shower or use of hot water, to recover. Then in the morning the water will be reasonably hot enough to wash up without having to power the heater. If you are a family that showers, runs the dish washer, etc in the morning then set the timer to come on 45 minutes before you get up and then shut off sometime after your leave for work and school.

I have had clients who had me put their electric water heaters on a switch in the kitchen. They would manually turn the water heater on and off themselves.

There seem to be two energy-saving camps - the folks who want to save money and those who think that they are saving the planet. I have a neighbor who falls into both camps. Most of their energy savings come more from things like thermostat discipline and being aware of their energy usage than from the various technologies that they employ.

Pete

 

[cptully]

I just love my 1925 bungalow with utility basement with sump pump.... It's a real pain sometimes dealing with the sump, but if the water heater goes, the sump is there to catch it...