Good Morning: I don't know how to insert a picture into these posts. So the best I can do is to describe the RO system. I am just going to start from the holding tank. The holding tank is located 20 yards downhill from the house. Inside the holding tank is a submersible pump that is on a 60/40 pressure switch. The pump is activated based on the water use/pressure. Once activated, the pump, pumps the water up to the house where it goes through a Charcoal filter tank to remove excess chlorine and then into the house. The water heater is in the garage. The water supply line comes out of the wall and into a PVC tee which has an expansion tank on the top of the tee and the lower part of the tee connects to the cold input of the water heater. There has to be away to test the water supply under load to determine if: 1. Back siphoning is occurring. 2. The water supply to the house is insufficient under some load condition. But why it took 10 months to fail is what has me baffled. I feel like the water heater elements right now, burned out. Mark K.

Is this 'holding tank' the 1300 gal capacity one referred to in your earlier posts? Is it an open tank or under pressure? Is there no surge tank between the submersible pump and the house except the expansion tank at the water heater, which I assume is 1 to 5 gal capacity? (If there is no surge tank, say 40 gal., the pump must come on anytime a faucet is opened, right?)

What you need is a tank with a float switch that will prevent the elements from energizing when the water level drops....I would get a small tank and mount it just above the water heater with the switch installed...Something like this 5 gal expansion tank, you would have to tap water line in top out bottom with a float switch....

Totally agree with SE. Insufficient water supply will burn out the elements, although they will hold for a while. RO water is too slow for a water heater.

Somebody needs to invent a switch that will prevent the elements from energizing when they're not submerged.

Here's one.....

http://www.google.com/patents/US5388179

That should be standard on water heaters.

Patented in 95. Seems like it should be a no brainer. Wonder why they're not being used?

Hmm......................George Spector is quite the prolific inventor.

http://www.google.com/search?tbo=p&tbm=pts&hl=en&q=ininventor:%22George+Spector%22

So why haven't companies who make water heaters bought this patent and implemented this common sense solution? Answer they like to sell water heaters.

A simple water-detection sensor, like the ones they used on old car radiators, fitted above the critical point of the element would suffice. ('New' cars use detectors which give faults if there is insufficient antifreeze, so are not suitable for potable water).

What great common sense idea. Ever heard of planned obsolesce? Having to change out elements and thermostats keeps someone employed and sells water heaters.

Hello Everyone: Well that is nine hours that I will never get back. When I arrived at the house the first thing I checked was the upper thermostat. The thermostat reset switch was tripped. I reset and tested the heater elements for continuity using a fluke meter. The top element failed, the bottom element did not. In any case I replaced both elements with camco lime life elements that state they will withstand "dry-firing" and come with a lifetime warranty and all is working again. I was told that the 30 amp circuit was too small to support a water heater with dual 5500 watt elements because they would draw too much amperage for the 30 amp circuit. The manufactures manual states that 30 amps for a 240 circuit would support the water heater. Anyone know which one is right and which one is wrong? I still need to figure out what the root cause of all of this is. I will keep everyone posted to see what happens next. Mark K.

Seems like a 40 amp circuit would help a little.

Thank you for your response.

30 amp circuit #10 wire should be fine....That is standard....

The electrician told me he used number 10 wire when he ran the circuit. Can you tell me how I can tell if he used #10 wire? If he did not use #10 wire would that cause the element problems I just experienced after 10 months?

In normal operation, both elements are never on at the same time.

google "electric water heater sequence operation"

5500W/240V=23A

A 30 amp circuit (breaker & wire) should be adequate.

Thank you for your response. I am still trying to figure out the root cause of all this.

30 Amps is fine. Only one element operates at a time. As water is used, the top element comes on once it reaches it's temperature setting the lower element comes on and heats the entire tank.

Didn't catch where you live, but I would go with gas. Once I switched never had another problem.

Haven't turned the heater on for the past 7 mos. Even so, the water is still warmer than I like.

The house is in Port Charlotte Florida and unfortunately, Gas is not an option.

On cheap thermostats, the temperature settings can be turned up higher than the thermal cut-out will allow. Had the same issue - occasional tripping of the cut-out (manual reset required). Invested in a more expensive model, which does not allow the temperature to be set too high, problem solved.

The temperature on both thermostats is set at 140. I believe the thermal cut off for the upper thermostat is 160. This is the first time in 10 months the thermostat tripped and believe from what I found yesterday it was because the element went bad.

Units, please? Because 140 and 160degC are above the normal boiling temperature of water at 0barg.

I apologize - Fahrenheit 140F - 160F

Congratulations! Maybe the Camco elements will survive longer. As noted by others, a 30 A circuit is correct - only one element at a time is powered. As for figuring out the root cause, you seem reluctant to provide answers about your supply system that is quite likely the source of your problem. Incidentally, the reason you had to replace the submersible pump, as you noted in a recent post, could have been due to running dry - another possible clue that your storage tank is running out. Good luck.

A normal water heater (as opposed to a special very rapid recovery type which is rarely encountered) does not operate both elements at once. When tank is cold the top thermostat operates top element and disconnects bottom. After top reaches temperature the top is disconnected and bottom is heated.When bottom satisfied it goes off and on as needed unless top gets too cold (from heavy use) in which case top comes on for quick hot water. If you haven't been tripping breaker or blowing fuses the circuit is probably adequate. Only one 5500 watt (<23 amp) element operates at a time. If both operated at once 40 Amps would not be enough. Remember if you increase circuit size you must increase wire size or create a fire hazzard!

First, check that the foot valve(check valve) is working properly on the submersible pump.If it leaks, this could cause needless cycling of the pump. and could also drain the hot water tank between cycles.Install a check valve at the incoming water line to the house.This should be done anyway for safety, to prevent any grey or waste water from back flowing into the well during a power failure or foot valve failure.The check valve is required by code in most areas.

To check the foot valve, turn off all water outlets at the pump source.Let the pump run and cycle off.Observe the pressure gauge.Give it a few minutes and check it again.If pressure is dropping, the foot valve is leaking, or you have a leak in the piping inside the well.If so, don't panic.It may not be necessary to remove the pump.
A check valve at the top will work just as well, if there are no leaks in pressure line in the well.

Good luck,

OK - The well pump, pumps the ground water to the RO system, the RO system filters and treats the water and sends it to the holding tank.The submersible pump which sits inside the holding tank was replaced in June. The pump in the 1300 gallon holding tank is separate from the well pump. The problem with the water heater elements just happened again on 10/12/12. The submersible pump is on separate circuit and pressure switch 60/40. The pump comes on when the pressure in the line to the house drops below 40 psi and goes off when it reaches 60 psi. I doubled checked the pump operation coming on and going off as the pressure in the line changed while the tenants were using water. Thanks for your suggestions they may come in handy if the well pump starts to act up.

While the qualified electrician is checking the unit out, get the individual to look at the main distribution board for crosses between neutral and earth/ground, and rectify them. An element casing that is ordinarily connected to earth that has inadvertently become connected to neutral instead will suffer from electrolytic corrosion over time, regardless of the installation presenting several other safety hazards as well.

The technique involves isolating the distribution board from the supply, and measuring ohms between the neutral bar and the earth bar. Disconnect the "neutral" wires one at a time until the ohmmeter gives a radically different reading. The one that caused the different reading is the one where neutral and earth are crossed; that is the circuit that needs correction.

Good Morning: First let me thank you for your response. The "electricians" I have had to deal with are a challenge to say the least. Hazard of the area. So I have a couple of questions: Are you saying that I need to have an electrician check all the circuits in the main distribution panel or just the water heater circuit? Can you please explain what you mean by "isolating the distribution board from the supply" I am not an electrician, but I will have to explain this to them in excruciating detail while watching what they do. Regards - Mark K.

Neutral and Ground bars are connected together inside US residential electrical panels. Both connections to the heating element are "hot" voltages while the base and sheath of the heating element are at neutral/ground potential via conduction through the heater tank, ground wire connection, and pipes if they are copper or iron. From your description of the system it is highly unlikely that power faults are the cause of your problem.

As others have already stated, I think your well source, well pump, or the RO system cannot keep up with demand and your holding tank eventually falls below a critical level. Water heater element damage and holding tank pump damage will occur when operated without sufficient water present. With the generally low rainfall we had this year, I would not be surprised if your well source was the cause.

Good luck!

A1) All of them (been there/done it/secondhand T-shirt now on eBay).

A2) Turn off main isolator/pull main supply fuse(s)/whatever is needed to take live feed(s) off the board.

Thank you for your reply. I am going to try and find a competent electrician to perform the testing and I will let you know how it goes. Mark K.

If you find one, I'd suggest having him install a float switch on your holding tank to prevent the booster pump from running when the tank is empty below the pump suction. Your money would be better spent than chasing electric gremlins.

Why does hot water require a heater?

Because it would get cold if you do not heat it!

Why isn't it just called a water heater?

Because it also has to heat the hot water to keep it hot. I'd call it a water heater if all the water was cool to begin with!

Oh whatever! It heats water, so call it whatever you like!

Hot water heater is redundant, but frequently used. I don't know why. I prefer "water heater" or "hot water tank" when referring to this common home appliance.

5 Day - Update - No issues with the water heater after replacing the elements. Mark K.

Do your tenants say air comes out of the taps? Then the pump is running dry, and pumping air into the system, killing your element. An 'air eliminator' can fix that, I use one on my solar system.

RO water can be 'aggressive'. There is a test for that. It will eat all your metal in the system, tanks, pipes, elements. There are chemicals to balance this. Anodes help, check the anode in the hot water heater. If it is already corroded in a new heater, you have aggressive water.

I spoke to the tenants and asked them if air ever comes out of the taps before water does and they said no, however, I have to consider the source. Question when you say that RO water can be "aggressive" what does that mean? We test the water monthly, for TDS which has ranged from 100 - 220ppm and for PH has been between 6.8 and 7.2.

This link explains aggressive water fairly well, google the term for more.

I just caught the tail end of a Discovery Channel article on Reverse Osmosis, and aggressive water was being mentioned. I think they said to add calcium carbonate or such to the water to compensate for the alkalinity problem, or lack of alkalinity, whatever.

All I know is a local hotel had all their new copper pin-holed by aggressive water. Major pain in the pocket.

The link says that even when the Ph is 7, the water can still be aggressive, has to do with carbon dioxide content. PVC plumbing is not affected, but any metal is eaten.

Apparently, if you are getting green or orange stains in your sink, your water is aggressive. Worst thing is that it is releasing lead from old lead solder joints.

After replacing both elements on October 13th, our tenants called on Nov. 6th and complained that the water pressure was intermittently low and was not as hot and from his "experience" the top element had probably burned out. On Nov. 10th, we went down to the property and I checked both elements and thermostats with a volt/ohm meter and found no problems. We also had another Electrician come out and check the 240V circuit and the entire breaker panel and the incoming power from the service, no problems were found with the electric. Also on Nov. 10th, we had a GE service repairman out who checked the elements and thermostats and found no issues, but did replace the thermostats anyway. I adjusted the 40/60 pressure switch for the incoming water supply which was cutting off at 50 instead of 60. I checked the pressure at the house which remained at 50 psi after adjusting the 40/60 pressure switch. We tested the pressure and hot water by opening up the taps on all fixtures and showers for 5 minutes. There was no drop in pressure or hot water temperature. The common theme that everyone I have spoken to is that I need to replace the 5500 watt elements with 3800 watt elements. If I have more issues with the water heater that is probably going to be my next course of action. One final comment, some have suggested that air was entering into the Hot Water heater and that was the cause of the elements burning out. I don't believe that is the case based on the location of the elements in the tank and the fact that the tenant has never complained about "air spitting" out of the faucets which would definitely occur if their was that much air in the heater. My next visit, I am going to test the chlorine content of the water to see if my Charcoal filtration has broken down. Finally, I wish there was some way to post jpegs to this site because I have a couple of jpegs of the heater elements that I replaced. I will update again next month. Thanks for all of your help and suggestions and have a Safe and Happy Thanksgiving. Regards - Mark K.

You can or should be able to insert photos easily into posts.

Which browser do you use? Is there no green coloured camera icon on your message composition pane?

You may see improved performance from the system. 60 is a lot of pressure for the average pump. It may overheat trying to maintain that kind of pressure. I use 50 as a max personally. For any more than that, a high performance pump may be needed. For most situations, no more than three floors, 50 psi should do the job.