Q. My breaker box has 2 columns of breakers. The top breaker of each column is 100 amps.Does this mean I have only 100 amp service? The house is all electric, built in the early 1970's. I want to replace my tank water heater with a tankless electric. The tankless requires 200 amps.

A. The size of your service is determined by two things; the Main Disconnect (Breaker) ampacity, and the size of your service entrance conductors. For example; you could have a 200 amp panel and main breaker, but have only #6 AWG Service Entrance Conductors left over from an old 60 amp service. No matter what size panel you install, those number 6 conductors will burn up before they give you anything close to 200 amps. This is why it is important to know the actual electrical "load" required by your home. I have never, ever seen a residential appliance that requires 200 amps. Somehow, I think you have miss-stated or misunderstood something in the installation instructions. Most tankless water heaters I've seen require no more than a 60 amp, 240 volt feeder circuit. I've seen some as low as 40 amps. If the Manufacturer specifically states a 200 amp service is required to the dwelling, NEC 110.3(B) requires that a minimum 200 amp service be installed. If it is a recommendation, a 100 amp service may be okay, if you have a small house with no other electrical heating appliances (stove, furnace, cook top, oven) and no other large loads like a pool pump or spa. The only way to be sure is to hire a QUALIFIED, licensed electrician to do a load calculation for your home. Have him use the "Standard" load calculation from NEC Article 220, parts II & III; rather than the "Optional" method from part IV. The "Optional" method will often give you a lower figure for your required load, but the "Standard" gives a little more "room" for future additions to your electrical system. If you have a very large home, or, in your specific case, an "all electric" home [with lots of "add-ons" already (pool, spa, steam-room, etc.)], you may find a 400 amp service is required. This can be done with a "poor-man's 400", which is actually a 320 amp meter and two 200 amp panels. If you live somewhere that has adopted the 2008 NEC, you can install one of the newly allowed "super-panels" that will give you a true 400 amp service (with 84 breaker spaces). Incidentally, “Alvarz” is wrong; the smallest size service allowed on a new home (or installed as an up-grade) is 100 amp. I have seen residences that have 800 amp services (& nearly got lost trying to find my way out).

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Q. All electric house. I am considering adding on demand water heaters in two places. They cost at least twice as much as a tank type. Does an on demand burn the heater elements if the water is turned off? My tank type does burn out the heater elements if the water level drops below the elements in the tank. Also, is the on demand water heater repairable or would a person have to buy a new one in case of failure?

A. Good question. if your turning off the water, best to turn off the hot water heater also. all the point of use HW heaters I've worked on have a small quantity of water in them (4 oz) which stays 120 deg. as soon as there is a call for water, the cold water coming in triggers the stat to heat up the water.

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Q. It is time to replace it; how difficult will it be to put the new water heater in the garage which is attached to the house; but on the other side from where the current water heater is. And, does anyone recommend waterless heaters that give instant hot water?

A. It shouldn't be too difficult if you know how to solder and reroute the pipes. You may want to consider an insulating blanket for the water heater in your garage if you live in a climate that gets very cold in the winter- otherwise your gas/electric(depends on what kind of heater you have) bill will go up. If it is a gas heater be sure and double check for gas leaks when you reroute those too. I don't know much about the tankless, but know an acquaintance that is happy with hers.

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Q. I need to buy a new water heater and it has to be electric. The way I am reading the requirements to be eligible for a tax credit, the electric water heater has to have an Energy Factor of 2.0 or greater. I'm not finding any electric water heaters with an Energy Factor above 0.98 though. Any specific brands and model numbers of a qualifying electric water heater will be greatly appreciated. I appreciate the answers. Thanks for your help.

A. I couldn't find any, either. Nor could I find any tankless water heaters that are energy star compliant, so there goes that theory. If you can't meet the federal requirement, check with your municipality and state. Many have rebate programs of their own that will gain you real dollars instead of a tax credit.

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Q. We have solar water heating, but during off-peak hours, the electric water heater kicks in. ( Two hours in the evening and 1.5 hours in the early morning) The water is 140 degrees. Is this normal? I know the thermostat can be turned down on regular water heaters, but does it need to be this hot because of the solar? Water is scalding hot!

A. I would think it needs to be turned down. They recommend a maximum 125 to prevent scalding. I have only worked on a few solar systems but they all used a "regular" water heater to supplement the heat and store the warmed water. They were just plumbed differently. Usually they were set lower and on all the time. Lower so they did not try to heat the water going through the solar panels. But it is near impossible for us to tell you how yours is set up, the logic of the system. We know nothing about it, how it is plumbed, what controls, even how it works normally. I don't know if you have two tanks or one and the single tank is for both storage and heating. The main reason people turn up the temp is if the water is hotter you use less. So at 140 you might get three showers first thing in the morning, but at 125 degrees maybe only two without time in between heating water. I say try it. I can't think of any reason lowering the temp would be a problem, except for capacity as mentioned. Good Luck.

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Q. I just recently was fired from a plumbing and heating company and I am suing them for some other reasons. I was doing some research on the CT state labor site and I was searching the licenses and found that half of the techs we have are not licensed. I found one plumber who has no license and has worked on gas water heaters in the past. Is there anyway I can use this to get them in trouble? The company by the way, treats its employees very badly and overcharges the customers way too much.

A. I practice in Florida, not Connecticut, but I think that in most states only people with a license to work on LP lines can touch a gas line. While plumbers may understand "lines" their work sometimes has lethal results. I worked on a case where a well meaning plumber took out a woman's gas hot water tank (thinking it was the only gas appliance in the house) and replaced it with an electric one, at the customer's request. A week later the woman's stove would not ignite b/c the plumber (thinking there were no more gas lines in the house) turned off the gas at the tank and crimped the gas line to the hot water heater shut (or almost shut....) The lady goes out to the tank, turns her gas tank back on, gets her cake mix out, bends in her stove to light her pilot light and kaboom! The entire mobile home exploded and she went airborne, ending up in a yard of a home about 1/2 mile from her own. If that is the case in CT, working on LP lines w/o a permit can get them into big trouble. Instead of bad mouthing your old employer though why not go work for the competition and do good work for fair prices. The customers will follow.

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Q. I had a plumber come out and look at the water heater, but the sounds did not occur while the plumber was inspecting the water heater. The plumber turned the water heater down and said that he may have to come back out to "flush" the water heater if the sounds continue. Afterwards, I went several months without hearing any sounds at all. But, recently I have began hearing them again...any homeowners out there that can share their experience with water heaters? The water heater is only 2 years old.

A. I have to assume this is a gas water heater, although you don't mention which it is. The reason I assume that is that an electric unit only makes a sizzling sound, like bacon frying, when it's heating water. The gas heaters, if, as a couple of the previous answers have suggested, you live in an area of high calcium, lime content in the water, accumulate this lime in sediment form on the bottom of the tank over the years. When the burner kicks on and heats the water, it heats the calcium buildup too, when the calcium gets to a certain temperature it explodes like popcorn does under heat. The noise can be annoying if it's audible from the upper rooms, but it's seldom dangerous. If your unit is making that much noise, it's unlikely that you'll get much out of it by draining. The lime accumulates in large chunks in the bottom and the small spigots that the manufacturers put in most tanks won't let out much of anything bigger than a BB. I've taken chunks out of the element holes of electric units the size of a 50cent piece. If if gets too annoying, get a new water heater, and have the installer put in a 3/4" full flow ball valve as a drain. That will let out large chunks of stuff when it's drained. That shouldn't cost more than an additonal $10 - $15. There is no real way to effectively clean a serious lime sediment buildup from a gas water heater.

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Q. If I buy a Rheem/GE water heater at Home Depot, I can compare a bunch of different water heaters there, and choose which one I like best according to its features, such as how fast it heats the water, how good its warranty is, etc. But if I buy a water heater from a plumber, I just get a total cost including installation, and no information at all about what water heater I'm getting. Even if the plumber gives me the model number of the one he plans to install, it's different than the model numbers at Home Depot. For example, some of the model numbers at Home Depot start with 42V but the ones from the plumber seem to start with 82V. Are 42V and 82V equivalent, or is 82V old, or what? Oops. The 82V is electric vs gas. That's why I couldn't find it. The plumber made a mistake when he gave me the brand and model.

A. A good plumber should be able to give you the years of warranty...the btu recovery rate name/size and all. The brand name should have a web sight and his model number should be in their info. Match the warrenty years and the BTU recovery rate. IE.. A 40 gallon heater with a 12 year warranty and a 37,000 BTU recovery.

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