# WATER HEATERS THE HOME TYPE, OR WHY DO I ASK THESE QUESTIONS



## Madman (Jan 5, 2008)

If you have a 50 gallon gas fired hot water heater, which of the two scenarios would lead to a bigger savings in your monthly gas bill? 

*Keep the thermostat higher*; In this scenario when hot water is called for, taking a shower for example, reason would have it that less hot water is drawn from the tank, since you wouldn't want to scald yourself. Thus less of the stored hot water is being used. However, the water that is stored in the tank will need to be kept at the higher temperature 24/7, or all of the time.

*Keep the thermostat lower*; In this scenario when the same shower is being taken more of the water for the shower is being drawn from the tank, and less from the cold water supply. The stored water is not being kept very hot using less gas in the same 24/7 time period.


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## NTCGRR (Jan 2, 2008)

Another thought, i work out doors alot in winter, when I get home I want a warm house and hot shower. thus I will pay the price. Thus we also use fire wood.


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## Greg Elmassian (Jan 3, 2008)

Keep thermostat lower. 

In a perfect world the 2 would be equvalent, IF there was no heat loss through the boiler jacket, and perfect combustion, i.e. all of the gas burned went into heating water and not out the flue. 

But we are not in a perfect world, you see even Marty does not have $15 rollers for his new $800 brass loco! 










So, keep the thermostat lower... in fact take cold showers! 

The answer is right, the joking remarks are just that, jokes... 

Regards, Greg


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## Madman (Jan 5, 2008)

Posted By Greg Elmassian on 12 Oct 2009 06:40 PM 
Keep thermostat lower. 

In a perfect world the 2 would be equvalent, IF there was no heat loss through the boiler jacket, and perfect combustion, i.e. all of the gas burned went into heating water and not out the flue. 

But we are not in a perfect world, you see even Marty does not have $15 rollers for his new $800 brass loco! 










So, keep the thermostat lower... in fact take cold showers! 

The answer is right, the joking remarks are just that, jokes... 

Regards, Greg 


Greg, I thought we were in a perfect world. Are you in another world? Apparently MLS.com is not in that perfect world at the moment. I can't get the text to come out all one size


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## pfdx (Jan 2, 2008)

Regardless of what temp you decide to set the heater at, go out and get a insulated wrap for the tank and insulate your pipes. It's simple, cheap, and it saves money. Insulate the cold water line about four feet feeding it too.


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## John J (Dec 29, 2007)

Kepp the temp high....The hoter the water the better the dishwasher works. Then you don't waste water washing the dishes before you put them in the dishwasher. 
O convert to Eletric and put a time clock on it. set temp high and only heat water between 4 and 7 in the morning and 6 to10 at night.


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## Madman (Jan 5, 2008)

Posted By John J on 12 Oct 2009 07:19 PM 
Kepp the temp high....The hoter the water the better the dishwasher works. Then you don't waste water washing the dishes before you put them in the dishwasher. 
O convert to Eletric and put a time clock on it. set temp high and only heat water between 4 and 7 in the morning and 6 to10 at night. 



Which opens up another issue; dishwashers. Our latest and supposed to be greatest dishwasher turns out to be our worst performer of the three that we have owned in the last 30 years. The first was second hand, Kenmore. The second a new lower end Kenmore. And our present one a near top of the line Kitchen Aid. One of the suggestions was that we needed to keep the hot water temperature high so that the dishwasher would work properly. Never had that problem with the run of the mill washers. More on this later. SWMBO is calling


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## Greg Elmassian (Jan 3, 2008)

Our new dishwasher heats the water as it sees fit. More efficient than raising the hot water temperature for the whole house. 

What does your local utilities company say? 

* http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=13090*

Lower the temp.

Regards, Greg


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## Madman (Jan 5, 2008)

I believe that all dishwashers heat the incomming water, which is already the hot water supply. The people at kitchen Aid told us that the newer dishwashers don't heat the water as much as the older models did, no matter what manufacturer. The reason..................the newer models are "greener". So where is the savings when the hot water supply needs to be kept higher?


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## pimanjc (Jan 2, 2008)

Had you considered the small "instant hot water" heater units? I suspect this would be the most ecconomical after the initial cost. I have no idea how long it would take to amortize the initial installs though.

JImC.


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## Richard Smith (Jan 2, 2008)

Posted By Madman on 12 Oct 2009 08:02 PM 
I believe that all dishwashers heat the incomming water, which is already the hot water supply. The people at kitchen Aid told us that the newer dishwashers don't heat the water as much as the older models did, no matter what manufacturer. The reason..................the newer models are "greener". So where is the savings when the hot water supply needs to be kept higher?

Our Kitchen Aide has a temperature selector on the front of the door to set temps higher or lower. I believe yours should too.


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## ralphbrades (Jan 3, 2008)

There are times when I read these Off Topic threads and I really have to go *"WHAT?!?!?!?"*

Here in the UK power is not cheap. Here we have gone to point water heaters called "combis" that simply heat the water you use -there is no large hot water tank . Most homes have electric showers -which again heat only the water that is used. I have never had a washing machine that does not have simply a cold water feed and heats the water inside it. As to a dish washer, well I have never had one of those, like most of the UK we use a sink, a bottle of washing up liquid, a draining board and tea towel...


But my advice would be to turn your thermostat down to 45 degrees C (hand hot) and lag as much of the pipework as possible -and this is after having completely insulated the hot water tank. Your next port of call is to investigate local point water heaters... 


regards

ralph


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## Randy Stone (Jan 2, 2008)

The instant hot water heaters are going to be the most economical yes, but like most energy savings items, unless the hot water heater you have now needs replacing, it will take years to recover the cost of the units. Only after the untis have paid for them selves will you start saving money. 

Using a time to limit the time the hot water heater is heating water will save the most money with the least expeditures up front. 

As for using the Dish Washer to wash the dishes, isn't that why we had kids?


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## Torby (Jan 2, 2008)

Had one of those instant ones in the shop, and I loved it. It was stone cold, off, using NO power, until you wanted hot water. Then it was there instantly, as much hot as I wanted. The trick to using it was to turn the hot water on full and adjust the temperature with the cold. That might confuse some of the thermostatic type shower controls. If you turned the hot down a little, the water got HOT!


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## George Schreyer (Jan 16, 2009)

Keep it lower. Keep going lower until you actually run out of hot water at times. This reduces the standby heat losses from the heater and the piping which is a significant portion of the total. When a heater is properly insulated, just the pilot can keep it fairly warm when no hot water is drawn. This keeps the burner from igniting so often. 

MOST dishwashers will use the dryer element to heat the water in the tub when needed. Some heat on several cycles, some heat on only the last rinse cycle to reduce spotting. 

In-line heaters are very common around the world but they have a significant drawback. Their heat regulation is poor. This is because most of them are either on or off. The temperature at the outlet depends on the inlet temperature and, most important, the flow rate. If you are trying to set the temperature of a shower, you can often set it with the hot tap alone. High flow reduces the temperature. If it is too hot, you add cold water. If it is STILL to hot (this happens) then you reduce the hot flow and the temperature of the hot water rises. In those cases, it is REALLY hard to get it right. 

If the unit cycles during use, the hot water will go on and off while you are taking your shower, and you'll be chasing the temperature all the time. This can be a literal pain (or scalding) in the backside. If you get one, spend the extra money and get the models with an actual feedback loop such that it controls the outlet temperature by itself.


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## George Schreyer (Jan 16, 2009)

Ralph, instant hot water heaters are rare in the states and even the "cheap" ones are VERY expensive. Further, US power is at 110 VAC, most circuits are limited to about 1500 watts. This is marginal for an electric hot water heater. My house has 220V at the panel, but it isn't wired anywhere to the house. Most US addresses have natural gas so that the cost of heating water is quite a bit lower than where there is no gas. I have never seen a clothes washer that heats its own water. At least most dishwashers do. 

Life is different all over.


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## Greg Elmassian (Jan 3, 2008)

When my house was being built, it was fitted with a recirculating hot water system, i.e. the furthest point has a pipe coming back to the hot water heater and a small pump. This gives you hot water to the tap within 4 seconds in all rooms. But, I reasoned I could get more heat loss, so I insulated all the hot water pipes, every last inch of them. 

That, and a more efficient hot water heater, and an insulated garage helped (hot water heater in garage). Now, sometimes I have to run the cold water a bit to get it cool, ha ha! 

Regards, Greg


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## John J (Dec 29, 2007)

As I understand it. The At Point instant water heaters require their own dedicated circut. Also heavery wire for their curent draw. About the only time they are cost effective is in new homes where the proper wireing can be run at time of installation. 

This was explained to me by a local contractor. 

I was looking for a small water heater to put under the sink for the Dishwasher. The Idea was to keep a small amount of water hot for the dishwasher. 

I could not find one small enough at the time. That is when I thought of the instant water heaters. 

That is when the Contractor gave me the insite .


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## Randy Stone (Jan 2, 2008)

Ha, my house was replumbed before I bought it. In Florida where most homes are built on a cement slab, this means the hot and cold pipes all are located in the attic. So in the summer especially, you don't even need to turn the hot water on to wash your hands or wash the dishes in the sink. The negative part is if you want cold water, you have to wait for all the hot water to clear before you have cold water. Thankfully we have filtered cold water from the fridge.


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## ralphbrades (Jan 3, 2008)

This is our Washing Machine. (Our previous one was a Zanussi). 

http://www.bosch-home.co.uk/our-pro...rce=browse 

This is our 35kW "combi". 

http://www.glow-worm.co.uk/products/flexicom_cx.asp 

This is the shower. 

http://www.showerstoyou.co.uk/product_desc.php?id=1575 

I think the problem here is one of philosophy rather than voltage... As to the argument that replacing a hot water boiler with a combi would only make sense in the long term is -that I have to disagree with. Not only does heating wastefully 50 gallons of water, when you only need dribs and drabs make poor thermodynamic, (not to say monetary), sense -it is also very inefficient... 

regards 

ralph


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## Greg Elmassian (Jan 3, 2008)

Yes, but your electric heat is less efficient in most cases than gas, or at least more costly. 

That's why we in the US have gas water heaters, gas ranges, gas ovens, gas furnaces, gas clothes dryers whenever possible. 

The latest gas appliances are very efficient. 

Oh, I also have a gas patio heater... ;-) 

Regards, Greg


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## Ted Doskaris (Oct 7, 2008)

When my loft project was being built, I had to vacate the garage of everything, including the clothes washer and dryer. So I temporally moved them out to my back yard deck. The washer was plumbed for just a cold water feed, so I "Y" connected its hot & cold inlets. Assuring that the detergent used was suitable for cold water use, it worked well.

During the construction, the decision was made to eliminate the traditional tank type hot water heater that had been in the garage, and replace it with a Takagi brand tankless gas fired hot water heater - but now relocated up in the loft above the garage. 
The contractor chose to use 3/4 inch water lines to / from the Takagi for flow loss considerations, but in retrospect this was not the best thing to do as the volume of the water in the larger pipe size when added to the greater distance the heater now is from its end use points resulted in an excessive time it takes to get hot water. 
So for the dishwasher in the kitchen, it would never receive any hot water until it went through more than the first cycle.
However, and fortunately, the dishwasher (a Maytag) has its own heating element to heat the water like so many do - though intended to raise the water temperature to a higher than the normally supplied hot water temperature so as to achieve a more sanitary dish washing result.

Another thing I noticed about the tankless heater is it will not initiate a "burn" condition with a minimum water flow. So if you are use to mixing hot & cold at the tap to obtain a desired temperature result and then progressively turn down the mixed flow volume, the tankless heater will stop putting out hot water. Since the Takagi I have includes a remote temperature control, I just reduce the water temperature from its 122F degree setting I typically use to 102F degrees, and for example, I can then fill the bath tub at a slow flow with the hot water only faucet.

-Ted


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## Les (Feb 11, 2008)

Madman,

I just replaced my hot water heater after 40 years. I wanted the 'at point of use' system, but it was staggeringly expensive to install.

In general terms, according to our local gas company, keep your water heater temperature low to save energy, they said. My new one has an energy star rating, but since I'm on SS I can't get the write-off the state pays.

One trick, if you can learn to do it, is to wash your hands in cold water. (It only hurts for a little while.)

One thing not mentioned is that when you do turn on a hot water tap, cold water from the Mains gets dumped into the reservoir of hot water, diluting same, I'm told.

I'd be very thoughtful about using a timer on a hot water heater, because of the lag time (or lead time, depending on how you want to look at it) might be longer than you're willing to wait for a hot shower, for instance.

A sure-fire money saver for those with gas heat is a wood stove or fireplace, but a *lot* of thought needs to go into that decision, first. Curiously, our homeownen's insurance is cheaper for a fireplace than a wood stove. A wood stove is much more efficient, plus you can keep a kettle on top for 'instant' hot water.


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## George Schreyer (Jan 16, 2009)

that's another issue with instant heaters, when the flow gets low enough, they shut off. The gas fired ones tend to require more flow than a small electric one. 

There are 110 volt heaters available here, but they are expensive and are good for only one faucet or a dishwasher. I investigated that many years ago when I was reworking my hot water system. At the time, my dishwasher was an older one that did not preheat the water at all. I found it was less expensive to replace the whole dishwasher with one that did pre-heat than to buy and install a small instant heater. Since I didn't need the instant heater for the sink, it would only feed the dishwasher. The amount of power consumed to heat the water in the dishwasher would be the same either way so that there was no economic reason to install it. 

When we were in Ecuador, one of the student facilities (an old monastery) had showers with only cold water going to the shower head. Inside the head was a small electric heater. The temperature was adjusted by changing the water flow. In the hacienda where we were staying, they had electric tank type heaters which they had set to scalding. It was really hard to set the shower to get a reasonable temperature because the hot flow had to be set to almost off and then ANY change in water pressure at all resulted in dramatic swings in temperature. This is another reason to set the temperature of a tank type heater to the lowest tolerable, you can turn the hot water flow on and expect that the temperature will remain fairly stable. 

Here in CA where gas is cheap (relatively) and electricity can be expensive, it costs 3 to 4 times as much to heat with electricity over gas. Gas tank type water heaters are fairly inexpensive, as compared to the gas instant types (which cost over a grand the last time I checked many years ago). Also a properly strapped gas tank type water heater can serve as an emergency water supply if an earthquake breaks some water lines.


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## Torby (Jan 2, 2008)

So, with all this input, have you decided?


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## JEFF RUNGE (Jan 2, 2008)

Ralph, with electric at 8 cents per KWH it will take the rest of my life to recover the cost of those units. 

Now having said that the cost of energy is going to go up, based on the panic of global warming with is actually global cooling? which will cost us more to heat our homes in our new "global warming" cooler global climate. Further slowing the non existent economic recovery. Not to worry I won't have to pay for it. They are going to fine me then throw my ass in jail because i can't afford health insurance now, never mind when it increases buy 4 thousand dollars a year. Once I'm incarcerated hot water, food, lodging, health care, and the fitness club are all free, why I'll even have free cable TV. 
Note: The second part of this post is done for humor !!!


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## NTCGRR (Jan 2, 2008)

I am always amased at threads like this. I do have a set of rollers, but where are they is the Q.?


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## Madman (Jan 5, 2008)

Posted By Torby on 13 Oct 2009 04:01 PM 
So, with all this input, have you decided? 


I am at such point as to now have possibly so much information, that I have completely forgotten what, why and where this thread is aboput, why it exists, and where it was originated. Did I start this never ending story?

Marty, I hope you find your rollers. It seems that more souls than you are worried about them.


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## Greg Elmassian (Jan 3, 2008)

Marty has been giving me some not so gentle ribbing lately, so my much milder jibe about rollers is not worrying, it's just gentle retaliation. Much more gentle than "I know you're always right Greg".

By the way, you did start this thread Dan, just to help your memory ha ha! Why, only you can tell. Did you turn your water heater down yet?









Regards, Greg


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## nkelsey (Jan 4, 2008)

It was time to replace my Forced Air and I got a package deal including a "on-demand" tankless gass water heater. It cost about $3500 installed, but I am looking at $1500 Energy tax credit and my gas use has gone down about 20%. The real bonus, I can get a hot shower after my two daughters have showered!!!!! I can run showers, dishwasher and washer at the same time and all get hot water, do not regret the change one bit.


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## ralphbrades (Jan 3, 2008)

Jeff...

My last electricity bill was £87.89p for 674 kW Hours or £0.13p per kW Hour which equates to *20.4cents per kW Hour*, (and prices have come down...) It paid for itself in under 9 months.


regards

ralph


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## Tom Thornton (Nov 18, 2008)

One thing that no one has asked is why do you have a 50gal hot water heater. Do you have a huge family and feed people that come to the door?
A 40 gal gas water heater will save you I would think. Why heat all that water?


Tom Thornton


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## Schlosser (Jan 2, 2008)

One thing that has been overlooked is the safety thing. My oldest brother had to spend some time in an 'old folks home'. He complained about the tepid hot water, about 100 degrees or so. He was told it was because many elderly people get confused and when the water was too hot, turned it hotter - the opposite direction from which it should have been turned. So keeping the temperature low, lowered law suits, too.

Young children also don't have the experience to know which way to turn things and end up getting scalded by hot water.

And then there was the sad case of the young mother here in Austin who was taken into custody because she reprimanded her kids by setting them in scalding bath water.

Hot water that can scald is just too flamin' hot.

Art


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## RimfireJim (Mar 25, 2009)

Posted By Les on 13 Oct 2009 02:43 PM 


One thing not mentioned is that when you do turn on a hot water tap, cold water from the Mains gets dumped into the reservoir of hot water, diluting same, I'm told.

I'd be very thoughtful about using a timer on a hot water heater, because of the lag time (or lead time, depending on how you want to look at it) might be longer than you're willing to wait for a hot shower, for instance.

A sure-fire money saver for those with gas heat is a wood stove or fireplace, but a *lot* of thought needs to go into that decision, first. Curiously, our homeownen's insurance is cheaper for a fireplace than a wood stove. A wood stove is much more efficient, plus you can keep a kettle on top for 'instant' hot water.

On all "tank" water heaters, whether they be gas, electric, or solar, the cold water inlet pipe goes to the bottom of the tank and the hot water outlet comes off the top of the tank. There is a temperature gradient in the tank, just like in a lake, because the denser cold water sinks to the bottom. There would be no way to get hot water out of the tank without letting cold water in, given that the tank is a rigid shell that is completely full (unlike a well water supply pressure tank).

I've had a timer on my electric water heater for twenty years now and it works just fine. I set it to turn the heater off _before_ pre-bedtime showers, since there is still plenty of hot water in the tank for the amount we will use and there is no point heating up the replacement water just so it can cool off again overnight, and I set it to turn on about a half-hour before morning showers, which is plenty. That yields about 8 hours every day that I'm not trying to maintain the temperature of the tank just because of heat loss. To those who think that somehow it takes more energy to reheat the water in the morning than it would have taken to keep it hot all night long, I use an analogy of a bucket (tank) with a hole (heat loss) in it. The hole is in the bottom of the bucket, so the fuller the bucket is, the faster the water leaks out (heat loss is proportional to temperature difference). Does it take any more water to fill up the empty bucket in the morning than it would have taken to add continuously to balance the leak? No, it takes less, and the longer the bucket is empty (heater off), the greater the difference.

Many fireplaces cause a net heat _loss_, because they use room air for the combustion - air which is replaced by cold air drawn in from outside. You may feel warm in front of it from the radiant heat, but the rest of the house may be getting colder. Inserts can increase the amount of energy extracted from the fire, but the real improvement comes from having a dedicated cold air supply for the fireplace or stove.


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## Torby (Jan 2, 2008)

Young children also don't have the experience to know which way to turn things and end up getting scalded by hot water. 

I still do that. Had my own eruption at the Botanic Sunday. I filled up the bucket, then turned the knob the wrong way.


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## Les (Feb 11, 2008)

Posted By RimfireJim on 14 Oct 2009 02:38 PM 

A sure-fire money saver for those with gas heat is a wood stove or fireplace, but a *lot* of thought needs to go into that decision, first. Curiously, our homeownen's insurance is cheaper for a fireplace than a wood stove. A wood stove is much more efficient, plus you can keep a kettle on top for 'instant' hot water.

On all "tank" water heaters, whether they be gas, electric, or solar, the cold water inlet pipe goes to the bottom of the tank and the hot water outlet comes off the top of the tank. There is a temperature gradient in the tank, just like in a lake, because the denser cold water sinks to the bottom. There would be no way to get hot water out of the tank without letting cold water in, given that the tank is a rigid shell that is completely full (unlike a well water supply pressure tank).


I didn't know that the cold water was introduced at the bottom. Live and learn,Huh?




Many fireplaces cause a net heat _loss_, because they use room air for the combustion - air which is replaced by cold air drawn in from outside. 

Yes, a good point. Having had a fireplace for almost 30 years with outside combustion air provided, I'd forgotten to mention that (outside combustion air) as a 'given'. W/o that, and adequate independently operated dampers, blowers and fireplace doors, a fireplace is a heat pump to the outside world.

Glad you emphasized those facts.

Les


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## Les (Feb 11, 2008)

Posted By Torby on 14 Oct 2009 03:50 PM 
Young children also don't have the experience to know which way to turn things and end up getting scalded by hot water. 

I still do that. Had my own eruption at the Botanic Sunday. I filled up the bucket, then turned the knob the wrong way.






I hate it when that happens.


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## Madman (Jan 5, 2008)

Posted By Greg Elmassian on 13 Oct 2009 08:24 PM 
Marty has been giving me some not so gentle ribbing lately, so my much milder jibe about rollers is not worrying, it's just gentle retaliation. Much more gentle than "I know you're always right Greg".

By the way, you did start this thread Dan, just to help your memory ha ha! Why, only you can tell. Did you turn your water heater down yet?









Regards, Greg 

Memory? I had turned the water heater down a few days before I started this thread, then got to thinking about it as I had in the past from time to time. So I figured with all of the brainy people here, I might put the question to them.


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## Madman (Jan 5, 2008)

Posted By Tom Thornton on 14 Oct 2009 07:02 AM 


One thing that no one has asked is why do you have a 50gal hot water heater. Do you have a huge family and feed people that come to the door?
A 40 gal gas water heater will save you I would think. Why heat all that water?


Tom Thornton


Very good question Tom. When I first bought the house in 1974 it was recomended that I install a fifty gallon HWH. As we had planned on starting a family, we were told that with kids taking showers and everything that goes along with kids it seemed like a good idea. That water heater lasted 30 years. So when I had to replace it, I did so with the same size heater, even though the kids are all out on their own. I probably could have gone to a smaller one, but why change a system in mid stream. the tankless hot water heaters look like the wave of the future. When our present HWH dies I will most likely go with one of them.


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## Les (Feb 11, 2008)

When our present HWH dies I will most likely go with one of them.







You are planning on immortality??









Ol' Vulp


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## Dean Whipple (Jan 2, 2008)

I have (2) gas tankless Aqua Star model 125 Water heaters I installed 20 years ago when I built our house.... 
I have (4) people living here and other than in the colder month's when we use the FAU my gas bill always has been at the minimum/basic amount..... 
One thing to remember when costing a tankless water heaters is that because they do not store the hot water they do not wear out (build up calcium) they do need to be replaced the only maintenance they need is to have a valve rebuilt every 5 years or so, the rebuild kit costs about $22.00 and takes about 20 minutes to replace......


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## Madman (Jan 5, 2008)

Posted By Les on 14 Oct 2009 06:53 PM 

When our present HWH dies I will most likely go with one of them.







You are planning on immortality??









Ol' Vulp










Let's see, The first HWH lasted 30 years. The year it died and was replaced by our present HWH was 2004. So if the present one lasts as long I'll only be 87. A spring chicken


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