Jump to content
IGNORED

Need to Replace Electric Hot Water Heater-Opinions?


RSTDdog

Recommended Posts

Found HWH leaking in the garage this morning. Its the original from the house and 7 years old. Single element 40 gallon electric. Supplies sufficient hot water for our needs (2 adults only) Any options that would provide any real savings in electricity, or just go out and buy the same type??

 

Thanks

Link to comment
Share on other sites

Guest scarylarry

Sure the pop off valve is not leaking?

 

Look at the tankless heater closely they are pricey and the difference made ttake time recoup..

 

Also check and make sure you have the amps for it the tankless

Link to comment
Share on other sites

Sure the pop off valve is not leaking?

 

Look at the tankless heater closely they are pricey and the difference made ttake time recoup..

 

Also check and make sure you have the amps for it the tankless

 

Yeah not that lucky, the pop off valve is fine. WH cabinet is full of water when you take the access panels off. It leaked a little bit a year ago and fixed itself.

 

The tank less has the benfit of allowing me to put my air compressor where the current unit is. WH is right next to the breaker panel so upgrading for a tankless would be easy. Not sure tankless is in the budget though, even if the payback is there.

 

Relocating HWH to the attic would provide the same space savings as tankless but at lower cost. Working in the attic in Florida anytime between now and November is another matter.

 

Thanks for the input everyone.

Link to comment
Share on other sites

I put a Bosch tankless in - bought it from Granger and it does save a ton on electric. Just need to make sure you have at least 3 empty circuits in you service panel. You might be able to get away with a 2 circuit tankless but 3 would be a long term savings.

Link to comment
Share on other sites

I have installed many tankless for customers, gas and elec. But you MUST be able to power them. Simple physics, a tank uses low power for a long time. Tankless uses high power for a short time.

 

For an electric tankless, it takes (3) circuits, each of which is double pole. So, you must have (6) spaces in your panelboard. You must also have the amps available.

 

I have sold electric tankless for new construction, but have never been able to sell one into an older home. They almost all need a panel upgrade, which throws the price out of the roof.

 

Gas tankless can be affordable in older homes, if they are not located too far away from the meter. In existing construction, they usually require a dedicated line to the meter because the existing line is not large enough.

Link to comment
Share on other sites

If I ever change out my hot water heater, I am going with a tankless unit. My neighbor has one and it reduces energy by a lot.

 

:farmer:

 

That is exactly what I was thinking. The electric tankless are somewhat cheaper now than when they first came out. If you think of it, the tank heaters are keeping that water hot at all times. The tankless only heat what you need. A friend from the local channel CB here channel 23 we monitor. He did this about two yrs ago and says his electric bill dropped $50.00 per month. The water is set at a pre determined degree and you do not need to add cold water to it to get the right temperature when showering. You turn on the hot water and go. That is what he is doing, and he is one of those people who always unplug anything that is not being used. He loves to save that way. He said that the power company came and checked his meter to see if something was wrong with it. They did change it out and his bill was still the same. He said it was the tankless heater saving him so much money.

:thumbsup2:

Fuzzy

Edited by FuzzyRSTD
Link to comment
Share on other sites

One of the major drawbacks of on demand water heaters is volume.

 

An average residential 50 gallon tank type WH has (lets say) an 80 gallon first hour rating. This includes not only the water that is sitting in the tank hot, but also the water that is being heated as it is being used.

An tankless unit of the same design use, may have an first hour rating of, lets say, 35 gallons.

 

The big difference is that where the storage tank water heater is not going to give you much of anything in the second hour, the tankless will keep on putting out its 35 gallons of hot water per hour, every hour.

 

If you use a little hot water at a time.....only one shower, or only do laundry, or only do dishes, a tankless may satisfy your needs. If you shower, do laundry, and dishes all at the same time (your household not you specifically) a tank type if the one for you.

 

As a Master Plumber/Plumbing Inspector for several jurisdictions in my area, I see very very few tankless water heaters going in. They just don't supply the large volume of water/short duration used by most people.

Link to comment
Share on other sites

One of the major drawbacks of on demand water heaters is volume.

 

An average residential 50 gallon tank type WH has (lets say) an 80 gallon first hour rating. This includes not only the water that is sitting in the tank hot, but also the water that is being heated as it is being used.

An tankless unit of the same design use, may have an first hour rating of, lets say, 35 gallons.

 

The big difference is that where the storage tank water heater is not going to give you much of anything in the second hour, the tankless will keep on putting out its 35 gallons of hot water per hour, every hour.

 

If you use a little hot water at a time.....only one shower, or only do laundry, or only do dishes, a tankless may satisfy your needs. If you shower, do laundry, and dishes all at the same time (your household not you specifically) a tank type if the one for you.

 

As a Master Plumber/Plumbing Inspector for several jurisdictions in my area, I see very very few tankless water heaters going in. They just don't supply the large volume of water/short duration used by most people.

 

Straycatt please check your wording here again. I am confused. Thank you, James.

Link to comment
Share on other sites

3 things you need to think about.

  1. What is the average temperature of the source water. a well or lake may be colder than a municipal supply.
  2. how many outlets or taps are used at once (your Gal per min demand)
  3. what is the temperature increase you need. (difference from the source temp to the desired hot water temp.)

A tankless units are generally rated for a "X" temp. INCREASE at "Y" gal/min

 

Assuming a tankless unit will provide 90* ( degree) increase at 2 gal per min. (a single shower will use 2 gal per min)

IF your source water is 45* (from a well or lake) you can heat 2 gal per min up to 135 degrees.

 

But if you need 5 gal per min, that same unit may only provide a temp increase of 50* ...so 45* +50* means your hot water will only be 95* which is not hot enough for most folks.

 

Now the OP was in Florida....so assuming the water is a constant 55*-65 * you need less "boost"

 

I'm not saying these numbers are accurate...but thats the jist of the way it works.

Edited by Trader
math....DUH
Link to comment
Share on other sites

Straycatt please check your wording here again. I am confused. Thank you, James.

 

 

Ok, lets try it this way.

 

A tank type water heater will put out a lot of hot water for a short amount of time, and then it's done for a while. A tankless water heater will put out less hot water, but will do it forever.

 

The tank type has lots of time to heat your water, the tankless doesn't. Because the tankless has to heat the water "on demand" it does two things. The first is to be able to generate enough BTU's to heat the water and still function within the design limitations of existing construction. The second is that it limits the water flow so it has time to be heated.

 

Where the standard tank water heater may be 30,000 BTU's, the tankless may need 70,000 BTU's to do the same thing.

Link to comment
Share on other sites

3 things you need to think about.

  1. What is the average temperature of the source water. a well or lake may be colder than a municipal supply.
  2. how many outlets or taps are used at once (your Gal per min demand)
  3. what is the temperature increase you need. (difference from the source temp to the desired hot water temp.)

A tankless units are generally rated for a "X" temp. INCREASE at "Y" gal/min

 

Assuming a tankless unit will provide 90* ( degree) increase at 2 gal per min. (a single shower will use 2 gal per min)

IF your source water is 45* (from a well or lake) you can heat 2 gal per min up to 135 degrees.

 

But if you need 5 gal per min, that same unit may only provide a temp increase of 50* ...so 45* +50* means your hot water will only be 95* which is not hot enough for most folks.

 

I'm not saying these numbers are accurate...but thats the way it works.

 

 

Very good explanation.

 

Let me add, if you want to increase the temp rise, you can either increase the BTU's or slow the water down so it spends more time being heated or reduce the amount (volume) of water being heated.

 

All of these things have a bearing on real world use.

Link to comment
Share on other sites

Ok, lets try it this way.

 

A tank type water heater will put out a lot of hot water for a short amount of time, and then it's done for a while. A tankless water heater will put out less hot water, but will do it forever.

 

The tank type has lots of time to heat your water, the tankless doesn't. Because the tankless has to heat the water "on demand" it does two things. The first is to be able to generate enough BTU's to heat the water and still function within the design limitations of existing construction. The second is that it limits the water flow so it has time to be heated.

 

Where the standard tank water heater may be 30,000 BTU's, the tankless may need 70,000 BTU's to do the same thing.

 

Thanks ....

Link to comment
Share on other sites

Thank You for all the input and responses. Just back in from working. Don't have enough spaces in the panel for a Large tankless (don't have enough money either).

 

Replaced it with another conventional 40 gallon heater. I did have room and moved it into the attic though. Since my attic is easliy 120 degrees or more probably 10 months out of the year, I figure up there it may not run as much. It will still have to heat water for showers and laundry but it may not have to come on to keep it hot while not in use. Thats my theory any way. Also frees up a nice space for my 60 gallon Air Compressor and you jsut can't put a value on that.

 

I noticed somone said they ( or someone they know) saved $50.00 a month switching to tankless. Thats $600.00 a year. The estimated operating cost posted on the heater I just bought is only $508.00 a year. assuming the basis for that is similar to my usage, If I unplugged it and took cold showers I could only save 42.00 a month. So how much do I really save with a tankless? All things being equal, what uses more energy taking a twenty minute shower at 2 gallons per minute (40 gallons of HW)? The tankless units rated for that use (say to maintain 130F) are in the neighborhood of 16KW I think. So 20 minutes at 16 KW is roughly equivalent to one hour at 5KW. I'll have another 40 gallons in one hour.

 

I'm not sure the above is correct, but it seems you have to do a lot of math to figure out if you really save with a tankless. It seems savings are use/user dependent. If I put a timer on my conventional WH to run 1hour in the morning for showers and 1 hour before dinner for the dishwasher, I 'm only doing 9 kw a day assuming it needs the entire hour to heat the tank up.

 

Thanks again for all the info. Very informative.

 

RSTDdog

Link to comment
Share on other sites

I'm surprised that it hasn't been mentioned yet -

 

when I can't afford to take a hot shower, my next option would be to do as so many have already done. sell everything, spend the money on non-recoverable extravagancies such as vacations and then simply go on welfare. case closed

Link to comment
Share on other sites

Having lived in my Florida home now for 21 years I have had to change the water heater at least 4 times (7 if you count the failed experiment models) due to the extreme hard water situation here. After the first one failed I tried some of the fancy "no leak" "longer lasting" "energy saver" models and they all failed within 6 months. Glad Home Depot was willing to take them all back. I went back to the standard 40 gallon 6 year warranty Rheem and all is well. The last one actually started leaking after 4 years so it was replaced free under warranty. And I also buy them from a plumbing supply store, not the big box stores, which have them spec'd to their standards. Also installed brass nipples..ok, get it out of your system now....Which dont clog up the way the standard steel nipples do.

Edited by Ruffy
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...