New Hot Water Heater - Help Needed

[Carpenter]

Hi All,

I'm looking for the "experts" to come out and tell me what I need to do here. I started looking last night into a new Hot Water heater since we can no longer take a shower, and run the dishwasher (on quick cycle) anymore without running out of hot water.

I knew this day was coming since the current one came with the house (10 years ago). I read that is average time for a heater.

We currently have a tank gas heater with I believe electric ignitor. I am totally confused. Should I get another tank heater and just stay status quo, or should I venture into the whole-house tankless variety?

We currently have 2 baths and the dishwasher and clothing washer (front load).

I understand that with tankless, you won't have hot water immediately, which is Ok, since we don't step into the shower as soon as we turn the water on. However, I'm one of the guys that go with proven things. Is a whole-house tankless solution proven, or am I going to regret going with one?

What else am I forgetting to tell you to help me make a decision?

I really hate making a decision when I can't even figure out the right questions..

 

[Mike Painter]

Try tankless for mostly less than positive reviews.

I went with a new conventional heater when I replaced mine. During the summer about 95% or more of my gas bill is from heating water.
I'm single and the difference between a tankless system and what I bought would have taken many, many years to make up the difference even had I put the new one in an unheated, uninsulated garage and ran the pipes underground which is where the old one was.

 

[BB]

Have you tried draining the hot water heater (hook a hose onto the bottom and run it outside)?

Generally, that (and a failing/miss-set thermostat) and a clogged burner jet are the only things that would cause a hot water heater to "lose" capacity...

Oh, and a failed "dip tube" (on the cold water inlet, there is usually an aluminum or plastic tube that injects cold water into the bottom of the water heater--if the tube breaks or is melted off by somebody sweating a copper fitting while mounted to the take--it will mix cold and hot water at the top of the tank).

If your water heater is over ten years hold--you may have more work trying to replace the dip tube (rusted/broken cold water fitting while trying to get to the dip tube)--you may be correct in replacing the whole water heater if you get too much time into the repair.

I do believe in "conservation"--and tankless water heaters have their place. However, they are expensive to buy and possibly to install (may need larger natural gas line to heater, new stainless steel vent stack) and such.

The "low end units" do not do a good job of temperature control (have to leave the shower on high to get minimum gpm flow of 0.6 gpm or higher, and if you vary the volume--you have to play with the cold water to get the temperature back right).

I am sure the newer/more expensive tankless heaters do a better job--however, the minimum flow rate is usually higher that I set my home shower too (we are in California--the land of just coming out of water rationing, in water rationing, or just entering water rationing--all the while water pricing keeps going up with each transition).

Also, some tankless units are not quiet... I probably would make the retailer/installer show me a working installation with same model before I laid out the money given that you will be spending 2-4x the price over just a do-it-yourself tanked heater replacement to save $10 per month (for me, that is a ~50% reduction in my hot water bill during the summer months--no central heat costs).

-Bill

 

[IlluminatingBikr]

I have a tankless water heater at my house and it's great. It's not very noisy (it's in the garage anyhow) and there's an endless supply of hot water. When we go on trips there isn't a bunch of wasted hot water. Also, we have a control unit in the main bathroom which you can set the temperature on, as well as read out the incoming water temperature, outgoing water temperature, and flow rate.

We usually leave it set at 120 or so, but if we do a load of rags or something then we can crank it up to 140 or even higher, and get that temperature instantly.

 

[BB]

Try tankless for mostly less than positive reviews.

I just started reading through a few of the posts... For the most part, I agree with their criticisms of tankless water heaters.

Tankless water heater save money for people that rarely use hot water (no hot tank sitting idle wasting energy). The efficiency to heat the hot water seems to be about the same between the average tanked vs tankless unit (I ran into this very interesting factoid while doing research on my next hot water heater change out--mine is 12+ years old, and I am waiting for the next failure--the old 50 gal tanked heater from home depot is still working great for me now).

So, in some ways, unless you get a very high end condensing water heater, the more hot water you use, the less the savings (if that makes sense).

Thank you,
-Bill

PS: Plus, for any trips, just turn of the water heater--the new "sealed" burner types they are selling in California (to help prevent gasoline fume explosions) include a Pizo Electric igniter -- very easy to re-light.

Also--if you have power failures, most all of this require AC power to run--really nice to have hot water when the power is out....

 

[LukeA]

If you can't take a shower and run the dishwasher at the same time then a tankless water heater is not for you. There aren't any tankless models that have even the capacity that you have now. Or if you can find one, you will pay through the nose for it. You just need a larger capacity conventional heater.

If that doesn't solve your flow problem, you may consider uprgading to 3/4 in. supply lines to (at least) the shower.

 

[LuxLuthor]

I had this exact same problem on a 9 year old water heater, and was planning on buying a new one.

Fortunately I have a good friend who is a plumber, and he first mentioned the common issue that BB mentioned, namely that the cold water inflow pipe can break down, so all the cold water just layers up at the top, rather than being sent to the bottom and triggering a heating cycle. This is what he calls "designed obsolescence" as the water heater companies know it will trigger more sales. Most people do not know about this issue.

He spent at most about 10 mins replacing the broken down plastic tube with a copper pipe, and about 7-8 years later, it's still working perfectly. After watching him do it, I could easily do it myself.

 

[Valpo Hawkeye]

LuxLuthor is right that a broken dip tube can result in poor performance. However, after a class-action lawsuit several years ago, these have been improved. That's not to say yours is definitely okay, something worth checking out.

Another consideration is a heavy layer of sediment on the bottom of the tank. This insulates the water from the burner causing more heat to go up the flue and less transferred to the water in the tank. Oftentimes, draining the water heater isn't enough. It's best to purge it under pressure. If you do this, make sure you realize very hot water will be coming out. If this concerns you, turn the thermostat all the way to "vacation" or "pilot" and run the tub for 10 minutes to temper the water.

Once you do this, hook a hose up to the drain valve and put the other end in a 5-gallon bucket. With the water still on, open the drain valve and see how much sediment you can get out of the tank. Continue to do this until you no longer get sediment.

As far as tankless goes, on average they only save approximately 20% in utilities and have a higher initial cost than a storage-type water heater. They also have a heat exchanger than requires regular maintenance and they have complicated controls similar to a high-efficiency furnace. This also contributes to a higher maintenance cost. Their only plus side is unlimited hot water, but the trade-off, in addition to what is listed above, is a limited flow rate.

Finally, FWIW, I'm a licensed plumber.

 

[TedTheLed]

another way to clean out the minerals layering the bottom of a storage type tank in hard water conditions is to patch (tape) a garden hose (or same diameter tubing) to a wet vac, remove the heating element (four screws and it's out) and vacuum out the deposits through that hole..
I've had a Tagaki tankless for over three years and it has required no maintenance. If minerals formed in the exchanger the flow would diminish, which it hasn't -- I think the minerals form after they are heated, not in the exchanger, but in the pipes after the exchanger, which results in clogged shower heads and/or shower valves.
I fixed the valve problem by drilling out the valve and the tiny spaces the minerals got clogged in (the temp-balancing mechanism) and remove the shower head and shake out the granules every few showers..drilling the temp-balancer thingy didn't affect the temperature of the shower... then again no one has flushed or done laundry while I was showering..
I had another tankless before this one for 5 years and it never developed a flow problem either..it still works too..

 

[LuxLuthor]

LuxLuthor is right that a broken dip tube can result in poor performance. However, after a class-action lawsuit several years ago, these have been improved. That's not to say yours is definitely okay, something worth checking out.

Another consideration is a heavy layer of sediment on the bottom of the tank. This insulates the water from the burner causing more heat to go up the flue and less transferred to the water in the tank. Oftentimes, draining the water heater isn't enough. It's best to purge it under pressure. If you do this, make sure you realize very hot water will be coming out. If this concerns you, turn the thermostat all the way to "vacation" or "pilot" and run the tub for 10 minutes to temper the water.

Once you do this, hook a hose up to the drain valve and put the other end in a 5-gallon bucket. With the water still on, open the drain valve and see how much sediment you can get out of the tank. Continue to do this until you no longer get sediment.

As far as tankless goes, on average they only save approximately 20% in utilities and have a higher initial cost than a storage-type water heater. They also have a heat exchanger than requires regular maintenance and they have complicated controls similar to a high-efficiency furnace. This also contributes to a higher maintenance cost. Their only plus side is unlimited hot water, but the trade-off, in addition to what is listed above, is a limited flow rate.

Finally, FWIW, I'm a licensed plumber.

I did this just for the heck of it, even though the intake tube had been replaced a number of years ago, and I was amazed how much crap was in the bottom that flushed out. Thanks again for this tip.

 

[TedTheLed]

in this hard water area the heating element at the tank bottom would become completely buried in 'rocks and pebbles' ..

 

[Carpenter]

LuxLuthor is right that a broken dip tube can result in poor performance. However, after a class-action lawsuit several years ago, these have been improved. That's not to say yours is definitely okay, something worth checking out.

Another consideration is a heavy layer of sediment on the bottom of the tank. This insulates the water from the burner causing more heat to go up the flue and less transferred to the water in the tank. Oftentimes, draining the water heater isn't enough. It's best to purge it under pressure. If you do this, make sure you realize very hot water will be coming out. If this concerns you, turn the thermostat all the way to "vacation" or "pilot" and run the tub for 10 minutes to temper the water.

Once you do this, hook a hose up to the drain valve and put the other end in a 5-gallon bucket. With the water still on, open the drain valve and see how much sediment you can get out of the tank. Continue to do this until you no longer get sediment.

As far as tankless goes, on average they only save approximately 20% in utilities and have a higher initial cost than a storage-type water heater. They also have a heat exchanger than requires regular maintenance and they have complicated controls similar to a high-efficiency furnace. This also contributes to a higher maintenance cost. Their only plus side is unlimited hot water, but the trade-off, in addition to what is listed above, is a limited flow rate.

Finally, FWIW, I'm a licensed plumber.

Well, the water heater didn't act up again since the original post. However I am going to try this and see what happens :devil:
Funny thing is I did assist in replacing a heater just 2 weeks ago when my parents died on a Sunday. Luckily the next door neightbor knew enough to plumb everything back together since the old hookups were 20+ years old. I got quite a lesson that day.

Also, if/when I do replace it, a regular tank system will be going back in.

 

[andrew123]

Wait just a minute. You are going to get something that will heat your already hot water. You are going to get your hot water heated again? what was wrong with the hot water to begin with?

 

[chmsam]

No.

On demand or tankless systems are small water heaters that use a lot of energy to keep up with the need for hot water only when it's being used. Standard hot water tanks hold a larger volume of water at a preset temperature -- that's better if you regularly use a fair amount of hot water.

The standard hot water tanks have a cold water feed that puts fresh, cold water in at the bottom of the tank since hot water rises. If that tube breaks down cold water gets fed in at the top of the tank where the hot water would be run off into the hot water pipes.

Sediment collects at the bottom of a standard hot water tank and you should drain off the water tank to flush that out on a regular basis. What was mentioned was to examine the water being drained off so you could see what it looks like.

No one was talking about pre-heating or re-heating water.

Having said that, years ago there were plans on the web for taking an old hot water tank and putting it into a home made solar warming box with only the water connections made -- no gas or electric hook up to that old tank (the old tank becomes a passive solar pre-heater with free energy). By running the pre-heated water from that into the regular hot water tank you can avoid heating a fresh, cold water supply that could be starting out as low as 40 degrees F, and heating it up to the normal 120-140 degree F. You save energy by having to heat the water from the solar pre-heater that is feeding into the standard hot water tank at temperature that's already at 80 degrees F or warmer. The savings comes in because it costs less to heat water only another 40-60 degrees than it does to heat it a total of 100 degrees, which is what a regular water heater does. The old water tank costs nothing and you only pay for plumbing, check valves, and the cost of constructing the solar heating box (cheap stuff).

 

[Random Guy]

No.

On demand or tankless systems are small water heaters that use a lot of energy to keep up with the need for hot water only when it's being used. Standard hot water tanks hold a larger volume of water at a preset temperature -- that's better if you regularly use a fair amount of hot water.

The standard hot water tanks have a cold water feed that puts fresh, cold water in at the bottom of the tank since hot water rises. If that tube breaks down cold water gets fed in at the top of the tank where the hot water would be run off into the hot water pipes.

Sediment collects at the bottom of a standard hot water tank and you should drain off the water tank to flush that out on a regular basis. What was mentioned was to examine the water being drained off so you could see what it looks like.

No one was talking about pre-heating or re-heating water.

Having said that, years ago there were plans on the web for taking an old hot water tank and putting it into a home made solar warming box with only the water connections made -- no gas or electric hook up to that old tank (the old tank becomes a passive solar pre-heater with free energy). By running the pre-heated water from that into the regular hot water tank you can avoid heating a fresh, cold water supply that could be starting out as low as 40 degrees F, and heating it up to the normal 120-140 degree F. You save energy by having to heat the water from the solar pre-heater that is feeding into the standard hot water tank at temperature that's already at 80 degrees F or warmer. The savings comes in because it costs less to heat water only another 40-60 degrees than it does to heat it a total of 100 degrees, which is what a regular water heater does. The old water tank costs nothing and you only pay for plumbing, check valves, and the cost of constructing the solar heating box (cheap stuff).

I think what andrew123 meant was that the proper term would be cold water heater, since water heaters take cold water and make it hot. Hot water heater would imply that the water heater took hot water and heated it again.

 

[sunspot]

Here is a cool site about water heaters.
http://www.waterheaterrescue.com/