Tankless hot water heater

[hosedragger622]

The time has come to replace my hot water heater, thinking of the tankless heaters, anybody got the pros and cons?

 

[Streetbu]

I have had mine for 5 years. Love it! They work better on public water, I use mine on a well though. Make sure to install a pressure regulator AFTER your pressure tank though. Varying water pressure changes the water temp.

 

[kd3pc]

electric = not so good
natural gas = good

not sure why Street says they work better on public water? As long as you have similar water pressure they should flow the same. Perhaps it is the accumulation of sediment or scale that will require the tankless to be cleaned 3 or 4 times a year?

Many times installation and plumbing the tankless correctly will negate any savings you anticipate.

 

[stikman56]

The time has come to replace my hot water heater, thinking of the tankless heaters, anybody got the pros and cons?

Why would you want to heat hot water?

 

[2mJps]

I would like to know if they realy save money in the long run becaues they are so high to buy in the first place. Every thing i have read and heared is they wouldnt save money if there are alot of people useing one like a large family.

 

[Scott H in Wheaton]

Why would you want to heat hot water?

I was thinking the same thing.
I have a cold water heater.
Water goes in cold, comes out hot.
Maybe with the tankless ones you have to start with hot water.

 

[mackwrench]

Mines LP gas fired.....love it! Has a wall mounted thermostat inside, I keep set at 110, take a shower w/o turning any cold water to mix it to temp.....

With a tank heater I was paying to heat water only to mix it with cold so I could use it?

Dishwasher has a add heat function so I keep it set there....my dishwasher only runs every other week.....

But I don't know about the electric model...NG or LP is the way to go.....most cities / electric companies have a pretty strong rebate program on them....

 

[CNGsaves]

+1 for NG or propane. Make SURE you have capacity (ie meter, pipe size from meter to mechanical room, etc) to handle the Btu that tankless heater will require (it's a LOT).

Tankless will be more expensive (obviously) than normal 40 gal NG heater, but WITH PROPER SIZING the limitless flow of hot water is rewarding. Work with a plumber who has experience with tankless.

There are new freeze-proof dual spigots for outdoors, so you could have hot and cold faucet to wash vehicles, pets, etc outdoors year-round.

Mounting location is critical to lower install expense also as horizontal exhaust/inlet to outside is easiest if you actually hang tankless on exterior wall. Thus, generally cheaper to run water and NG lines farther.

Consider also adding whole house filter / softener while you're tearing into all the water lines. Route incoming cold water directly to outdoor faucets, unless you want to pay for filtering/softening your garden water.

 

[David W]

I heard that the EPA is mandating more efficiency out of regular water heaters so whatever nit-wittery comes out of that may make a tankless water heater the better buy.

I know that the nickel I save every month in my high efficiency furnace and clothes washer won't come close to paying for a service call when one of those extra bells and whistles takes a dump.

 

[Streetbu]

Mine is LP, On a well as the water pressure varies, the flame size varies too. Higher water pressure equals larger flame. But it's not proportionate at least on my Bosch unit it isn't. Hence the temp varies up and down and why I said to put a pressure regulator after your holding tank if you're not on public water. Maybe other brands are better, just telling you about mine. Still wouldn't trade it. Nice being the 3rd person to take a shower in the morning and still having hot water!

 

[Strouty]

Mine is just a water heater, it doesn't care what temperature it starts at, it just wants to heat it.

 

[Voi]

We have a NG Rinnai. Put it in the last year the non-condensing types were made which was also a year tax write offs were available for installing tankless heaters.

Our gas bill has gone down quite a bit but we made so many changes to our home at the same time and I'm skeptical the water heater made a huge difference.

Our home is well suited for a tankless heater since our three bathrooms all share a wall and/or floor. There are very short runs from the heater to our three bathrooms. Our longest run is to the kitchen sink and even that isn't very far.

My sister remodeled her home around the same time and was advised to go with a traditional tank heater since he home is much more spread out.

We're very happy with it and if we every buy another house I'd seriously consider switching from a tank heater to tankless again.

 

[bpj71]

I just purchased a GE hybrid water heater which uses heat pump technology to heat the water. As long as the temp is above 45 degrees it pulls heat from the air and converts into a source for the hot water. It's supposed to be 675 watts vs 4500 to 5500 watts of a normal water heater. It also acts as dehumidifier for my basement/garage. I don't know the financial savings yet as it was installed the same time as the heating season hit.

It delivers 65 gallons in the first hour and I am very happy with it so far.

 

[SimS]

BPJ;

I hope you bought an extended warranty for your GeoSpring. I have one and it has failed three times in 2 years. They have a bad reputation in general. I wish I did better research before buying. Things to look out for: Condenstate pan cracks. You have to remove the heat pump to replace the extra flimsy plastic piece. Computer failure. My has failed again and it is now in "default" mode. i.e. regular water heater no heat pump. They save money when they run correctly. I hope you got a good one. Maybe mine is a lemon. There are many horror stories on the net. I'm going to replace it when my finances recover.

SimS

 

[G McKay]

The only thing I have against the tankless water heater is the price. The last time I looked a 40 gallon electric water heater was about $400.00 at Sears. The tankless heaters are around $1500.00.

I would definitely go with electric either way. I wouldn't waste my time with one that used gas. Too many disadvantages with them.

 

[yeldogt]

The newest modulating units are supposed to be better, guess if you are running propane and use a lot of water it may be worth it ... but with natural gas .. no way I would want one for the whole house.

The electric ones use a lot of power and often the service needs upgrading -- mine did at the beach for an addition.

They are fine for an "add on" bathroom or out in the shop -- but I have never been in a house with multi bathrooms and any size where they worked out well.

In the off months when I only run the dryer/ water heater / stove ... I spend about 35-40 bucks .. I just don't see how they save with NG.

 

[kd3pc]

I would definitely go with electric either way. I wouldn't waste my time with one that used gas. Too many disadvantages with them.

Electric ones usually require rewiring, as they can draw 60 Amps or more....and many times replumbing to get the needed heat delta from inflow to out flow.

I can't think of a single disadvantage to nat gas operation, cheaper for NG than electric when used, by far.

 

[Pluribus]

I have an older propane fired Bosch. It works for me, but I'm ok with the limitations.

It will heat up the incoming water a set amount at a given pressure. If my well pump kicks on, then the higher pressure coming in, and what I assume is a higher flow rate, causes the temperature to drop at the showerhead. With the pump on, I am also probably getting water right out of the ground instead of from the pressure tank. The water temperature may be different between the two, so it will again change the temperature at the showerhead. I may be screwing up some of the flow and pressure terminology, but hopefully this makes sense.

Tankless also isn't so great when you'll be turning hot water faucets on and off, say while doing dishes or in a clothes washer that cycles incoming water. There's a pretty big lag, and it often creates the "cold water sandwich" when the cold flows through the lines until the water heats up again. You can actually end up wasting quite a bit of water or never getting the warm water you want in the clothes washer.

Overall, they have good points and bad points. Not sure what I'll do when mine dies, but I may end up with a tank style next time.

 

[DonPowers]

Was considering replacing my 20+ year old tank with a tankless.

I get my water from a well and the local dealer said I would also need to install a softener to prevent the heat exchanger from fouling.

A friend who has an electric tankless put a small regular hot water heater downstream of the tankless, to eliminate/minimize temperature fluctuations.

 

[mygarageone]

Ondemand water htrs are great when they work properly and the Takagi is one of the best out there. Finding some one who will service it will be your biggest problem.
I have installed several of these units and haven't had any problems , even from the first one installed 7 yrs ago , it is on city water.

 

[Garage5.9]

Why heat the water if it's hot already

 

[davidlee]

I have two tankless units and I love them. One is for the upstairs and will handle the three bathrooms the other is for downstairs for the other two baths , laundry and kitchen. They are NG.
As for as money savings I doubt it because we now take longer showers since we don't worry about running out of hot water.

 

[Banjorear]

We bought a house that had/has a Rinnai NG fired unit. Previous owner installed it prior to moving in. We hate it. The unit is really sensitive to flow volume. The house was buit on the 60's so I'm not sure if the pipe arent sized correctly but many times you need to turn the water on then off and then on again to trick the sensor to think it is flowing enough. We've had two guys come look at it and they say it is working fine and it is a plumbing issue.

In my previous house, I installed a Triangle Tube indirect hot water tank and loved that set up. It held hot water for days. It was so efficient, it only lost 0.5 degres an hour.

 

[andys]

+1 for the GeoSpring hybrid unit. My old heater leaked in October 2013 and I looked at new ones in the home stores. I would have been at $5-600 for a standard heater, the GE was $1100 or so. There was a utility company rebate of $400 right off the top so it was almost a wash at that point.

My heater is on its own off-peak meter which is no longer off-peak but is still listed separately on the bill. I use about 1/6 the amount of kWh as I did with the old one. At this point I am at least even or slightly ahead. I would have gotten more rebates from the Feds but I had already reached the limit for energy efficient improvements.

 

[Charles (in GA)]

A friend of mine sold the old family farm. Couldn't justify keeping it any longer. She moved about 3 miles or so to a house in town, it was her grandmother's and I don't know how long it was in the family before that, it is a Civil War era house. She couldn't find anyone who would do the replumbing so I have been working on it. Almost done. She bought a Noritz LP 90% condensing instant water heater, 157K btu. She thought it had to be installed by a authorized rep to get warranty on it (turns out the warranty doesn't say that at all) and she jumped the gun and had this guy show up the same day the LP gas people were running new black iron pipe and setting her old tank from the farm. The "authorized rep" showed up in a Caravan with a handful of tools, looked like an over age biker dude with a beer gut, ponytail, and a leather vest with a bunch of various patches sewn on it. (mind you, no offense to anyone who resembles that, but for a businessman who does work like this, its NOT a good image). He proceeds to tell us how he has been installing Noritz for 20 years and is so good at it, etc, and then opens the box, takes one look and exclaims "never seen one like this before". After that we simply told him we would call him when we were ready with the plumbing (he ain't about to get called again). I thoroughly read the installation manual over and over, checking every requirement and clearance to insure it is installed to the "manufacturers requirements" (a condition of the warranty). It is a through and complete installation manual, and we are waiting for the gas people to come back and do their hook up. I have run water thru it and leak tested it and all of the fittings and couplings supplying it.

My friend had an older model out at the farm for a number of years. She understands how they work and the limitations of them, and is quite happy with it.

 

[mackwrench]

We bought a house that had/has a Rinnai NG fired unit. Previous owner installed it prior to moving in. We hate it. The unit is really sensitive to flow volume. The house was buit on the 60's so I'm not sure if the pipe arent sized correctly but many times you need to turn the water on then off and then on again to trick the sensor to think it is flowing enough. We've had two guys come look at it and they say it is working fine and it is a plumbing issue.

In my previous house, I installed a Triangle Tube indirect hot water tank and loved that set up. It held hot water for days. It was so efficient, it only lost 0.5 degres an hour.

What water temp is it set at?.....have you tried to lower temp setting? These units have a flow valve that senses water temp, once water get overheated, it's cut off/back......

If your flow is too low, it will shut down. More often with higher then needed water temp.....

 

[G McKay]

Electric ones usually require rewiring, as they can draw 60 Amps or more....and many times replumbing to get the needed heat delta from inflow to out flow.

I can't think of a single disadvantage to nat gas operation, cheaper for NG than electric when used, by far.

I replaced my water heater years ago and I didn't have to do any rewiring. I just put it in.

And the main disadvantage of any gas appliance? How about an EXPLOSION just for starters?

 

[flyng_fool]

I replaced my water heater years ago and I didn't have to do any rewiring. I just put it in.

And the main disadvantage of any gas appliance? How about an EXPLOSION just for starters?

Oh please. If it wasn't safe they wouldn't have NG appliances.

 

[Charles (in GA)]

I replaced my water heater years ago and I didn't have to do any rewiring. I just put it in.

I assume you are referring to replacing a tank type with another tank type, or a instant electric with a like instant electric.

The poster you are commenting to is referring to replacing a tank type, which typically has 3500 to 4500 watt elements and is wired on 10 gauge and 30 amp double pole breaker, with a instant electric unit where at least one 60 amp double pole breaker (and #6 wire) or units above 18K watts that require TWO double pole breakers, TWO separate circuits/wire runs, and breakers of 40 to 60 amps.

Its quite possible on an instant electric unit that will supply a house, to draw a hundred amps from the panel when it is working to capacity.

ANYTIME you replace a water heater you need to do calculations to determine that the existing circuit is still capable of supplying your new unit.

Charles

 

[olytdi]

I installed a Bosch Aquastar about 13 years ago and it's never missed a beat. Reduced my NG bill by half and has paid for itself over and over. About every 7 years or so, I install a rebuild kit for the valve.

One of the best upgrades I've ever done. Really nice to have unlimited hot water...especially in a power outage!

 

[Glacial_Speed]

The time has come to replace my hot water heater, thinking of the tankless heaters, anybody got the pros and cons?

The house we purchased came with a tankless heater. Part of the oil fired boiler.

You don't mention where you are, but I definitely notice the tankless when the outside temp takes a dive and the incoming water is about 38 degrees.

I have a few problems with my tankless heater, the first is it wasn't sized correctly. I can (barely) take a shower in winter at 2.5 gpm (gallons per minute) but filling a bath at 6 gpm will result in a cold bath. The second is the installation, the faucet is about 30 feet of pipe away from the heater, so there's a good amount of water wasted waiting for hot. The third is the DHW mixing/anti scald valve is also located on the boiler and far away from the faucet so it loses a bunch of heat before it arrives.

Overall I would say my problems with a tankless stem from wrong sizing and a poor install. This isn't to say a tankless isn't good, just that the install is more sensitive to error.

I'm looking at the cost of an indirect tank and zone controls.

 

[willymakeit]

I replaced my water heater years ago and I didn't have to do any rewiring. I just put it in.

And the main disadvantage of any gas appliance? How about an EXPLOSION just for starters?

Plus for NG is when the power was out I still had hot water during the last ice storm. Changed my cooking stove back to gas and used the extra breakers for the garage.

 

[CNGsaves]

I just purchased a GE hybrid water heater which uses heat pump technology to heat the water. As long as the temp is above 45 degrees it pulls heat from the air and converts into a source for the hot water. It's supposed to be 675 watts vs 4500 to 5500 watts of a normal water heater. It also acts as dehumidifier for my basement/garage. I don't know the financial savings yet as it was installed the same time as the heating season hit.

It delivers 65 gallons in the first hour and I am very happy with it so far.

How much for unit . . AND . . how much to install?? Also how many gallons iin holding tank?? What all power/NG requirements (ie electrical amps / NG black pipe size)?? Model # ??

What climate / temperature is it operating . . . . generally say a 50 degree basement with 60 percent humidity . . . . or what??

 

[Banjorear]

What water temp is it set at?.....have you tried to lower temp setting? These units have a flow valve that senses water temp, once water get overheated, it's cut off/back......

If your flow is too low, it will shut down. More often with higher then needed water temp.....

135. Is that right or too high?

 

[G McKay]

Oh please. If it wasn't safe they wouldn't have NG appliances.

That's like saying: If people had gasoline fires, they wouldn't have gasoline powered cars. Or they wouldn't have fires at the gas pumps that set entire gas stations on fire. Really?

 

[G McKay]

I was referring to replacing a tank type water heater with a tank type water heater. If you are referring to replacing a tank type water heater with a tankless water heater then yes, it would take more amperage. I agree with that. But, so what? It is still cheaper in the long run. But it is more costly to install.


In colder climates, it is a lot more expensive to have a gas/fuel oil/propane type home than a straight electric type home now days. Less dangerous, too.

 

[mackwrench]

135. Is that right or too high?

On mine 135 was max temp....Try trun it down to 120....or if you can stand it, 115..... If in fact your pipes are smaller and limiting flow it will help.....

I'll bet yor not showering with 135 degree water....your mixing cold with it....

Try to get into habit to only turn hot water on w/o cold by using thermostat...I tale it you have an inside thermostat?

 

[Banjorear]

On mine 135 was max temp....Try trun it down to 120....or if you can stand it, 115..... If in fact your pipes are smaller and limiting flow it will help.....

I'll bet yor not showering with 135 degree water....your mixing cold with it....

Try to get into habit to only turn hot water on w/o cold by using thermostat...I tale it you have an inside thermostat?

Correct. 135 is max. I'll try lower it and report back. When you say inside theromstat, what do you mean?

 

[mackwrench]

Correct. 135 is max. I'll try lower it and report back. When you say inside theromstat, what do you mean?

Mine has a wall mounted digital thermostat inside the house that I can use to change the temp at random.....in winter I keep it @ 120, summer 115

....The usage manual that came with mine stated it uses 30% more fuel from 115 to 135....plus I the extra cost of cold water needed to get the temp down enough to use....

...there's also some dip switches outside in the unit that enable the unit to go to 140....if you don't have the manual, you can download it from mfg site

 

[mackwrench]

In colder climates, it is a lot more expensive to have a gas/fuel oil/propane type home than a straight electric type home now days. Less dangerous, too.

Not sure I get that logic........perhaps you can explain? And whats so less dangerous?