Hot Water On Demand?

[Off in the Bushes]

If I was going to get a tankless hot water heater I would install a water softner, so the fine heat exchanger does not foul up with calcium. That is where it becomes so efficient, the energy (heat) from gas is transfers to water quiet easly if the volume of water it is heating is small, hence the fine finned heat exchanger. As for getting it hot they just control the flow of cold feed water to the heater, thusly less water going be with the same amount of gas equals warmer water.
If you look as your old hot water tank and see the amount of calcium that percipiates out (comes out of the water) that is going to be in your tankless hot water heaters heat exchanger years down the road unless you have a zero hardness softner. That scale will imped the heat transfer from the gas to the water, eventually making the hot water heater useless.
Thats just my opinion

[beerhunter]

We have a Rinnai, don't know which model, approx 3 yrs old. When we first moved into the house the water wouldn't get as hot as I like so my dad did a little research and found there was a adjustment inside the box and now the temp gets to where I like it and its great for filling up the jet tub and not worrying about running out of hot when company is over and everyone having showers. Depending on which tap you are using, closest to heater or farthest from heater, it does take a little while for the water to get hot.
Does anyone know what you need to fix this issue? I find that I may use more water than I might with a hot water tank sometimes.
Comparing my bills with the previous hot water tank vs tankless heater the only thing I think I have saved is the space where the hot water tank would have been. I bought the house with the tankless system and I do like it very much.

[beerhunter]

Oh I forgot one other thing someone mentioned earlier about regular maintenance for these kinds of heaters. Please enlighten us please because I would like to make sure my Rinnai lasts a long time.

Thanks in advance.

[roots]

Just an idea, if you are going with the tankless and your current hot water tank doesn't leak then turn off the gas to it and use it as a storage tank for the water entering the building. This will allow the water to warm up a bit before it enters the tankless heater.

[mark-edmonton]

Originally Posted by Springer

My house is 4 years old and i run a Takagi. It has already been replaced once due to it misfiring like a worn out Model T. So it gets replaced,...a year later we are having issues, it takes 5 minutes to get hot water and finally you jump in & if your lucky it stays hot but most often it turns Cold for awhile then finally hot. I preferred my other system with the 2 hot water tanks.
Oh yes and my upstairs floor heat does not meet temp anymore. The system has been flushed with vinegar and no improvement. Personally i think the takagi is Junk and very expensive.

Agree. I installed a bank of % commercial takagi's a few years back for a hotel. they were a set-up and maintenance nightmare

[shebadog57]

Dodger

I have a Navien tankless on demand water heater in my home, when they work, they work excellent but the problem i have had is when in our climate it gets stupid cold out, the units which draw unheated air in to the unit in side a warm house,there is a condensation. On these units there are alot of flow sensors which if they dont meet a level of flow they default to off. Now having said this, my installers have serviced without problem and have warranteed without problem, so service is awesome.
Would I reccommend? Yes I would, but if you get one, have the installer walk you through the owner maintence.
Im in the Military and spend time away from home quite often so I require something low maintence/ high service. This was a good buy but high cost.
Pm if you need and other info...
Cheers
SB57

[Springer]

So do you plumber fellas think its the takagi or is there a check valve passing ?? Actually i bought my home from the Plumber that built my house here in Red Deer. I dont want to bash his company name but when he came to replace it he was scratching his head trying to fix it and spent 5 hrs doing it,there are also other drain leaks ,shower extra spray head would not shut off etc. My wife wont let me call him back. Who can help us out in Red Deer??
I had galaxy flush my tank to lean the calcium up..Oh and the expansion tank on it had a blown bladder.

[jpohlic]

Originally Posted by roots

Just an idea, if you are going with the tankless and your current hot water tank doesn't leak then turn off the gas to it and use it as a storage tank for the water entering the building. This will allow the water to warm up a bit before it enters the tankless heater.

A better idea is to use a wastewater heat recovery system on your shower drain. It preheats the incoming water by using the hot water going down the drain.

They are easy to install and quite efficient.

[gdbccb]

Originally Posted by shebadog57

Dodger

I have a Navien tankless on demand water heater in my home, when they work, they work excellent but the problem i have had is when in our climate it gets stupid cold out, the units which draw unheated air in to the unit in side a warm house,there is a condensation. On these units there are alot of flow sensors which if they dont meet a level of flow they default to off. Now having said this, my installers have serviced without problem and have warranteed without problem, so service is awesome.
Would I reccommend? Yes I would, but if you get one, have the installer walk you through the owner maintence.
Im in the Military and spend time away from home quite often so I require something low maintence/ high service. This was a good buy but high cost.
Pm if you need and other info...
Cheers
SB57

We too have a Navian and, while I am very happy with it, we have experienced similar "flow sensor" shut down issues. In our case, what was happening is that the small grate that covers the input air pipe openining outside the house would get covered with popular fuzz/dandelion fuzz/whatever and the reduced input air would shut the unit down. It was amazing the small amount of fuzz that would trip the flow sensor. Our contractor finally reconfigured our system so that input air comes from inside the house, not outside and we haven't had problems since.

In terms of cold input water, we considered getting a solar panel set up to pre-heat the water going into the tankless for this reason, but we ultimately didn't and haven't had any issues with the GPM we're getting from our unit - more than enough to have the shower with two body jets and one or two bathroom sinks or dishwasher going at the same time.

[Vindalbakken]

Originally Posted by jpohlic

A better idea is to use a wastewater heat recovery system on your shower drain. It preheats the incoming water by using the hot water going down the drain.

They are easy to install and quite efficient.

The eco-energy? grant will give you money back to install one of these as well. I haven't put one in because the majority of the showering in our house is done in the basement bath. This unit does not help you to fill a large jacuzzi, to heat incoming water to the washing machine/dishwasher etc. It is only of use while using the shower that drains through the sewer pipe it is installed on. Still, a good idea I believe.

[dodger]

Thanks for the input everyone, it seems that most of you are happy with your tank-less systems. It looks like one brand may be worth staying away from. What is the maintenance required and how often?
Dodger.

[Justanotherbuck2]

After thirty years in the industry the use of demand water heaters is a great push for the federal gov to push green house gas reforms and global responsibility..both are achieved. the reality is the consumer over time saves little or zero. The math is simple. We sell several popular brands including the ones mentioned so far in this thread. take for example a retrofit 40 gallon natural gas water heater storage style..most common installed price of $975.00 plus gst.. our starting price for a demand system is $3400.00 so you start off $2425.00 more for the demand sytem before you have any savings.The AFUE rating for a storage tank is 82% the AFUE for a demand is 82%, true you are not warming water when not in use and you can have, if properly sized great long showers and do your laundry at the same time. With the average home with a storage tank using about 35-40 gigijules per year at an average cost over the last five years of $7.50 per gig, that works out to aprox. $300.00 per year, with a demand system you can take that down to about 20-25 gigs per year or $187.50 per year for a savings of $112.50. at the current prices that means a payback of aprox..23 years for your trouble barring any repairs or servicing. If you are buying a new home the demand system can be a asset and perhaps a small selling feature if you have unusual hot water requirements, home builders today are opting for less expensive electric storage heaters which meet the new building codes for energy efficientcy and of course require no chimney and the purchase price is nearly half that of a natural gas or propane waterheater of the same size. twenty years ago |I would never have reccomended an electric water heater but now that the costs of operation is similar it is a sensable choice due to the low installation and maintenance costs. For your information electric waterheaters and furnaces are 100% efficient as there is no flu product waste, transfer of energy is 100%. Well I could go on forever but it is late I have insomnia and wish to read a few more threads. Goodnight

[dodger]

WOW! Good info ! The one reason I was looking at the tank-less was for the unlimited hot water. The savings on energy cost was a non issue. I also thought it would be relatively maintenance free, I have now learned that this is not the case plus there is the additional soft water system that needs to be installed and maintained.

Thanks for the input from everyone, these are the type of comments you can "not" find when doing online searches. Nothing is better than input from people in your area and there experience.

Thanks to all !
Dodger.

[CaberTosser]

I wanted to make a note on that wastewater heat recovery piece that JPholic had posted. While its true that those would be prohibitively difficult to install underslab ( and I would doubt they are approved for that), with a bit of ingenuity they could be used to recover heat from bathtub wastewater. I have been considering this for myself. That unit is generally only installed as a preheat circuit in the feed water to your water heater or tankless system, water goes through it on its the way to the heater. It would be possible to incorporate a circulation pump with a preheat storage tank (ie: an electric water heater without any power run to it) and a thermostat to actuate the circ pump. This would allow water being drained from a bathtub (or any other fixture that has time delays between filling and draining) to preheat the water in the storage tank.

Despite being in the trade I have no personal experience with the tankless units just yet; so I have no input there, save for answering the question posed by Dodger about the maintenance on the units. These units as already noted have intentionally small internal waterways to allow for their rapid heat exchange. With hard water, mineral scale can build up in the units negatively affecting their performance. The units are normally installed with some service valves below them that have hose connections. These valves allow isolation from the building water and the hose hookups allow short hoses to and from a pail filled with vinegar or citric acid in solution. The acid is pumped into the unit with a hose discharging the acid back into the pail with the pump in it, recycling for a period of time to descale the heat exchanger. Obviously one uses a mild potable acid for this purpose, and flushes the unit afterwards before returning it to service or its "Honey....why does my coffee taste funny?"

[Justanotherbuck2]

as usual cabertosser has some great information, that recovery system caught my eye as well rather interesting looking device not sure what the cost is but it sure could eliminate the condensation problems of a demand system, I also think incorporating a recirc pump would be an asset. All of this should be about the reliability of the system not cost savings because I think the installation of these unless you are completing it for yourself will out price any savings. You can also put a filter on your inlet supply line to help protect your Demand system, remember this is a pretty high tech appliance and is not maintenance free. It is designed to take water from 55 degrees to 130 degrees Fahrenheit in three seconds, hence the reason for the extremely small piping,orifices, internal safeties and low flow water cutoffs, high temp cutoffs, ignition sensors etc the list goes on, also don't forget they are about 180,000 BTU's this sometimes means we have to run a new line right from your gas meter because since 1991 allot of homes have sized gas lines that are OK for the storage type tank and a furnace but do not have the capacity for adding large BTU equipment, if you are a large consumer of hot water Demand systems are great and have been around for more than 70 years in Japan and throughout Europe there are just alot of learning curves for Canadians to accept the cost associated with them.

[CaberTosser]

Originally Posted by Justanotherbuck2

as usual cabertosser has some great information, that recovery system caught my eye as well rather interesting looking device not sure what the cost is but it sure could eliminate the condensation problems of a demand system, I also think incorporating a recirc pump would be an asset. All of this should be about the reliability of the system not cost savings because I think the installation of these unless you are completing it for yourself will out price any savings.

First off I'd like to say thanks... its nice to get a compliment from a fellow industry professional . Your trade-related posts have good & well-presented information as well Justanotherbuck2. Sometimes I find guys in the industry who know what they're doing, but can't express it on paper worth a hoot. Then theres also some other guys.........

In mentioning my plan for that heat recovery system, it would be more something a person does because they can, not necessarily because they expect it to generate a quantifiable payback. In my case I would have to leave the system shut off for a year to get accurate gas useage feedback data, as its going into a new house where our annual natural gas GJ consumption will be an unknown.

I also want to note for those who might want to check it out, that there is an article in this months Fine Homebuilding magazine that just hit the newsstands on tankless water heaters, complete with photos illustrating an installation. I always enjoy that particular magazine; usually there lots of good information in it. Admittedly on occasion I may take exception to one or two things they say, but its certainly an exception rather than a rule.

[Slick66]

I have a Rinnai and its been great. It is a commercial unit so it provides domestic hot water and for the in-floor heat.
We are rural, and run well water through it with no problems.
Would definitely recommend a tankless.

[ELKOHOLICS]

The hot water waste recovery system is not that good there is no water pressure in the pipe, so water cannot transfer heat well plus the install price.this system was designed by some half-witt engineer.i do some solar installs(electrician).i came up with a simple idea if your intake of water is too cold just get a roll of pipe (pex) and add a coiled full roll to your existing intake cold
water pipe usually located in the nice warm mechanical room,the coiled full section will not take up that much room the water that is maintained in this pipe will be at room temperature instead of cold ,ultimately a holding tank or a roof mounted piping system would be ideal best of luck

[CaberTosser]

Originally Posted by ELKOHOLICS

The hot water waste recovery system is not that good there is no water pressure in the pipe, so water cannot transfer heat well plus the install price.this system was designed by some half-witt engineer.i do some solar installs(electrician).i came up with a simple idea if your intake of water is too cold just get a roll of pipe (pex) and add a coiled full roll to your existing intake cold
water pipe usually located in the nice warm mechanical room,the coiled full section will not take up that much room the water that is maintained in this pipe will be at room temperature instead of cold ,ultimately a holding tank or a roof mounted piping system would be ideal best of luck

I disagree.... strongly, for a few reasons. Firstly, Pex is a poor thermal conductor, it is used in slab heating systems yes, but if it were a good thermal conductor; there would be no heat left in the water at the end of a loop, and loops would then have to be shortened to accommodate. Secondly, a full roll of Pex, be it a 500 or 1000 foot roll, will reduce your water pressure. Thirdly; and this is a big one; if you keep the roll tightly bundled to minimize the space it occupies, then most of its surface area will not be available to the rooms air for heat transfer, it will be mostly contacting the rest of the roll. So your "compact" theorey is not true, at least not if you want it to function reasonably. Open that roll up and it may perform somewhat, but your compact theorey is out the window. Then at this point, your warm mechanical room (not always the case when people have open combustion air intakes spilling cold outside air into the room to feed the appliances) serves as the preheat for your water heater. How does that fare if your furnace is of lower efficiency to your water heater? It means you are losing efficiency, as well as increasing the BTU loading on your furnace.

Wayyyyyyy too Ghetto.

[Vindalbakken]

Some more sound advice from CaberTosser.

[deeker]

Who would be a good company to install a water softer in a house in Red Deer

[MK2750]

Bruins

[sansui]

http://www.aquatell.ca/water-softene...ater-softeners
Do it yourself, not that hard.

[ali#1]

I looked at it a few year ago too but the cost was rediculous and the benefit wasn't worth it, if I were to build new I might go that way though.

[Clgy_Dave2.0]

Originally Posted by ali#1

I looked at it a few year ago too but the cost was rediculous and the benefit wasn't worth it, if I were to build new I might go that way though.

lol....just read the OP and a few follow up posts huh?

The OP is almost 4 years old. It was bumped by the current discussion which is just looking for a water softener installer.

[ali#1]

Originally Posted by Calgary Dave

lol....just read the OP and a few follow up posts huh?

The OP is almost 4 years old. It was bumped by the current discussion which is just looking for a water softener installer.

I seen that.