I was told by a plumber that if I wanted one of those, I would also have to replace my 1/2 inch gas line with a 3/4 inch line which would add considerable cost to an upgrade. check on the requirements of the heater you want and the size of your supply line to know if this will be an issue.
I am also interested in these tankless heaters... What concerns me is the minimum flow rate to trigger the heating action... Would a faucet that was not on full blast (ie a trickle for washing dishes) be enough flow to trigger the heater?
This is one of the specs the manufacturers publish, I've seen 0.5 gpm,
0.66 gpm, and 0.75 gpm. That's the hot water portion of the demand, so 1 gpm of warm water might only be 0.6 gpm of hot water, say.I believe a kitchen faucet is required to be max 2.5 gpm these days. So you couldn't run a trickle, but could still run it fairly low. Perhaps someone who has one of these tankless water heaters could comment?
Cheers, Wayne
I've had a Takagi for a couple of years. The only problem with faucets is it takes longer to get warm water than with a tanked unit (the heater doesn't come on "full bore" with at low flow, so it takes longer to heat up the heat exchanger). Never had a problem with it simply not triggering.
Turn on flow rates differ but are around 1/2 - 1 gpm so it will not trickle out hot. I have a small 117000 Bosch and the savings are worth it , it needs a 1/2" gas line to 10- ft. then 3/4 if further away. Larger 2 shower units need 3/4 line. Bosch Takagi and Rinnai are the main names and most are made in Japan. My unit will heat easily 34f incomming to a hot shower without being set on high. The larger more efficient units will really handle 3 showers. Ratings are key, the gpm and temp rise. Takagi has a new unit that is the highest efficiency made at 92% Ng
The T-H1 has got some killer specs, but at three times the price of the T-K2, I sort've doubt they're aiming at the home market...
Tankless water heaters were a standard "low end" product when I lived in Asia (~15 years). The better apartments had hot water tanks.
My experience with gas-powered tankless heaters is that they are, indeed, a low-end product, where the primary advantage was that they didn't take up any floorspace. (The average apartment in Asia was about 600 sq ft total, so every inch of space was used.)
People on this thread are asking the right questions, especially about flow rate. In my experience it was difficult to balance temperature and flow rate; when you decreased the flow of hot water to get a comfortable temperature, you could reach a point at which the gas suddenly cut off and you went to full cold. Given the low cost and reliability of conventional hot water tanks, I don't think the pay back period of a tankless heater is persuasive.
I suspect installing a tankless water heater is a little bit like buying a diesel car, being responsible for the two happiest days of your life -- the day you first start to use it, and the day you finally get rid of the #%$&^%# thing.
When we remodelled, I chose instead to put an additional hot water tank adjacent to the new bathroom, which gives me almost instant hot water. Regards --
Temperature and flow rate is now computer controled with a full modulating gas valve so temp stays the same when it is on from start to full flow. Older units lacked this. at very low flow it will turn off, that is a drawback but it doesnt bother me as all my faucets are low flow so I ususly just turn them on full. My payback will be 4-5 yrs switching out an electric tank. I have no complaints after 2.5 yrs.
Yes - the new tankless units are nothing like the low end stuff we saw in the past in Europe. Today - the new units are computer controlled - and are relatively bulletproof. Some are 92% efficient. They have digital wall gauges that allow you to tune in the temp you want within one degree.
I am planning to replace two 50 gallon electric water heaters with one unit - Rennai - Bosch - Akagi.
My city give a $450 rebate for converting and electric water heater to gas - so I may put two in the house - that way I have one as a back up :-)
Harry
We put the bigger bosch tankless water heater in our new house last fall---hard to compare savings without a base line but sure do like never running out of hot water! Downsides are that it takes awhile to get hot water(wife complins!) and sometimes at less than full throttle hw is lost temporarily--but can put 400gals of HW in the hot tub that is a plus for us for sure!
When we build the next place will bet that swmbo will make sure that there will be some form of instat hot water in HER bathroom! ymmv
Buzz
The old man on the radio is a huckster pitchman. Don't buy anything he sells.
Tankless heaters now have computerized controls that eliminate the wide temperature fluctuations you experience with the older models. I was also in Asia during that time frame and remember how quickly I woke up after taking a shower where the water temp swung 40 degrees.
Really, you know this how?
He sells that $500 boom box. That vacuum cleaner. Tankless water heaters. Stuff for suckers who wanna believe.
The Rinnai has a continuously modulating gas valve, goes from low to high flow with outlet temperature + or- two degrees. I don't know what the minimum flow is. They do have a very large size burner, 199,000 BTU/Hr max. You will need a large gas pipe for that. Not simple to work on either. There are screens that can clog up from crud in the water. Very efficient however, no standby losses either. Some good & some bad to them.
Stretch
His $500 boom box is now over a grand............it's like 1200 bucks or more.(this model also has a 5 disc changer with it I believe)
The guy that sells the vaccum cleaners is a different guy. I always hear that guy trying to throw in a free $100 iron too.
Tankless water heaters are not sold just by "the old man on the radio" so I feel like they may have some potential. some others posting real life experiences here are making a good argument "for" tankless........at least as a supplemental piece. I am considering a small one under the sink, as My home is Slab foundation and all the water has to go through a cold slab to get to the kitchen.............more than halfway across the house. Takes a while.
Remove "YOURPANTIES" to reply
MUADIB®
If there is a water shutoff, you can drain a tank model to get some water for your personal use.
My neighbor has a big house. He had two gas tank water heaters. He replaced them with two "takagi" tankless water heaters - had them installed for $500 each. Now this guy is a wealthy fellow and money does not matter to him - service does. The tankless water heaters produce endless instant hot water - no lag - no nothing - turn the faucet on - hot water comes out now. He can have four showers running at once and the hot water still does not run out.
The units are very small - less than 2 x 2 x 1. they do not require electricity - so you have hot water even in a power failure. They have a battery igniter.
A restaurant down the street has one. They do piles of dishes daily. They depend on that "rennai" tankless water heater. It does a great job. their business would go down without it. they have been using it two years without one down time.
Also - since we leave our home a lot - we will not be heating a tank of water and wasting energy keeping it warm. When you are away - everything is off. It only turns on when you turn on the hot water faucet. I am going to install my tankless heater on the outside wall just 4 inches from my showers.
Also my city will give me $450 for every electric water heater I replace with a gas one - so this is an easy decision.
The new technology in tankless water heater is fantastic. Yes - conventional water heaters are cheaper than tankless - but but tankless are cheaper to run and much more efficient.
I am going to install one or two.
Harry
OK, so you are saying he is a credible guy then? That tankless water heater is made by a very reputable company (Rinnai) and happens to be work really well.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.