My 40 gal LP water heater just sprung a leak. We have hard water and water heaters are averaging 9years here. So now is decision time. I’ve been thinking about converting to tankless hot water. I know it’s expensive up front but the current tax credits are helping make it attractive. Are there any down sides? The kids are grown and no longer at home…it’s just the wife and I. Seems wastefull to keep 40 gallons hot all day.
Any brands to avoid? I’ve been installing my own LP water heaters….is this a DIY job or do I need to hire a pro? Some friends had their gas company install a Rinnai and they are happy. Home Depot sells Rheem……good deal or better to buy from a plumbing supplier?
Thanks for your good advice……I’ve got to jump on this quickly, cold showers get old fast.
Replies
I like my Takagi. Bought it on ebay from an authorized seller in Ventura,CA. Super helpful woman, full warranty, all venting supplies available through her.
I have had it for 6 years and the only downside for me is that it takes 3 sec for the burner to kick in after sensing flow and then it will shut off if you are just letting the water trickle. When you realize the flow is too low you have to wait ten seconds or so for the burner to kick in and purge the line of cold water.
This was irritating enough I put a 4 gallon electric water heater under the kitchen sink that the hot water from the tankless feeds.
Aside from this I love it.
Be sure you have a large enough gas line otherwise it may not be able to fire the burner at its maximum capacity.
Karl
Unless you plan on being out of town frequently, I'd say get the tanked model replaced.
In short, a Rinnai uses too high of a low flow detector (3/4 gpm), a 1/2 or lower is better - such as a Tagaki T-3.
The cost of installation (including special SS venting) will more than double your cost of hardware. Hard water will likely require more frequent flushing with an acid solution to keep the innerds clean.
And it'll drive you crazy whenever someone lets the hot water run unnecessarily. Big learning curve for the whole family, not to mention guests. (Seriously, my mother will not change her hot water usage behavior. This MUST occur for savings to be seen.) You'll likely become a hot water "hall monitor" to keep your guests from using it the wrong way. And you'll lose friends.
Hey, I'm only speaking from experience!
I've been reading some of the discussions on the pros and cons of tankless and it seems it isn't as clear cut a choice as I thought. My only experience with tankless was many years ago at work, but it mirrors what Karl said. I was hoping the technology had improved. A trip to HD for a tank and quick fix is looking better.
unless ya soften the water you'll gain nothing...
hard water will be the early demise of the tankless...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
Only if you go several days at a time without using hot water will tankless save money.
When the tankless burner lights off, you will need a high volume of gas to feed it. This may require re-piping unless it is very close to the LP tank.
Small water tubes (like a car radiator) bring water through the flow of hot combustion gases from the burner. Small tubes plus hard water = clogged tubes after a while and loss of efficiency.
on sat and sun and in the evening your parts store is probably closed, less Lowes carries your brands parts
You probably meant to post this to someone else.
BruceT
Thanks for the replies......so here's what I'm hearing:
Tankless becomes a better deal if you use it less. Hard water will clog it/require cleaning the exchanger. Parts are harder to find, especially on weekends. Necessary to upgrade gas line to 3/4" and get SS venting. Possible adjustment of water habits. Possible that flow sensor is a pita with low flow.
BTW, the current tank vents directly into the chimney flue which it shares with the oil fired boiler. Would the tankless vent into that without problems?
I read in another thread that the standby loss of the tank models is negated during heating season because it's contributing to heating the house. Even with the tax credit of 30% of cost (up to $1500) it sounds like the payback is quite a few years.
I'm weighing all that against the fact I can run up to Lowes tonight and pick up a Whirlpool 40 gal for $389 and install it myself, an option that is sounding better and better.
the current tank vents directly into the chimney flue which it shares with the oil fired boiler. Would the tankless vent into that without problems?
maybe...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
"Some days it's just not worth chewing through the restraints"
BTW, the current tank vents directly into the chimney flue which it shares with the oil fired boiler. Would the tankless vent into that without problems?
Doubtful.
Most fuel burning tankless setups are Cat III stainless venting... Noritz has released a model that vents with PVC pipe.
Stainless venting is expensive. Very expensive. Fittings are even more. So expensive that you will want the tankless as close to an exterior wall as possible (unless you live in a ranch with a straight shot out) and then you are dealing with moving water and gas piping.
Of course, that gas piping needs to support the additional BTU requirements. Sticking a 200k btu burner on the end of the typical residential run is just asking for trouble when the piping was originally sized for a 40k btu burner.
It is doubtful you have forced combustion air ducted to the boiler, so adding another 200k btu appliance is going to create issues. Most newer tankless setups use a concentric (pipe within a pipe) piping system because of combustion air problems.
The numbers you need to pay attention to are the GPM (gallons per minute) and degrees of temperature rise. Some manufacturers put a high GPM on the box... but the fine print reveals a low temp rise. If you know your average supply water temperature, you know how hot the water gets.
Things like showerheads and most faucets are regulated to 2.5 gpm, and someone rarely uses full hot, so tankless works fine. Other things like tub spouts and clothes washers are not regulated, so those pull more than 2.5 gpm unless the flow is regulated with an additional ball valve.
If your water is so bad that it eats the piping, then think twice about a tankless unless you do something about the problem.
There are special valve assemblies available to allow easy flushing of the tankless heat exchanger. Only a small pump and a couple of garden hose cutoffs are required in a 5 gal bucket of solution.
If your water use habits stay the same, the only savings comes from eliminating the tank standby losses. Buy a good tank with some insulation instead of the cheapest thing on the shelf and you will save money.
If your water use habits change with the availability of limitless hot water, you will see zero savings, and probably spend more.
Hi Tommymc,
So now is decision time. I've been thinking about converting to tankless hot water.
It is not my intention to sound crass or short with you, simply that switching from tanked to tankless are different in so many ways that making that decision spur of the moment is "not" a wise move.
My first recommendation when in urgent mode is to replace what you have with what you already know and plan for a "potential" change over the next nine years so you will be ready when the time comes.
You also have not filled out your profile information so it's hard to make solid recommendations based on a non existent location. Your local climate can make a difference in choice so please take the time to fill it out.
My second recommendation is based on the fact that we went tankless on our current home when we built it. Paloma tankless direct vent outdoor LP unit purchased from Designer Plumbing out of FL. I love it and would do it all over again. It's a 7.4 gpm unit and I recommend attaching the electrical portion to a 650 va UPS in case the power flickers you don't get a burst of cold water and the UPS will have built in surge protection to help protect the electronics. In thinking ahead we installed dual handle faucets. Single lever units often get moved to the "warm" central setting and for short hand washings, the unit ends up running and you're finished washing before the hot portion reaches the sink. This is a big waste on tankless units and somewhat of a waste on tanked units so using dual lever faucets is a good idea regardless.
In the mean time there are numerous previous discussions here on BT where you can search and gain additional insight prior to making a future decision.
Pedro the Mule - Same but Different, understand the details first
Thanks Pedro for the insight. I'm in central VT, in a rural area. Our water comes from a drilled well. I've never had it tested for anything other than bacteria, but it seems hard....and does a number on both the pipes and water heaters. You're right about not making urgent decisions, no offense taken. The worst part is I should have been on top of this and had a plan...it's just that there are so many other things that need attention too.
Good point about the single lever faucets. The only ones we have are in the showers, so probably not a big issue here. I've been reading other threads here and see that there are more pros and cons than I imagined. It seems like there isn't even a clear concensus that there is real savings going tankless....which is the reason I'm considering it in the first place.
Hi Tommy,
It seems like there isn't even a clear concensus that there is real savings going tankless....which is the reason I'm considering it in the first place.
My primary reason was based on "never" running out of hot water. We were on a 40 gal. electric for my entire life. Always ran out for one reason or the other.
So basically as long as I never ran out of hot water and it didn't cost any more to operate over it's expected lifetime......that's all that mattered. I've ran the numbers and found that under full time use our unit costs about 60% of what an all electric water heater would in our area. Understand that I bought a huge LP tank that'll last two + yrs between fill ups and I simply watch the market and buy when it is somewhat reasonable.
As we reach closer and closer towards retirement, we'll spend even less time at home and the savings will be even greater. So out the gate I'm doing better and that will only improve. It sounds as if you are already on gas so your rates of operation are probably going to be close to the same with the tankless costing a little less to operate but the difference made up by the cost of the unit......poor memory.....I think with all piping fittings, UPS, unit, shipping etc. I came in right at a grand.
Pedro the Mule - Ahh warm water non stop on the fur is delightful
have had two.
bosch aquastar NG, bought from lowes in 02' to replace old elec 30 gal. could not quantify the numbers now but that thing paid for itself in prob. 5 yrs. (only lived there 2 more though). but, more importantly it "felt like it paid for itself immediately. Lower elec. bills and we never ran out of HW, a problem previously. cost about $900 with all parts, sef install.
New house, put in a Takagi T-1 mobius. works good, there is a wwaaaaaaiiiiitttt for the hot to hit, there are ways around that ..... more $$$. probabaly haven't saved anything, more than likely has cost me because with three little ones and a northern climate, warm sprinklers are now used as well as pools. plus daddy probably takes much longer showers than if he knew ther'd be no hot water left for momma. cost $2000 with unit, remote, ss,vent, and self install.
Tankless. You'll save money going from elec tank to gas tankless. otherwise your only doing it for convienence (luxury). my unkowledgable advice :)
Try a SEISCO electric. We have one & it's great. Been using it for 6 yrs, now. Never run out of HW. Run washer, dishwasher & shower all at same time & have satisfaction. Cost about $600 to buy. Needs 200 amp svc at least to support. Electricity is cheaper here than LPG & we don't have NG. Nawth Jawja, in the hills.DonDon Reinhard
The Glass Masterworks
"If it scratches, I etch it!"
I hate tankless. I could never get a trickle of hot water to shave or rinse dishes. That's why many people have to add a small tank in series with it. I did a price comparison for a few years before I tore mine out -- and there was no cost savings for my home.
Some products never live up to their hype.