tankless water heaters

[IndyGunworks]

I am considering going tankless w/ my new construction house that we are planning to start building this spring. Anybody have any idea of the average number of gallons of propane one of these things use?

also any recommendations on a budget friendly unit? Looking for direct vent out the concrete basement wall.

Also, how much of a PITA is it with the min of .5 GPM flow before you get hot water? I have no experience with these things but I like the idea of saving on the monthly bills, even if it costs me a bit more up front.

 

[Mr. Habib]

I have one. It replaced a high efficiency direct vent tank unit. Ours is on natural gas, so no idea about LP. It will depend, obviously, on your hot water consumption and temp. I worried about the minimum flow requirement also, but it has never been a problem. A lot of the cost difference of tank vs tankless is the higher installation for the direct venting. With a new construction that should be minimal. This is the one I have. RL94i Tankless Water Heater | Rinnai

 

[churchmouse]

Look at all of the maintenance they require. If you are on a well at the new place you will have to filter and or treat the water or you will hate the unit. They will plug up with lime if not cared for.
I would not do it. JMHO from experience.

 

[SMiller]

I researched the crap out of switching to one and from what I read they are slow to get hot water to the tap and nothing but problems, my best guess is to go large, well insulated, dual stainless elements, with the self cleaning tank and hope for the best. Study/study as there is a lot to be learned, might check into geothermal?

 

[IndyGunworks]

I have looked into geothermal, and the return on investment is just not there for me. I will be using a heat pump integrated into a standard high efficiency propane furnace. Shouldn't need to use much propane cept for the really cold days, and then I plan on adding an outside wood burning unit eventually.

I plan on a water softening system that that will be inline before this. Probably will have it inline before the pressure tank as well that way the pressure tank will last longer.

 

[churchmouse]

I have looked into geothermal, and the return on investment is just not there for me. I will be using a heat pump integrated into a standard high efficiency propane furnace. Shouldn't need to use much propane cept for the really cold days, and then I plan on adding an outside wood burning unit eventually.

I plan on a water softening system that that will be inline before this. Probably will have it inline before the pressure tank as well that way the pressure tank will last longer.

One thing to consider on geo-thermal that is often over looked is how long the equipment lasts. The life span is double or more over direct air cooled machines. The efficiancy is exactly what they advertise . Air over units do not always perform up to standards. They are subject to the heat and poor ventilation etc. A geo is supplied the same temp water near year round and never struggles on design days. They live a very happy life compared to air over machines therefore increasing design life span.
If you have an air over heat pump any money you save will only be spent on repairs/replacement in 10 years or so. There are no savings realized by running a pump. I have been in the trade longer than I care to admit and was around when the "Pump" was a big deal.

I hope you have good luck with yours.

 

[IndyGunworks]

my parents have a heat pump and its going on 15 years for them as far as I can tell the cost of the geo at 18000 even with the tax credit is not enough to to make it worth the extra 200 dollars a month on my mortgage

 

[churchmouse]

my parents have a heat pump and its going on 15 years for them as far as I can tell the cost of the geo at 18000 even with the tax credit is not enough to to make it worth the extra 200 dollars a month on my mortgage

The initial install is brutal.

If Mom and Dad bought a new one today they would be having it repaired /replaced in 8 to 10 years.
Keep the outdoor coil and filter clean. Best thing you can do. If you suspect it has an issue act right away. Again, best thing you can do.

 

[grasshopperlegs]

I have a tankless electric water heater that I bought 7 years ago. It cost me right around $300 for it. It has a 50 amp use and it has worked great for all these years. I saved close to $30 dollars a monthe on my Electric bill. My bath room is at the other end of the house (Ranch Home) and it gets the hot water there just as fast as the old water heater. It takes up less space and it doesn't heat the water all the time like the old one did. I just love it. I do have a water softener on it but mainly due to the iron I have in the well water. It works for me but some people don't want to change from the old water heaters.

 

[rlspach]

I have an AO Smith tankless on LP and well water. I've had it for 1 year in a new build. We had one problem with maintaining constant temperature. Fortunately the builder was very experienced and had seen this before - something related to the chimney. They changed the chimney very minor. Ever since it has been AWESOME. Unlimited hot water, heat to the tap just as fast as a tank.

I haven't had it long enough to know if the well water will be a problem. Also, I don't have anything to compare with relative to how much LP it uses. The installer said if we use a ton of hot water (he said a houseful of women lol) then it might be more expensive. That might just be because you're not running out of hot water though so it encourages longer showers.

Personally I'm never going back to a tank just for the convenience of not having to wait around for hot water especially when I have company, etc.

 

[mdmayo]

I thought I'd read somewhere that the on-demand units should be placed as close to the faucets as is reasonably possible? I have a friend up in northern Michigan that has two smaller electric on-demand units; one is under the kitchen sink, and the other in the linen closet near the bathroom. He claims they are saving him 20% on overall utility as compared to NG traditional units.

 

[Mr. Habib]

For the small on demand units, that's right. This is a whole house tankless unit. Similar idea, difference of scale.

To the OP. If you do go with a tankless unit and are worried that you will have to wait for hot water at faucets that are far away from the it, there are some that are designed to control a recirculating pump that will help that.

 

[IndyGunworks]

I am not worried about having to wait for hot water, I am worried about it not giving me hot water at a lower flow rate. IE, I want just a trickle of hot water to keep the cold from being so cold and something w/ the pressure changes and caused the hot to kick off. more or less I am worried about fluctuation in hot water more than wait times.

 

[buffalohump]

I have an aquastar whole house LP tankless water heater, & One for my Mom's appartment. "bout 12 yrs old now. no problems, no upkeep, run soft well water through it. I love it. Hot water is instant & lasts 'till you run out of gas. I would buy again. 20 years expected life. I read the neg posts, & Don't know why there is so much trouble.. BH

 

[terrehautian]

If you have hard water, they will not last. I will say that when I been on mission trips with Samaritan's Purse with a shower trailer, they have had on demand tankless systems. Even with six showers going almost constant for hours after a days work, they never ran out of hot water (minus running out of gas).

 

[rjc2rjc]

I am considering going tankless w/ my new construction house that we are planning to start building this spring. Anybody have any idea of the average number of gallons of propane one of these things use?

also any recommendations on a budget friendly unit? Looking for direct vent out the concrete basement wall.

Also, how much of a PITA is it with the min of .5 GPM flow before you get hot water? I have no experience with these things but I like the idea of saving on the monthly bills, even if it costs me a bit more up front.

in a residential home the .5 gpm will most likely never affect you. really the only time I have ran into a problem with the .5 gpm was in a restaurant. they used a spay handle in there dish area and that was all they ever used. the spray handle put out hardly any water what so ever so they would run out there whole storage tank before they figured out what was going on. had to train them to run another faucet wile they were using the spray handle. generally all water faucets in a house are 2.5 gpm. so you should be fine. as far as propane consumption. That all depends on your hot water usage. less hot water you use the less propane you use. Navien is what my wife recommends they have a built in buffer tank and pump. plus they vent in pvc and not the stainless that others vent in. and let me tell you the stainless vent can get expensive. And just so you know I have been plumbing for 16 years and my wife has worked for a plumbing supply store for about that many years as well. So I am not just blowing smoke up your butt. lol

 

[IndyGunworks]

in a residential home the .5 gpm will most likely never affect you. really the only time I have ran into a problem with the .5 gpm was in a restaurant. they used a spay handle in there dish area and that was all they ever used. the spray handle put out hardly any water what so ever so they would run out there whole storage tank before they figured out what was going on. had to train them to run another faucet wile they were using the spray handle. generally all water faucets in a house are 2.5 gpm. so you should be fine. as far as propane consumption. That all depends on your hot water usage. less hot water you use the less propane you use. Navien is what my wife recommends they have a built in buffer tank and pump. plus they vent in pvc and not the stainless that others vent in. and let me tell you the stainless vent can get expensive. And just so you know I have been plumbing for 16 years and my wife has worked for a plumbing supply store for about that many years as well. So I am not just blowing smoke up your butt. lol

I looked them up and was shocked at how many bad reviews they have gotten. I don't think I can spend 1500 bucks w/ a company that has THAT many bad reviews out there.

 

[grasshopperlegs]

Ok: I have a titan electric tankless water heater. I have said before that it is over 7 years old and no problems. I don't have to worry about gas or flue pipes ect. I got it surpisingly off of Ebay and I just love it. I do have a water softner so I know that helps.

 

[DocIndy]

When we were doing the HVAC for Starbucks, we were stuck installing the stainless flues for their tankless Noritz water heaters. I was amazed that they were using them. The stainless flues were not cheap, but the newer ones get PVC. I have been looking at them for my house to free up space in the mechanical room. I found out you need to flush them once a year to clean the heat exchangers. Not a huge hassle, but still needs to be done to prolong the life.

 

[IndyGunworks]

I am planning on have a pretty nice water softening system inline before the heater so I am hoping to avoid annual flushing, but as long as its something I can do myself I don't mind.