Hello chemocurl,
Thanks for taking the time to search the subjet for us.
Blessings
Martha

If the question is 50 gal electric heater vs. electric tankless, go with the 50 gal tank. There's virtually no savings with an electric tankless and the cost in electrical service is too high.

If you had gas available, it could be a different story.

jakethewonderdog,
Thanks a lot for your help!
DH red it and he decided to follow your advise. He also read all the comments in the link
Thanks

I'd say no way to a tankless! They tout savings because they supply water on demand, but it doesn't really end up that way. A) they're expensive: $1800 or so minimum; they require stainless steel venting which usually costs more than a conventional 50 gal water heater; not to mention installation costs; also the BTU's are significantly higher around 75,000 if I remember right v. 40,000 (for a good 50 gal) so you're using almost twice as much energy to heat the water on demand. To me the efficiency argument doesn't make sense. B) They're not designed around our lifestyle. I've been to several countries in Europe and Central America where they use tankless water heaters...they're only used to supply a shower (no hot water anywhere else in the house). Here where we have dishwashers, washing machines and hot water at every faucet a tankless water heater is not a realistic solution. If you have room, a much better solution is to plumb two 50 gal heaters in series. That will run you about $700 or $800. Get a Bradford White. Best heater on the market

If you read the first post closely as Jake did, the question was tankless or 50g electric? No mention if the tankless (better coined an on-demand) would be gas or electric as the choice to keep it even. While electric on-demand is possible the restrictions of use and electric service required would make it cost prohibitive for most.

Plbg101, seems you have no experience with gas on-demand heaters is my guess. Please tell me where you can get 2 50g gas htrs for $800 while the on-demand is $1800?

Your numbers are skewed abit. I can show you where a 195,000 gas heater with SS vent kit can be purchased for around $1200. Now price 2-50g gas HWH with the new flame safeties and the price is quickly closing in.

Having had an on-demand for over 15 years and on my 3rd unit now, only because I moved into a new house last year. I am totally satisfied. With 3.5 baths, Jacuzzi, workshop with hot water, I am as most that have one, happy with it.

To each it's own, some people still prefer standard TV's over flat screens, still listen to AM/FM radio, use chlorine in their pool, shop for bias ply tires, 3 speeds on their bike and wear a leisure suit to church, thatÂs your prerogative.

You need gas or propane for a tankless heater. The electric ones just don't produce enough BTU's. Instant electric water heaters only work in areas where the incoming water temp is over 70 F all the time, like the tropics.

A whole house tankless heater fired by gas or propane produces at least 175,000 BTU. You need a big gas line, at least 3/4" and close to the service meter. My Bosch Aquastar 250 tankless can raise the incoming water temp from 50 F to 140 F, a 90 deg rise.

The installation is critical. 1. You need enough gas, 3/4" line minimum. DO NOT use any flex lines in the connections, they restrict flow.
2. Special exhaust vent required- stainless steel Type A vent. Z-Flex is the most common brand. You can't find these at HD or Lowes, even if they sell the tankless heater (go figure) you have to get them from a specialty plumbing supply or online.
3. Air intake vent- Needs outside combustion air. Use the Z-flex vents. My heater is in the garage, and the installation manual says the outside air is not necessary in a large room like the garage. Well, the dusty garage environment clogged up the burner, and the heater started failing intermittently after 2 years. I disassembled the whole thing and cleaned out the dust, added intake venting from the outside, it works great now.
4. Isolation valves- The boiler unit has to be flushed once or twice a year with white vinegar to remove water scale. You need the isolation valve kit to do this, get it from the same place you get the venting supplies.

These 4 points are critical to properly install and maintain a gas fired tankless water heater.

The other main complaint from consumers is the hot/cold fluctuation. Each time you turn the water off and back on the boiler lets about half a gallon of COLD water go through before it can get the flame going strong enough to heat the water up. This sucks when washing dishes. i solved this problem by adding a 6 gallon electric water heater in line directly after the tankless. I keep the thermo set at 110 F on the electric and the boiler on the tankless set at 140 F. This has completely eliminated the hot/cold fluctuation. The electric heater uses very little energy because it has 140 degree water flowing into it. When the water is first turned on, the half gallon of cold water goes into the 6 gallon tank, mixing with the 110 F water, but quickly the boiler gets up to 140. The effect is a gradual temperature rise as you take a shower, rather than temp loss. I also have thermostatic shower valves, so getting scalded is never an issue.

Adding the small electric heater has made all the difference in the performance of my tankless heater. I do not recommend installing one without. We can easily run 2 showers, or a shower and washing machine, or shower dishwasher and sink. (Water saving faucets and showerheads help) Where I live the cold water is always COLD but the tankless gets the job done.

Aidan m, you said you installed the small electric after the tankless. I have an electric tankless and was going to solve the problem for my wife by installing a 95% efficient 40 or 50 gallon electric tank (to be eventually used for solar pre-heated water) and setting the temp to say 80 degrees before the tankless. My electric tankless (I installed upgraded electric service when I built the house and have inexpensive electric rates)would then only have to heat from 80 degrees to the 110 instead of 52 to 110, using less water in the process. My garage is well insulated and the new energy efficient tanks should greatly decrese heat loss, especially when warming only to 80-85 degrees.

I know I wouldn't save any on the electric bill but what little additional cost there would be is miniscule compared to momma not griping. If it were just me, the system would stay as it is. Works fine for me. I have a friend who also has tankless and his wife also complains about temp fluctuation and how the unit performs when rinsing dishes (on/off at the tap).

No problem with showers or anything else. There is a learning curve but I'm very satisfied with the product. However...I have to live with momma.

One other nice thing about my tankless water heater setup is to be able to fill the 300 gallon spa in less than an hour and use it right away

Instant electric water heaters only work in areas where the incoming water temp is over 70 F all the time, like the tropics.Interesting. I suppose the central Texas coast qualifies as tropical ... however, my incoming water dips to 37°F to 40°F during the "winter" season. I've not had any trouble getting sufficient hot water (high as 135°F to 140°F if desired) out of my electric tankless unit.

BTW, a local building supply carries a couple sizes each of Bosch gas and electric tankless ... none are anywhere near $1800.

Mine cost $827 delivered to my doorstep. Had to upgrade electrical service while the hosue was being built and that was $1,000. However, natural gas would have set me back nearly $3,000. My electrical rates are more favorable than natural gas.

Hi all.
We have a 2nd floor bathroom in our New England home. It takes forever for warm water to travel up there from the water heater in the basement. The water runs cold for about 5 minutes!!! Would a on-demand electic hot water heater be a good solution for this problem? Several times guests have assumed we had no hot water on the second floor.

Cayuga:
The on-demand would help solve the problem if it was near the location in question, and was not replacing your main water heater. Another option, and possibly less expensive, would be insulating any pipes you can, and putting in a recirc system, such as a Laing Auto-Circ or a Grundfos Comfort Pump.

A common misconception is that on-demand or tankless automatically means instant hot water at the faucet ... which it does not. Hot water still must travel-the-distance through the plumbing from the water heater to the point of use. If the tankless unit is installed at a central point in the house, it'll work the same as a tank in regard to getting hot water to the more distant points.

The advantage to electric tankless is that they are very compact and require no venting. A small-capacity unit can be installed in a distant or 2nd-floor bath to take care of delays in getting hot water up from a basement or central water heater.

I agree that electric tankless can have an application such as point-of-use at a distant faucet. However, the original question was about a whole-house heater.

Plumbing101-- I'm sorry, but most of your information just isn't factual.

There is a LOT of disinformation on these forums about on-demand tankless units, ESPECIALLY the electric units. First, energy cost savings is NOT a reason in itself to make the switch. No reason alone is sufficient. It is the total package, in light of your particular lifestyle, that will dictate the pro-con outcome of the decision making process. First, tankless units save space -- a lot of it, especially electric units that do not need to be vented. In Texas we have no basements, so that can be an important issue. Second, an electric unit is unlikely to blow up, unlike anything using natural gas. Third, there is an endless supply of hot water, which in a successive-morning-shower household like mine, is a really important issue. And finally, yes there is some documented comp fuel savings (electric tankless over electric tanks, or gas over gas), that is really offset by the added initial cost of the unit plus upgraded electrical service or gas supply line sizing. Moreover, there ARE full-house electric units out there that provide plenty of water, unless you plan on taking two showers simultaneously while also doing your laundry and running the dishwasher! And if that's your bag, you can run 2 or more electicals together. Or get a really big gas unit.

Bottom line, nearly every nay-sayer of tankless units ignore the pros and focus on a single con - cost, cost, cost. Well, we all don't drive a Ford Focus for a reason. Some of us enjoy our Buicks, Porsches or Camrys even though another car would get us from point A to point B cheaper while using less fuel etc etc etc.

Full disclosure: I have a Steibel Eltron Tempra 36 whole-house electric unit. Love it. My electric bill went up nary at all.

We have a gas tankless unit ($600) in the bathroom in our new extension. Works great, except when the cold water gets warm in the summer. Then we don't draw enough hot water for it to turn on (need at least 0.5 gal/min), but we open a faucet a little.

I think they make great sense for point-of-service applications. We were less convinced about replacing the old-fashioned whole house unit. Perhaps when it fails. It's a long way from the heater to the old bathroom. It's even longer to the new bathroom, which is one reason we think our savings are greater with the tankless.

BTW, while I agree with most of what bradleyj says, major appliances, whether gas or electric, are designed to be UNLIKELY to blow up. While some houses have blown up due to gas leaks, many more have burned down due to electrical problems, though a major appliance causing either catastrophe is extremely rare. It just doesn't seem to be a major consideration. Carbon monoxide poisoning is much more common than blowing up, though it's almost always due to worn out or improperly installed equipment. A carbon monoxide detector is a fairly cheap safeguard.

mkrkmr..I find you advice regarding carbon monoxide to be very good, however I am left wondering why you didn't follow your own advice when you installed your water heater in the bathroom?

The plumbing codes prohibit installing any gas combustion appliance in a bathroom, bedroom or any room which opens into a bathroom or bedroom.

mkrkmr,

Try turning the temp setting *lower*. If the tankless serves only the bathroom extension, then you don't need 120°F or 130°F water there. Set it at the temperature you prefer for showering, no higher. 103°F to 105°F for example. Then you'll run only the hot water for showering, without mixing in any cold, which will increase the flow-rate through the tankless, thus helping to eliminate your problem of it not coming on. It should modulate the burner accordingly to maintain the target temperature. 105°F may be a touch low for tub baths, so you may have to increase the temp a little for that.