Hot Water Tank or Tankless

[wackysue]

I need to replace my hot water tank and the electric tankless hot water heaters are very appealing but different from what I have always grown up with. I need some help making the decision. I have a family of 5 to keep in hot water. Can you give me some advice?
Wackysue

[jadnashua]

If your house is set up for it, they do work. Keep in mind, though, that you probably will need to expand your gas supply line and have provisions to provide combustion air. The things are rated at degree rise at certain volumes. The more water you request, the colder it will be since you can only transfer so much heat in the time the water passes the coils. To meet the requirements of say two showers running at the same time, you might need two of them in series (not all of them can do this). Maintenance can be expensive and parts are not stocked everywhere. A gas tank type or electric can be serviced with parts from almost anywhere.

[Gary Swart]

This topic is frequently brought up here, and the majority of plumbers do not advocate tankless. I would suggest you search the archives and read the comments, but it seems the major drawbacks are inital cost, difficulty in finding qualified repairmen, and in the winter when water is very cold, you may not have water as hot as you would want. (this would depend somewhat on your geographic location)

[kordts]

If you go tankless, go Noritz. If you need more than one, you tie them in together by plugging a cord in from one to the other. They are expensive, but worth it. Their appeal is not in saving money, but endless hot water.

[master plumber mark]

http://www.weilhammerplumbing.com/houseofhorrors/

[Dunbar Plumbing]

Got a call for one sunday and it was a State Aurora tankless. 2 months old and the plumber who installed it didn't know how to service it, I don't know how to service it and NO ONE on new years day knew how to service it. The only thing that mattered was that the customer was without hot water until santa comes back with a 1-800 number and UPS to send the parts by return sleigh.

Who knows; this guy still may not have hot water. There are no reps in this area to deal with all of these new up and fast coming products made in china. The one he was telling me of had a 1" gas line and two double pole breakers in combination of each other. A very VERY expensive defect (whoops device).

He was gloating about it though.......said he could take a hot shower for hours.

I, like the ******** I am, asked if he really was that dirty....???

[hj]

Jadnashua;
He said it is an electric heater, not gas. electric tankless are an expensive proposition to install, given the size of wires, or multiple wires, they require. Then you have to pay the electric bill when it comes.

[Bob NH]

I need to replace my hot water tank and the electric tankless hot water heaters are very appealing but different from what I have always grown up with. I need some help making the decision. I have a family of 5 to keep in hot water. Can you give me some advice?
Wackysue

Where do you live and how cold is the water supply in the winter?

5 GPM x 60 min per hour x 8.34 # per gallon x 70 degree temp rise / 3413 BTU/kWhr = 51.3 kiloWatts.

51,300 watts/240 Volts = 214 Amps. That's just for the water heater.

It is almost certainly more than the whole electrical service for your house.

Even 2.5 GPM for a minimal shower requires more than 100 Amps.

At 2.5 GPM it will take 16 minutes to put 40 gallons in a bathtub and cost about $1.00 for electricity at the rates in my part of the country.

You can adjust it for your own GPM requirements and temperature requirements.

I have been in showers supplied by electric instant water heaters in Europe where they are fairly common. I have NEVER had a satisfactory shower from one.

[geniescience]

Sue, you are getting good value here. Bob knows how to calculate. The temperature of your incoming cold water supply is a very important factor, and in winter water can be very cold, depending on where you live.

Where do you live and how cold is the water supply in the winter? .... 16 minutes to put 40 gallons in a bathtub .....

I have noticed that electric tankless HW heaters are noisy. It sounds like friction. Gas ones are less noisy; they sound more pleasant to me; reminds me of a gas stove or fireplace.

[Cass]

Install a storage tank type heater, not the tankless, and get one with high wattage elements for a quicker recovery and you will be better off in my NSHO.