What Heater Blues

[Victor Stearns]

Greetings Creekers,
So I will need to replace my 40-gallon tank type water heater soon.
I have a brother who is a plumber, so maybe just a beer and lunch to get it hooked up.
But I was looking at maybe changing to a tankless unit instead. You know, endless hot water! Important with 4-people in the house. I already know the tank type is around $400 and the tankless is $1800. Doing the cost anaylsis, I am not sure if it makes sense to spend the extra $$$ for endless hot water. The tankless unit is better than 90% efficiency, and yes I am for going green when it makes sense.
So how about your 2-cents.
Thanks for Lookin and Keep making shavings,
Victor

[John Fricke]

I deliver propane for a living. It has been my non-scientific observation that regardless of manufacturing claims.....it costs more to heat water fast than to keep it warm in a well insulated tank.

My .02 //9which is rapidly deflating in value.)

[Shawn Pixley]

Everyone in the house has to agree to the maximum Hot water temp. If not you go to lowest and some are unsatisfied.

[Von Bickley]

I recently helped my son replace his water heater. The old water heater probably could have been repaired but it was 25 years old so we decided to replace it. We replaced a 40 gal low-boy with a 50 gal low-boy. The new water heater is a Whirlpool and we got it from Lowe's for about $280.00. I already had all the fittings we needed so we only had to pay for the heater.

The new one probably won't last 25 years...... :D

[Frank Hagan]

"endless hot water" is a marketing term. You have to find out how much hot water it will deliver per minute. In houses with a lot of demand, and long runs, it may not deliver enough hot water to satisfy the demand. Typically, they provide from 4.5 to 10 gallons per minute of hot water with a 35 degree rise in the temp of the water. That means if your ground water is at 60 degrees, then the heater can provide 4.5 gpm of water at 95 degrees for a typical 150,000 btu unit. The larger the unit, the more gpm you'll get, but most are limited to the 35 degree temp rise.

If you are unhappy with the wait time between opening the tap and getting hot water, a tankless unit will be much the same as a storage tank; it is not "instantaneous" (another marketing term they had to abandon). You still have to purge the line of the cold water between the faucet and the water heater. If this is a problem in your house, ask your brother about installing a recirculating line.

Rinnai has a pretty good FAQ covering the disadvantages of a tankless design at this link (http://www.rinnai.us/tankless-water-heaters/faq/#question-4). Read through the questions, especially if you are in an area where the ground water is cold (see #18). And if you have long runs, consider the "sandwich" problem the FAQ talks about (something that you don't get with a tank type water heater).

There are some energy tax credits available for installing the most efficient units; make sure that yours qualifies if you decide to go this route. The tax credits don't take your tax liability below zero, so if you earn less than $40,000 or so on your taxable income, they may not help you much (depending on other deductions).

Usually, they need a gas line larger than the typical 1/2" provided for the 50,000 btu tank type water heater. That can drive up the cost. The smallest Rinnai requires a 3/4" line. Some have economical plastic venting, while others require expensive stainless steel venting. Some of the venting systems get very expensive, so make sure you include that cost on any estimates.

I used to work for a company bought out by Bradford-White, one of the three tank-type water heater manufacturers in the US, and they distributed the Rinnai tankless heaters under their name. The products I was familiar with (combo boilers and water heaters) did have their share of issues, but most were due to improper installation, undersized gas lines, etc.

[Dennis McGarry]

I just replaced my buddy tank with a tankless whole house unit.

Pros:

Limitless hot water to all taps. No more cold when you flush or turn on a faucet, (should be noted that this can be accomplished with a tank as well)

Fairly quicker on-demand hot. depending on the lengths of runs from the unit.

COns:

Inital cost.

Now for the cost savings, yes they run more efficient, now if you plan on staying in the current location for another 15-20 years, then it is going to save a bunch in the long run.

If you plan on moving within that time frame, a new high efficiency unit might be better fit.

Over all he is quite pleased with it and his gas bill has dropped, simply because you are not having to heat and reheat the water in the tank as it sits.

[Phil Thien]

I will add that when I looked into them, some units seemed to require more gas pressure than my local utility could promise. I can't remember which brand, but one of them pretty much required all the pressure my local utility provided to my house, and didn't leave anything left for my furnace.

[Tom Godley]

If you do a search you will find a few threads on them.


You need to do a little homework on them -- They work well in the correct settings.