Hot Water Heater Info Request

[oldskool]

Anyone gone thru this recently? My 20+ year old Kenmore 75 gallon gas water heater is going haywire. Water gets cold, then extremely hot - likely a thermostat issue, but at 20+ years, hardly worth repairing, as it also has a small leak. Since it's located near lower level bedrooms, really don't want to press my luck any further and have flooding damage.

Have heard alot about the tankless type. Curious of anyones experience(s) with the same. 6 people in the home, lots of baths, showers, and laundry, 2 dishwashers.....high demand in peak periods so we need ample supply. Or should we just do another large tank type similar to current with a 75,000 btu burner.

Any advice for replacement would be appreciated.

 

[wayupnorth]

I dont believe a tankless would work for your situation. They work best with one faucet at a time but will quickly go cold with multiple ones open at once. I would go for a tank model with a large tank and quick recovery. Tankless models are very efficient but with 6 people and multiple people using hot water at once I believe you would be disappointed.

 

[oldskool]

Thanks

@wayupnorth - your response is appreciated. After talking with another person who stated about the same, I'm going shopping for another large tank.

 

[hydralique]

Another characteristic of a tankless heater is they need a larger gas supply pipe than most tank-type heaters since they have to put out so much heat instantly on demand. Depending on the house layout this might be a problem.

 

One heater that might suit your needs is a Polaris by American Water Heaters. It's a hybrid between a tankless and tank type. The burner and control system are similar to the tankless, being very high output, but there is a small tank that provides buffering to prevent the temperature fluctuations tankless units are prone to as demand changes. A Polaris 30 gallon probably puts out hot water like a conventional 100 gallon though you'd have to check for the exact equivalent.

 

[sudsmaster]

I agree a tank type would be best for your situation. Since your current one is having thermostat issues and is leaking, the sooner the better. There is a danger the thermostat could fault to always on, resulting in runaway heating and triggering the temp/pressure safety valve to release the extra pressure. And if the valve is clogged, the whole tank could explode.

 

[oldskool]

Much Thanks

@ hydralique, sudsmaster, and wayupnorth - Greatly appreciate everyone's advice and recommendations. I've contacted a plumber who will install a new one most likely tomorrow, pending availability of the replacement unit. It's an American Standard, 75 gallon, 75,000 btu which is equivalent of what we have now.

John

 

[whirlcool]

There is a danger the thermostat could fault to always on, resulting in runaway heating and triggering the temp/pressure safety valve to release the extra pressure. And if the valve is clogged, the whole tank could explode.

In the years before the safety valves were required it actually was quite common to have an exploding hot water tank. They'd come up from the basement and shoot through the upper two floors of a house and land a block or two away, usually on top of some poor innocent passerby. It made a lot of noise too. We always check our relief valve once every 6 months to make sure it still works.

 

[a440]

Check out Bradford White brand.
I have a 70 GAL Bradford White Power Vent.
It is so efficient! The PVC discharge air is so cool. It is using almost 98% of the burner heat for the water.
I drained it for the first time after 3 years of use and there was no sediment at all. I timed it from a full fill to heat the water to the setting. (I keep it set quite hot) It took 24 minutes to heat 70 Gallons. That is quite efficient.
You will pay a little more, but it is worth every penny. I have never run out of hot water, or even come close to it! I saw a huge difference in my gas bill the first month after I installed it.
Brent

 

[oldskool]

How

...does one check it?

Please advise.

Thanks
John

 

[washer111]

My Two Cents:

Unless you have fangled "intelligent" instantaneous units, it is practically pointless using them in high-demand.

Like others said, they tend to struggle once >1 tap is being used, and some models can't even deliver a straight temperature - You'll start off with a cold blast, then things heat up rapidly and reach a peak. Eventually, the system decides the water going out is "hot enough" and slows down the flame. On older units (especially) the time between shutting off and restarting is low enough to give you seriously HOT or COLD blasts in the shower/laundry etc, something that is undesirable.

As you've already made your decision, my point is moot, but make sure you get a system BIG enough to support your needs. For a family of your size, 80 or more gallons might make more sense, and give you extra hot water when you need it.
And make sure you get the high(est) efficiency model - if you use that much hot water you ought to be making the most efficient use of the heating source available. High Efficiency gas with PLENTY of insulation on the tank/pipes is paramount.
Another suggestion, if you live in a cold enough climate and have a boiler system, you could perhaps get an additional heating loop fitted from that to your water heater so as to increase efficiency in the winter months (depending on what fuel is used there). That way, you are heating for two with one to some degree and maximising savings - at least in theory.

 

[volvoguy87]

High Demand Tankless.

I must respectfully disagree.

My folks installed a high-capacity State brand tankless water heater about 3 years ago. They have a huge shower with multiple heads that could drain the old 50 gal. tank in one shower. Their tankless water heater has a condensing burner (PVC flue) and one of the highest galon-per-minute ratings available. At Thanksgiving, they typically have as many as 15 house guests, plus all the cooking and washing dishes and utensils that goes along with it. There is also lots of laundry (15 people use a LOT of towels!). Since the water heater was installed, there has never been a cold shower (or anything else for that matter).

With a tankless water heater, it doesn't matter how many people are in the building, what matters is the maximum number of gallons of hot water needed in any one-minute span. As long as your water flow doesn't exceed that rate, you'll never know you've got a tankless. If you need more flow, many tankless water heaters can be installed in series and wired together so they talk to each other so the burners modulate to keep the output temperature in check and even to alternate the units so their parts wear at the same rate.

Interesting stuff,
Dave

 

[whirlcool]

How

...does one check it?

The high pressure relief valves have a handle on them. Just open the handle and close it very rapidly. If you hear water coming out of the tubing that comes out of the heater via the valve, your valve is working.

Since our water heater is in the attic, the tubing leads to a vent in our soffit.

 

[DADoES]

 
Yes, there are misconceptions again being batted here around regards to tankless water heating.  There is truth that retrofitting it to a tank installation is not always reasonable.  In cases in which it is suitable, and new construction installs which are easier by design, the presumed usage issues that are often cited/warned are overblown.

 

[mattl]

The one main drawback for me with tankless is the amount of temp rise it can generate.  If that could be overcome I might be tempted to get one.  120 degree water does not cut it for me.

 

[labboy]

Bradford-White

We installed a Bradford-White at the recommendation of my brother who is a facility director at a national restaurant chain. They use B-W in almost all of their restaurants.

We have been extremely happy with it and saw our bill drop by over 60% after installation.

Bob

 

[turboace]

Again, the way you overcome the temperature rise, or delta T needed with an instant water heater is to have them in series. I'm in NC so my cold is never really cold, so I just have one Ranaii - it can deliver 12gpm of 140 F water as long as there is propane in my tank and water from the city. If you think of it, that's actually a lot. A shower uses 2.5 GPM, but with it set at 140F you blend in some cold so you aren't really using up 2.5 GPM of hot, maybe more like 2. That would be six showers at once. Love mine sice I travel so much, I know I'm not wasting energy heating water when I'm gone.

 

[oldskool]

@whirlcool

Thanks for the instructions.
Much appreciation.

John

 

[sudsmaster]

One caveat about testing the pressure relief valve... I've seen ones that are internally encrusted with scale fail to shut off completely after testing. So be prepared for that... with a bucker or whatever is needed to catch the drips. Worst case, be prepared to shut the water heater down and install a new valve. They are not expensive, usually under $20, although some may have tubing installed on their outlets to direct water to a safer area.

 

[eafomby]

water heater

Though this is an old thread but debate on tankless water heater is always a hot topic. Most of the water heater has an averae life span of 10 to 15 years and it seems that yours is up there in age. Thus I would recommend to have your plumber or water heater repairs NJ take a look at it and advise you on how much useful life it has left and on installing the best type of water heater for your house.
http://allweekplumbing.com/water-heater-repairs.html