Varied temps from gas WH

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Old 01-05-14, 08:55 PM
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Varied temps from gas WH

My gas WH -- GE 83gal SG50T12AA01 [probably @ 15+ yrs old] -- mostly works well but, will deliver over/under -heated water maybe a couple of times a year for a few days at a time. It has done this for about 5 years and not sure if I should start being concerned about replacing it.

Replacing it will open up a whole new set of inquiries.

edit: the WH says 83 gal on label but, the model number indicates a 50 gal [to me] and I do not see any other units that large. I only have two bathrooms [and two people] so I am guessing if a replacement is needed I could go considerably smaller if there is ample reason to do so.
 
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Old 01-06-14, 12:10 AM
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At fifteen years old that water heater is definitely on borrowed time, so is mine at almost 14 years. Definitely you should be anticipating a replacement heater sooner rather than later.

The thermostat in a gas-fired water heater has a tendency to "take a set" after operating at the same temperature for a number of years and if this happens it will not be as responsive as it was when new. Sometimes you can overcome this to a small degree by moving the thermostat dial a little bit one way or the other from where it has been. This will, of course, change the temperature of the stored water so be careful for a few days. While you could change out the thermostatic gas valve in a heater this old it is really throwing good money after bad.

I rather doubt it is more than 50 gallon capacity as larger gas-fired water heaters are usually considered commercial application rather than residential. Do you have any large soaking or whirlpool tubs that you use on a regular basis? How often do you wash dishes, do laundry and take a shower or bath in quick succession? If the answers are no then you could probably get away with a 40 gallon heater but if any answer is yes then I would stay with a 50 gallon model. If you are served by Seattle City Light then an electric heater may be worth considering.
 
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Old 01-06-14, 03:20 PM
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Thanks for the response Furd. Fifteen years was a guess because we bought the place about 9 years ago [time flies] already installed and the yellow energy sticker on the side references 1994 -- so I guess we have been very fortunate to have no serious problems [and with mixed reviews on GE WH's].

Actually served by PSE and it is 50 gal [says: Capacity 83 gal 'first hour rating' -- not sure what that means].

No excessive water needs -- so would smaller tank use less energy [i.e be more efficient] or are there 'economies of scale' with keeping a bigger unit? Possibly move to a tankless [which the wife is pushing for]?

It seems to be in surprisingly good condition for being 'old' but, I guess looks can be deceiving. So I guess my next step is start sorting through various makes/models to stay ahead.

Thanks
 
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Old 01-06-14, 03:30 PM
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First hour rating is including recovery time. Basically in one hour from a hot tank you can get 83 gal total with normal usage before it would have to completely re-heat a tank.

With a serial number we could look up the exact age....but yeah, that's old...esp for an electric. My gas AO Smith is still good...coming up on 24 years. Of course...now that I said that....
 
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Old 01-07-14, 01:19 AM
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Gunguy explained the first hour rating but he is in error about electric water heaters having a shorter life than gas-fired units. The "average" life of a gas-fired water heater is about eight years vs. an electric at about ten years. What "average" means in this circumstance is that half of the water heaters will experience a failure before that time span and half will experience a failure after that time span. I know of one electric water heater that has been operating continuously since before 1973. My own gas-fired unit has been operating continuously since February of 1999.

Permits ARE required for water heater replacements and if your jurisdiction is one connected to https://mybuildingpermit.com/default.aspx you can probably apply for, and receive the permit on-line. The tip sheet for water heater installations is here, scroll down to the 2009 Construction Tip Sheets and it is item 07. https://mybuildingpermit.com/Pages/c...ip-sheets.aspx (pdf)

Being served by PSE there is no advantage to going with an electric water heater. PSE has an increasing rate tiered rate structure so the more electricity you use the higher the unit cost.

I am not a plumber but like many plumbers I do not recommend instantaneous (tankless) water heaters. Their cost is two to three times the cost of a tank-type and the initial installation costs are generally high because they almost always require a new (larger) gas pipe all the way to the meter AND an expensive stainless steel venting system. The chimney vent normally cannot be used but the new vent run through the side wall. For this reason a tankless is almost always mounted on an outside wall to reduce the amount of venting material. There are some "high efficiency" condensing models that use PVC piping for the vent but they cost in excess of $2,000 and the "listed" efficiency only comes about when the heater is firing constantly. There are many other downsides to the instantaneous heaters as well.

Bottom line is that in most residential applications the instantaneous heater will save absolute zero dollars when capital and operating costs are combined and will probably have a negative return on capital when the increased maintenance required is calculated. Even with the increased combustion efficiency of the instantaneous heater the total cost would be enough to buy and install three tank-type heaters before ever achieving a ROI on the instantaneous heater.

A smaller tank-type heater MAY save you a few dollars in operating costs IF you get one with the upgraded insulation and a taller model. For my money the best deal is a six-year guarantee with the additional insulation if it is available. If the added insulation is not available then a water heater blanket will pay for itself in a couple of years. For the minimal gain in operating costs from going to a smaller tank capacity I would rather have the overload capacity of the larger heater with either (or both) the increased insulation or a blanket.

Longer guarantees are nothing more than the manufacturer betting that the heater will last longer than the guarantee and the extra cost is the insurance premium that you pay for this. ALL water heater tanks are the same and the ONLY differences between models is the added insulation, perhaps a second anode rod (or maybe a larger single anode), a brass drain valve instead of plastic and the addition of a "self-cleaning" curved dip tube. Every tank-type water heater installed should have the original drain valve and nipple removed and replaced with a brass or bronze nipple and brass ball valve with a garden hose adapter and cap. The curved dip tube can also be installed for about $20 or so.

Routine maintenance will significantly prolong the life of the heater. Simply flushing the tank periodically to remove sediment can do wonders. This flushing schedule is dependent upon the quality of the water. If your water utility is using surface water from mountain snow-melt then once a year is probably enough but if you have a deep well with high mineral content you will have to flush more often. Pull and inspect the anode rod every few years, probably after two years initially and then either shorten or lengthen the interval based upon the condition of the anode. When the anode has deteriorated to about one-third its original size replace it.

If you have any more questions, just ask.
 
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Old 01-07-14, 04:37 AM
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Nice write up Joel.....
 
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Old 01-07-14, 08:21 PM
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Nice write up Joel.....
Indeed -- Thanks for the information.

Did not realize I needed a permit to replace. Thanks for that because I am in Renton city limits.

Good news about the tankless because I really don't want one and, the only excuse I have come up with so far is: If we lose power, we don't have hot water.

The maintenance is what I have recently figured out -- unfortunately the first seven years I didn't do any because I didn't realize how easy it is and that it was necessary [thank you, YouTube]. On the positive side, I haven't seen any deposits the two times I have tested but, I have not checked the anode yet and it sounds like those don't typically last more than a few years before they should be replaced. This model says 'self-cleaning' so hopefully that has helped.

The information about the warranties will come in handy, too -- I would have been looking for the longer periods. Will get the blanket as an addition.

How easy is is to swap out the drain plugs and nipples [as you mentioned]? Is that two different items?
 
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Old 01-08-14, 12:49 AM
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I'm not sure about plumbing but ten years ago (my last experience) the Renton electrical inspector was a no-nonsense "book" man. I know it is a pain in the butt to get the permit but if I were in Renton I definitely would do so. As described on the tip sheet you will need to use flexible connectors for both water lines and the gas line along with two seismic restraint straps.

Replacing the drain valve is fairly easy but you need at least a 14 inch pipe wrench, an 18 might make it easier. If the new heater has the "in-line" type of drain valve that looks like a big piece of round plastic with a garden hose thread on the outer edge then just twist it off counter-clockwise and after several turns keep twisting with a pulling motion to get it out, it will take quite a few twists and a hard pull. Then the nipple can be removed with the pipe wrench. If you have the more conventional angled valve (could be brass, pot metal or plastic) then it just unscrews like any other pipe fittings.

Go to McLendon's for the new ball valve (3/4 inch size), 6 inch long brass nipple and the garden hose adapter and cap. Also pick up a small tube of Teflon pipe joint compound or else Rectorseal #5, either is good. If you are really out of your element the people who work for McLendon's are VERY knowledgeable. Tell them what you are doing and they will fix you up. Get the new flexible lines for the gas and water while you are there or if you want to save a couple of bucks you can get them from Lowes. Also the seismic restraint kit. You CAN get it all at Lowes but the knowledge of the McLendon's people more than make up for their slightly higher prices. Hopefully I won't get in any trouble naming store names but I feel very strongly about this.

[ATTACH=CONFIG]24435[/ATTACH]
Really cheap drain valve. (Image courtesy of Washington Water Heaters dot com)

Here is a really good site on water heaters.

Hot water heater troubleshooting | Rotten-egg solutions
 
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