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TheSMJ

join:2009-08-19
Farmington, MI

Replace TP valve or water heater?

Last week my dad and I (mostly my dad) re-plumbed my water heater so the water entered the tank through the drain outlet at the bottom because the dip tube was broken. Since this was done the hot water had been working great.

Fast forward to last night; I was about to leave the house and happened to go into the basement to put some clothes in the dryer, when I find the floor almost covered in water (floor drains are clogged, but that's another thread). I look at the water heater and I find the TP valve had opened, and it was dumping steaming water out pretty quickly. I turned off the water to the tank and started vacuuming out the water from the basement floor. Once I was finished with that (about 20-30 minutes later) I tried turning the heater back on - TP valve was still dumping water. Not having time to take care of it at the moment I left the house with the tank off and the thermostat turned all the way down.

Almost 3 hours later I tuned the tank on, and the TP valve stayed off. Since I was about to go to bed I turned the tank back off in case it the valve decided to open again while I slept.

Now, before I returned to the house that night I decided that I was going to replace the whole water heater rather than just the valve, but since the valve closed itself after the tank cooled down, I'm now wondering if it was doing it's job and there really was a pressure/temp issue. Of course, I feel like the only way to be sure would be to replace the valve (or drop $350 on a new tank), just to wait and see if it happens again.

I should mention that the water heater is 18 years old. It's not leaking, but the dip tube already broke and now this.

So, should I replace the whole water heater, just the TP valve, or turn it all back on when I'll be around for a few hours to babysit it and see what happens?



ropeguru
Premium
join:2001-01-25
Mechanicsville, VA

At 18 years old, should have just replaced the heater when you found the bad dip tube. You are living on borrwed time with the tank at this point. Buy a new heater and be done with it.



Lurch77
Premium
join:2001-11-22
Oconto, WI
kudos:4
reply to TheSMJ

I agree. Time to cut your losses and buy a new tank. You'll come out ahead. At its age, the problems you have now are just the start to the nickel and dime job it'll be giving you.



Hawk
Riding Thermals
Premium
join:2003-08-25
The Desert
reply to ropeguru

^^^ +1



tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
kudos:9
Reviews:
·G4 Communications
·Fairpoint Commun..
·Hollis Hosting
reply to TheSMJ

From your description it is impossible to know for sure if the problem was with the PTRV itself or over temp or over pressure. The fact the valve stopped leaking tends to indicate it is working correctly. However under normal circumstances the valve will only open for a little while to lower temperature or relieve pressure.

Make sure the temperature setting is not too high, or water pressure is high. Well pressure is typically in the 50-60psi range town water somewhat higher. Often times municipal systems will install a regulator at the meter to reduce pressure.

Given the age of the water heater I agree with the other posters time to replace it. If the system is on town water think about installing an expansion tank. That gives expanding water a place to go. Since water is nearly incompressible, but does expand with temperature, without a tank it does not take much increase in volume to produce a dramatic increase in pressure.

Since you have been able to practice on the old tank replacing it with a new one should be a piece of cake.

/tom



jjoshua
Premium
join:2001-06-01
Scotch Plains, NJ
kudos:3
reply to TheSMJ

If the tank is out of warranty then it's time to replace it.


boaterbob
Premium
join:2005-08-01
Moncks Corner, SC

I'd also consider having a water leak sensor (or 2 or 3

Home Depot has multiple type wireless sensors that can be used with a command module. The command module is about $29 at Home Depot (maybe less at Amazon, etc - but Home Depot makes returns easy) and then you can add multiple modules.

Here is the water leak module at Home Depot:
»tinyurl.com/aa4m6ns
About $15. The command module is shown on the same page.

Lowe's sells the same product but are a little higher in price.

There are standalone sensors, but I like the idea of adding multiple type sensors/alarms and controlling them with 1 command module.



Hall
Premium,MVM
join:2000-04-28
Germantown, OH
kudos:2
reply to jjoshua

said by jjoshua:

If the tank is out of warranty then it's time to replace it.

?? Are you serious ?

I just replaced our water heater. Previous owners had it installed in 1985. Sure, it may not have been the most efficient one out there (on the other hand, in the summer when the gas furnace isn't being used, I have no complaints about my gas bill, which is 100% from the WH). It did develop a leak, but it was more or less a "dribble". We didn't do anything about it for 3-4 days (waited until the weekend to have plenty of time to change it).

MaynardKrebs
Heave Steve, for the good of the country
Premium
join:2009-06-17
kudos:4
reply to TheSMJ

@ 18 years old, your tank is living on borrowed time. Most tanks need replacing by that amount of time -- unless they are stainless steel.

The T&P valve may have shut itself because of sludge being pumped up from the bottom of the tank rather than the valve working correctly.



jjoshua
Premium
join:2001-06-01
Scotch Plains, NJ
kudos:3
Reviews:
·Verizon FiOS
reply to Hall

said by Hall:

said by jjoshua:

If the tank is out of warranty then it's time to replace it.

?? Are you serious ?

Yes. HWH tanks are engineered to last the life of the warranty. Anything longer is borrowed time.

garys_2k
Premium
join:2004-05-07
Farmington, MI
Reviews:
·Callcentric
·callwithus

said by jjoshua:

said by Hall:

said by jjoshua:

If the tank is out of warranty then it's time to replace it.

?? Are you serious ?

Yes. HWH tanks are engineered to last the life of the warranty. Anything longer is borrowed time.

Unless you regularly replace the sacrificial anode rod, then they can last and last.

MaynardKrebs
Heave Steve, for the good of the country
Premium
join:2009-06-17
kudos:4

said by garys_2k:

Unless you regularly replace the sacrificial anode rod, then they can last and last.

Not necessarily.

The mode of failure for most vitreous (glass) lined tanks is that the glass develops microscopic cracks over time due to thermal shock effects. This tends to occur more with tanks that have a high 'dump' load (people to take baths vs. showers, big soaker tubs, etc....) where a large proportion of the tank contents is used in a short period of time. The large infux of cold supply water onto the hot glass is what causes the cracking.

Over time these cracks let water reach the mild steel tank substrate and that's where the corrosion begins. The principal difference in a tank with a 9-year vs. 12-year warranty is the thickness of the vitreous lining - it's a few mils thicker when you have a longer warranty.


Hall
Premium,MVM
join:2000-04-28
Germantown, OH
kudos:2
reply to jjoshua

said by jjoshua:

Yes. HWH tanks are engineered to last the life of the warranty. Anything longer is borrowed time.

I call bullsh*t on that. No one can design (predict) how long components can last accurately enough to do that. If they did design this way, plenty of water heaters will fail before the warranty is up and by plenty, I mean "too many" as far as the manufacturer is concerned. By the same token, many will last longer as well, but companies won't consider that a wash. Every one that fails under warranty is one too many.


jack b
Gone Fishing
Premium,MVM
join:2000-09-08
Cape Cod
kudos:1
reply to TheSMJ

T&P valves will only dribble on an over-pressure condition, just enough to to keep the tank pressure below the valve's rated setpoint. When water dumps out as you describe, it's usually because of high temperature.

I wouldn't waste the time to change the T&P, it might be the thermostat failing and the T&P was only doing it's job, fortunately, but only depending on how one views that.

Go for a new tank.
--
~Help Find a Cure for Cancer~
~Proud Member of Team Discovery ~



AVD
Respice, Adspice, Prospice
Premium
join:2003-02-06
Onion, NJ
kudos:1
reply to TheSMJ

I'd rather take a cold shower than be out of toilet paper, but that's just me. I guess if the water is hot, you can shower after every dump.
--
* seek help if having trouble coping
--Standard disclaimers apply.--



Faster
Premium
join:2013-03-09
reply to TheSMJ

Replacing the water heater is the only practical and reasonable solution given its age.


TheSMJ

join:2009-08-19
Farmington, MI
reply to boaterbob

said by boaterbob:

I'd also consider having a water leak sensor (or 2 or 3

Home Depot has multiple type wireless sensors that can be used with a command module. The command module is about $29 at Home Depot (maybe less at Amazon, etc - but Home Depot makes returns easy) and then you can add multiple modules.

Here is the water leak module at Home Depot:
»tinyurl.com/aa4m6ns
About $15. The command module is shown on the same page.

Lowe's sells the same product but are a little higher in price.

There are standalone sensors, but I like the idea of adding multiple type sensors/alarms and controlling them with 1 command module.

I already thought about getting one of these since the floor drains are FUBAR. Thing is, it would need some way of contacting me if I'm not home for it to be worthwhile (SMS, email, etc). I'm sure that's do-able with an off the shelf product, but I have yet to see one that wasn't also part of some larger security/home automation system.

Maybe I'll buy another Raspberry Pi for something like this. I'm sure it's been done before.

Anyways, I suppose you guys convinced me to just replace the heater. I'm was just going to get a $349 3-year warranty unit, and check\replace the anode rod every 2-3 years. I'll still plumb the incoming cold water in through the drain port to cut the dip tube out of the equation, and I'll crack the seal on the anode rod so it'll be easier to replace later on.


ropeguru
Premium
join:2001-01-25
Mechanicsville, VA

said by TheSMJ:

I'll still plumb the incoming cold water in through the drain port to cut the dip tube out of the equation

Why? THis just seems rediculous to me and cannot understand why one even consider this.


pike
Premium,MVM
join:2001-02-01
Washington, DC
kudos:3

said by ropeguru:

Why? THis just seems rediculous to me and cannot understand why one even consider this.

Agreed. OP's water heater was manufactured during the period (1995) when faulty dip tubes were rolling off the line. Not likely to experience this failure again.

TheSMJ

join:2009-08-19
Farmington, MI

I would agree that it's a waste of time under normal conditions, but since the current water heater is already set up this way, why not?



DKS
Damn Kidney Stones
Premium,ExMod 2002
join:2001-03-22
Owen Sound, ON
kudos:2
reply to Hall

said by Hall:

said by jjoshua:

If the tank is out of warranty then it's time to replace it.

?? Are you serious ?

I just replaced our water heater. Previous owners had it installed in 1985. Sure, it may not have been the most efficient one out there (on the other hand, in the summer when the gas furnace isn't being used, I have no complaints about my gas bill, which is 100% from the WH). It did develop a leak, but it was more or less a "dribble". We didn't do anything about it for 3-4 days (waited until the weekend to have plenty of time to change it).

Yes. The sweet spot with water heaters is 6 years. If it lasts more than that, it's good. But is is also due for replacement. Mine is a rental. The installers tell me that 10 years is average.
--
Need-based health care not greed-based health care.


rfhar
The World Sport, Played In Every Country
Premium
join:2001-03-26
Buicktown,Mi
Reviews:
·Power-Net Intern..

said by DKS:

said by Hall:

said by jjoshua:

If the tank is out of warranty then it's time to replace it.

?? Are you serious ?

I just replaced our water heater. Previous owners had it installed in 1985. Sure, it may not have been the most efficient one out there (on the other hand, in the summer when the gas furnace isn't being used, I have no complaints about my gas bill, which is 100% from the WH). It did develop a leak, but it was more or less a "dribble". We didn't do anything about it for 3-4 days (waited until the weekend to have plenty of time to change it).

Yes. The sweet spot with water heaters is 6 years. If it lasts more than that, it's good. But is is also due for replacement. Mine is a rental. The installers tell me that 10 years is average.

I have never had one last less than twenty years. Of course I let a pro tell me what to buy.
--
Whoever said that ignorance is bliss wasn't refering to a person with a computer at his fingertips!

Cure Disease with your computer


Cho Baka
Premium,MVM
join:2000-11-23
there
kudos:2
Reviews:
·TekSavvy DSL
·Cogeco Cable
reply to Hall

said by Hall:

[Every one that fails under warranty is one too many.

Especially when there may be liability for water leakage.
--
The talented hawk speaks French.


FiReSTaRT
Premium
join:2010-02-26
Canada
reply to TheSMJ

18 years? Time for a re&re lol



DKS
Damn Kidney Stones
Premium,ExMod 2002
join:2001-03-22
Owen Sound, ON
kudos:2
reply to rfhar

said by rfhar:

I have never had one last less than twenty years. Of course I let a pro tell me what to buy.

Lucky you.
--
Need-based health care not greed-based health care.


jack b
Gone Fishing
Premium,MVM
join:2000-09-08
Cape Cod
kudos:1
reply to Cho Baka

said by Cho Baka:

Especially when there may be liability for water leakage.

No tank manufacturer has any liability whatsoever for water damage from a leaker. They are only on the hook for the replacement tank, prorated in many cases, and not even the associated removal/installation labor cost.
--
~Help Find a Cure for Cancer~
~Proud Member of Team Discovery ~


Cho Baka
Premium,MVM
join:2000-11-23
there
kudos:2

I find that somewhat difficult to believe.

I would not be the least surprised to know that they disavow liability, I just can't see that they actually have none.
--
The talented hawk speaks French.



jack b
Gone Fishing
Premium,MVM
join:2000-09-08
Cape Cod
kudos:1

1 recommendation

The majority of manufacturers installation instructions include a standard disclaimer:

said by American Water Heater :

Under no circumstance will the manufacturer be held
liable for any water damage in connection with this
water heater.

They instruct to either install the heater in a pan piped to a drain, or where a leak will not cause property damage.

Kinda straightforward.
--
~Help Find a Cure for Cancer~
~Proud Member of Team Discovery ~


Hall
Premium,MVM
join:2000-04-28
Germantown, OH
kudos:2

Yeap, I remember reading wording along those lines just a few weeks ago when I installed ours.



mackey
Premium
join:2007-08-20
kudos:12

1 recommendation

reply to Hall

said by Hall:

said by jjoshua:

Yes. HWH tanks are engineered to last the life of the warranty. Anything longer is borrowed time.

I call bullsh*t on that. No one can design (predict) how long components can last accurately enough to do that. If they did design this way, plenty of water heaters will fail before the warranty is up and by plenty, I mean "too many" as far as the manufacturer is concerned. By the same token, many will last longer as well, but companies won't consider that a wash. Every one that fails under warranty is one too many.

Actually, in this day and age material science can tell you exactly how long it is likely to last. No matter how well they build it, there will always be defective units or units that fail earlier then expected. This is built into the cost of the product. When they engineer something to last just the length of the warranty they know a few will probably fail sooner; if the cost of replacing those units is less then how much they save by using thinner/cheaper materials then they have no problem with doing that.

/M