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Melissa2007B
02-12-2012, 10:28 PM
I mentioned this before. We have a modular house with a gas water heater that has stacking problems. The overflow temp pressure valve is working, in that it closes when the temp gets low enough, but when the water gets too hot and it opens, it creates like a stacking loop, where the burner runs more and it overheats the water and the valve stays open at a trickle, causing cold water to come in the bottom and keep the burner on, while the top is scalding hot. I wish they had water heaters with a circulating pump to avoid this problem and keep the water a uniform temp throughout the tank.

But I've turned this down to the lowest setting, to try to break the cycle and the water is still scalding and the valve is still trickling.

This is getting really frustrating, because the house is too humid from the hot water in that pan and it's causing condensation on my bathroom skylight and too much humidity in the house.

Runs with bison
02-13-2012, 12:22 AM
I mentioned this before. We have a modular house with a gas water heater that has stacking problems. The overflow temp pressure valve is working, in that it closes when the temp gets low enough, but when the water gets too hot and it opens, it creates like a stacking loop, where the burner runs more and it overheats the water and the valve stays open at a trickle, causing cold water to come in the bottom and keep the burner on, while the top is scalding hot. I wish they had water heaters with a circulating pump to avoid this problem and keep the water a uniform temp throughout the tank.

But I've turned this down to the lowest setting, to try to break the cycle and the water is still scalding and the valve is still trickling.

This is getting really frustrating, because the house is too humid from the hot water in that pan and it's causing condensation on my bathroom skylight and too much humidity in the house.

Wasn't the humidifier the source of the stacking problem? If so, have you turned down the humidifier settings?

Gary Swart
02-13-2012, 01:32 AM
It sounds to me like you need a thermal expansion tank. I suspect you have a pressure regulator valve that prevents the water expansion from being absorbed by the city water main. The creates too much pressure in the heater and causes the T/P valve to trip and relieve the excess pressure. (that's what it is supposed to do) Much has been written on this forum about expansion tanks and a little searching will find plenty of data.

hj
02-13-2012, 05:00 AM
1. The relief drain line is NOT supposed to empty into the pan.
2. If it were the temperature function opening it would open FULLY and not stop until the tank temperature had dropped. This would overflow the drain pan in a matter of seconds and flood the area.
3. Only the pressure side will "drip" and allow a small amount of water to exit, and that assumes that the pressure build up is such that a small amount of water will relieve it. Otherwise, it would also run until the pressure was reduced causing the same flooding.
4.You have misdiagnosed the problem and therefore are making the wrong corrections.

Hackney plumbing
02-13-2012, 05:27 AM
1. The relief drain line is NOT supposed to empty into the pan.
2. If it were the temperature function opening it would open FULLY and not stop until the tank temperature had dropped. This would overflow the drain pan in a matter of seconds and flood the area.
3. Only the pressure side will "drip" and allow a small amount of water to exit, and that assumes that the pressure build up is such that a small amount of water will relieve it. Otherwise, it would also run until the pressure was reduced causing the same flooding.
4.You have misdiagnosed the problem and therefore are making the wrong corrections.

Have you considered the relief valve may not be working properly? Just because its trickles water doesn't mean the tank is not getting too hot. The valves are by no means "perfect".

Sure it could be just pressure at first but then as cold water enters the tank it can cause the burner to fire and cause stacking.

She may be having several issues. She needs to call a professional.

ballvalve
02-13-2012, 11:02 AM
Its not "stacking" but a bad water heater that needs replacement, at least a bad thermostat.

Melissa2007B
02-13-2012, 11:47 AM
Wasn't the humidifier the source of the stacking problem? If so, have you turned down the humidifier settings?

It's been down, but I found out what the cause is, last night. I turned the water temp WAY down and the valve still trickles, even with water temp of 135, so the valve is bad. I gotta replace it. Thanks guys.

By the way, I need a big long handled plumber's wrench. Where's the best place to find a used one for less money? Like a pawn shop?

Update 4:39 PM: I stopped by a couple of pawn shops but they only carry bigger stuff like electric saws & sanders, not hand tools. So I went to Home Depot. They had a medium sized Husky pipe wrench, made in China, but lifetime warranty. Came to $16 with tax. Took it home ( I'm 7 minutes from there. ) and turned the water off, opened the tap for a few minutes, then unscrewed the old valve. It was hard to turn. Even with the weight of that heavy pipe wrench, I had to really lean on it, but eventually it loosened. So I unscrewed it until it was loose, then using a rag ( it was hot ) unscrewed it the rest of the way until it popped out...releasing a few gallons of scalding water down on my hand. !@$# Took the old valve & went back to Home Depot. They had two, one in a box for $8.97 and the other in a blister pack for $14 and change, but the guy tells me they're the same! I thank him, he walks away, and I compare numbers. Watts XL100, both of them! $5 more for the fancy blister pack. :D Am I moron? NO. I take the $8.98 one.

Take it home, teflon tape it, screw it in good and tight with the slip joint pliers and finally the pipe wrench, connect the vertical pipe to it, turn the water back on, I'm done. Total cost, about $26!

I would have GLADLY hired a plumber for $50, parts & labor, but they screw themselves out of work with the union thing. They woulda charged $75 just to tippy toe through the door, then another $75 an hour, one hour minimum, plus the part?

I ran cold mountain snow melt Denver tap water over my left index finger, it's fine thanks. :)

By the way, the water heater was built by Rheem and installed in this modular house that wasn't on the lot and occupied by us until Jan of 2005. How come the valve went bad that fast?

ballvalve
02-14-2012, 12:11 PM
You said earlier that at the lowest setting the water was still scalding.... sure you don't have a thermostat problem? What made the temp finally drop down?

Melissa2007B
02-14-2012, 05:00 PM
You said earlier that at the lowest setting the water was still scalding.... sure you don't have a thermostat problem? What made the temp finally drop down?

"Scalding" to me is "ouch". I think we can get scalded technically at only 117 degrees? :D

Hmm, it's apparently a function of time: http://www.mwke.com/personal-injury/Water-Scalding-Injuries

"The temperature for domestic hot tap water must not exceed 120 Fahrenheit, according to the International Plumbing Code, known as the IPC Standard. Most water heaters can push the temperature up to 140 degrees, but that will burn a user. ( My note: Yeah if they're dumb enough to hold something under it. ) :p

People might not expect to be at risk of injury from a tap, but a water heater malfunction may occur suddenly in a home or commercial system.
Lower Tap Temperatures to Prevent Water Scalding Injuries

The risk of water scalding injury rises significantly if the water temperature exceeds 120 degrees. It would take 8 minutes of exposure to water heated to 120 degrees to sustain second degree burns, and 10 minutes to sustain third-degree burns.

A water heater that has raised the temperature to 150 degrees can cause third degree burns in just one second. At 130 degrees, it would take about 30 seconds to sustain comparable injuries."

Gary Swart
02-14-2012, 05:16 PM
I glad you solved your problem, but before we leave this, I would like to point out a couple of things related to your comments about the high price of hiring a plumber. First, you are right, they are not cheap. But why should they be? They have equipment to buy and maintain, insurance to cover their business and employees, they are not paid if they are not on a job, going to and from the job takes time and gas, and finally, they certainly deserve to make a decent living. On the other hand, the reason many of us DIY is to spare this expense if it is a job within our abilities. Certainly changing a T/P valve is a task that almost anyone should be able to handle, but other tasks are not so simple. As you found out, even the simple task of changing out a T/P valve required you to buy a tool. So, try to see the other side of the cost of hiring a professional.

jimbo
02-14-2012, 05:24 PM
I would have GLADLY hired a plumber for $50, parts & labor,

So he has $10 wholesale price, plus cost of inventory, so the valve is worth $20 on his truck. And you very generously would give him $30 to schlepp out to your place, pay gas and insurance on his van, workers comp, and by the way BOTH sides of the 15% social security tax, and who knows what kind of business license tax the city has, plus what it cost him yearly to keep the plumbing license, and oh by the way...CE classes to keep the license...and etc!

Hackney plumbing
02-14-2012, 05:51 PM
It's been down, but I found out what the cause is, last night. I turned the water temp WAY down and the valve still trickles, even with water temp of 135, so the valve is bad. I gotta replace it. Thanks guys.

By the way, I need a big long handled plumber's wrench. Where's the best place to find a used one for less money? Like a pawn shop?

Update 4:39 PM: I stopped by a couple of pawn shops but they only carry bigger stuff like electric saws & sanders, not hand tools. So I went to Home Depot. They had a medium sized Husky pipe wrench, made in China, but lifetime warranty. Came to $16 with tax. Took it home ( I'm 7 minutes from there. ) and turned the water off, opened the tap for a few minutes, then unscrewed the old valve. It was hard to turn. Even with the weight of that heavy pipe wrench, I had to really lean on it, but eventually it loosened. So I unscrewed it until it was loose, then using a rag ( it was hot ) unscrewed it the rest of the way until it popped out...releasing a few gallons of scalding water down on my hand. !@$# Took the old valve & went back to Home Depot. They had two, one in a box for $8.97 and the other in a blister pack for $14 and change, but the guy tells me they're the same! I thank him, he walks away, and I compare numbers. Watts XL100, both of them! $5 more for the fancy blister pack. :D Am I moron? NO. I take the $8.98 one.

Take it home, teflon tape it, screw it in good and tight with the slip joint pliers and finally the pipe wrench, connect the vertical pipe to it, turn the water back on, I'm done. Total cost, about $26!

I would have GLADLY hired a plumber for $50, parts & labor, but they screw themselves out of work with the union thing. They woulda charged $75 just to tippy toe through the door, then another $75 an hour, one hour minimum, plus the part?

I ran cold mountain snow melt Denver tap water over my left index finger, it's fine thanks. :)

By the way, the water heater was built by Rheem and installed in this modular house that wasn't on the lot and occupied by us until Jan of 2005. How come the valve went bad that fast?

Modular home? You mean a trailer home? Does it have axles under it?

Melissa2007B
02-14-2012, 05:59 PM
I glad you solved your problem, but before we leave this, I would like to point out a couple of things related to your comments about the high price of hiring a plumber. First, you are right, they are not cheap. But why should they be? They have equipment to buy and maintain, insurance to cover their business and employees, they are not paid if they are not on a job, going to and from the job takes time and gas, and finally, they certainly deserve to make a decent living. On the other hand, the reason many of us DIY is to spare this expense if it is a job within our abilities. Certainly changing a T/P valve is a task that almost anyone should be able to handle, but other tasks are not so simple. As you found out, even the simple task of changing out a T/P valve required you to buy a tool. So, try to see the other side of the cost of hiring a professional.

Oh I agree with you Gary, especially since I'm a professional process server by trade and have roughly the same kinds of expenses. Sorry if I offended any pro plumbers, but you're right.

We see people try to do it themselves, to save a few bucks and royally screw things up. I've done nearly 10,000 serves since 2006 and know what I'm doing. Then we get calls from people who are shopping around for lowest price, not realizing that they're not buying a name brand TV set and that all of us aren't the same. AND Colorado isn't even regulated in the process serving industry, so there are perjurers and thieves out there as well.

I certainly appreciate someone who knows what they're doing, though I can't always afford them. ;)

Melissa2007B
02-14-2012, 06:01 PM
Modular home? You mean a trailer home? Does it have axles under it?

No, modular means one that's factory built and put on a foundation. Supposedly we saved money that way, but I'd never do it again.

Hackney plumbing
02-14-2012, 06:32 PM
No, modular means one that's factory built and put on a foundation. Supposedly we saved money that way, but I'd never do it again.

Thats good. Some people swear by the modular built. I think it comes down to quality control.

Dont be surprised if you have another problem with the relief valve. If you do the chances of the relief valve being the "real problem " are slim,its just doing its job. Your pressure may be high and that can cause the spring to get weak. A spring under tension holds a stem with a rubber washer against the relief valve seat to seal.

The spring is held in place with a metal insert that is pressed in place from the top of the valve. The temp probe is a plastic coated copper tube with a silicone rubber type material inside that surrounds a metal rod. When the temp goes up the rod expands and opens the valve.

I have found many new relief valves that would not open at 150 psi. One didn't open until over 250 psi.

Melissa2007B
02-14-2012, 06:38 PM
Thats good. Some people swear by the modular built. I think it comes down to quality control.

Dont be surprised if you have another problem with the relief valve. If you do the chances of the relief valve being the "real problem " are slim,its just doing its job. Your pressure may be high and that can cause the spring to get weak. A spring under tension holds a stem with a rubber washer against the relief valve seat to seal.

The spring is held in place with a metal insert that is pressed in place from the top of the valve. The temp probe is a plastic coated copper tube with a silicone rubber type material inside that surrounds a metal rod. When the temp goes up the rod expands and opens the valve.

I have found many new relief valves that would not open at 150 psi. One didn't open until over 250 psi.

I think we measured the PSI here at 90 PSI one summer. It may be because they have to pump the water uphill from the valley in Denver and we're at about 5470 feet here, along the way to others that are higher up on the west side suburbs.

Hackney plumbing
02-14-2012, 06:44 PM
I think we measured the PSI here at 90 PSI one summer. It may be because they have to pump the water uphill from the valley in Denver and we're at about 5470 feet here, along the way to others that are higher up on the west side suburbs.

Thats 10 psi too high based off your reading. The pressure may be higher than that during certain parts of the day and it can be lower. To solve this problem install a pressure reducing valve and thermal expansion control. All that together would cost you around 400.00 give or take a couple hundred. Thats not bad considering the costs of damage the high pressure can do to you piping,faucet,toilets,ice makers,dishwashers......basically it's not good for the system. Things will fail at a faster rate.

Plumber111
02-14-2012, 06:53 PM
"I would have GLADLY hired a plumber for $50, parts & labor."

Me too. Even non-union. But they don't exist. For some reason they need things like food and heat that seem to cost more than that.

That's why there aren't "$50.00 parts and labor" plumbers that last. Takes them a little while to figure it out.

hj
02-15-2012, 05:11 AM
quote; Just because its trickles water doesn't mean the tank is not getting too hot

If it trickles adn then stops, it is NOT because it is too hot, Once it starts "trickling" or running, because it is too hot it will NOT stop until the water cools down, which could not happen if the burner is coming on to create the "stacking" he is complaining about. When he removed the valve, I did not read anything about him having to remove a drain line from the valve. The valves are in a "hostile environment" and should be tested every MONTH to make sure they work. Many six year old safety valves will not work, but do not necessarily drip.

quote; "I would have GLADLY hired a plumber for $50, parts & labor."
I would not even have started my truck for that price. And it is NOT a "union thing", it is a "make a profit and not go broke" thing. If you find a GOOD $35.00 an hour plumber, send me his number and I will subccontract all my work to him and clear about $75.00 an hour for myself.

Hackney plumbing
02-15-2012, 05:17 AM
quote; Just because its trickles water doesn't mean the tank is not getting too hot

If it trickles adn then stops, it is NOT because it is too hot, Once it starts "trickling" or running, because it is too hot it will NOT stop until the water cools down, which could not happen if the burner is coming on to create the "stacking" he is complaining about. When he removed the valve, I did not read anything about him having to remove a drain line from the valve. The valves are in a "hostile environment" and should be tested every MONTH to make sure they work. Many six year old safety valves will not work, but do not necessarily drip.

Relief valves are not to be tested once a month.....that would be obcessive and compulsive disorder. All I know is the original poster needs to call a professional.....just like the instructions on the relief valve box says she needs to do.

Melissa2007B
02-15-2012, 12:00 PM
quote; Just because its trickles water doesn't mean the tank is not getting too hot

If it trickles adn then stops, it is NOT because it is too hot, Once it starts "trickling" or running, because it is too hot it will NOT stop until the water cools down, which could not happen if the burner is coming on to create the "stacking" he is complaining about.

I'm female dear. :D I actually turned the thermostat down until the water was eventually only 135 degrees, and it still dribbled. That was when I knew it was the valve.

Melissa2007B
02-15-2012, 12:01 PM
Relief valves are not to be tested once a month.....that would be obcessive and compulsive disorder. All I know is the original poster needs to call a professional.....just like the instructions on the relief valve box says she needs to do.


WHY? It's fixed now.

Runs with bison
02-15-2012, 01:10 PM
Labor rate often depends more on where you live. I've not found the quality of the work in any way correlates with the charge out rate (same for mechanics or dentists or doctors for that matter.) Some of it depends on what you are asking them to do and what they are good at.

I don't mind paying more for a good plumber. They come with the tools and materials they need, find solutions to problems, and do good installs. They have skills/pracitice and experience that I lack and that's why I call them.

Ironically most expensive ones I've dealt with arrived without the parts they needed...not sure why they even bother to bring the van since it doesn't have the most basic items in it. They could save a lot of money by riding a cheap scooter with a tool box strapped onto it. Forgive me if I get a bit irritated when I have to come up with a solution, the tools and parts during a job for something I'm paying someone else for their expertise and equipment to handle.

The cheapest I had were called out to clean out the drains and main sewer line. I had them snake everything including the vents. There were two of them and their rate worked out to about $20/hr each. That was just a few years ago in southwest Georgia. I have no idea how that made any economic sense, but their company had been doing business a long time. It seemed to cure the slow/stopped drain problems in that older home (where some of the old cast iron had already rusted out and been replaced.)

Hackney plumbing
02-15-2012, 02:00 PM
WHY? It's fixed now.

Good. I hope its "fixed". You know they can blow up......

liquidplumber
02-15-2012, 08:32 PM
T and P valves do go bad. It happens. That being said, the poster says she turned the heater "WAY down" to 135! and also that incoming pressure was 90 psi Im willing to consider that the T and P valve was actually doing its job and relieving a potentially dangerous over pressure condition. Several things to consider, you are definantly in need of a PRV to reduce that pressure. also a thermal expansion tank is in order. More importantly, dont ignore that bleeding T and P valve, your gas valve/thermostat may be sticking and over heating the water, that happens too.

As for the guy who suggested opening the T and P valve every month, all your doing is asking the seal to get a peice of trash stuck in it and causing it to leak. Leave it alone, youre not helping anything and youre only going to create a problem.

Im not even gonna go into all the taxes fees and expensive regulations I have to comply with that cost me thousands and thousands of dollars a year. Why just TODAY i shucked out $432 for one state fee, one bond payment, and one of my multiple insurance payments. Once upon a time I had my operating costs figured out to the penny. at that time EVERY TRUCK I had running had to make $100 every hour just to BREAK EVEN. Thats no profit, no advertisement. So, when I charge $158 plus $20 ($178 total) for the T and P valve you can see what a monsterous profit Im making for the hour ive spent diagnosing the issue, determining the solution, and fixing the problem. The "big profit" Ive made also is severely diminished if I had to drive 30 minutes to get to you and 30 minutes to the next call. I know it seems like the plumbers are making a killing, but trust me, you wouldnt want to have our monthy operating bills, taxes, fees and required regulatory cost burdens..... You probably wouldnt want to have our phones either at 9pm almost every night, midnight several times a week, saturday evening, sunday afternoons... etc etc. :p

jadnashua
02-15-2012, 09:42 PM
It's very rare (from my limited experience and physics background) to get stacking problems on a WH. This is a theoretical problem that is more often a problem with diversely different densities like in salt water and fresh water, not all water from the same source. Not saying it couldn't happen, but it is not common - convection generally wins, preventing it. A gas WH heats from the bottom and middle. An electric reverts to the bottom when the top's heating element has been satisfied.

They have used this effect to store heated water in places like Isreal with fresh/salt water, and it can happen naturally (think thermoclines in the ocean), but not so much in a small scale thing like a WH.

Hackney plumbing
02-15-2012, 10:32 PM
It's very rare (from my limited experience and physics background) to get stacking problems on a WH. This is a theoretical problem that is more often a problem with diversely different densities like in salt water and fresh water, not all water from the same source. Not saying it couldn't happen, but it is not common - convection generally wins, preventing it. A gas WH heats from the bottom and middle. An electric reverts to the bottom when the top's heating element has been satisfied.

They have used this effect to store heated water in places like Isreal with fresh/salt water, and it can happen naturally (think thermoclines in the ocean), but not so much in a small scale thing like a WH.

Stacking is not as common now because the manufacturers shortened the dip tubes. 20 years ago they were longer.

Runs with bison
02-15-2012, 10:54 PM
I agree with jadnashua, this is unlikely.

While the T&P is the device that was apparently failing, others are likely to be correct that the actual root cause is thermal expansion and/or excessive supply pressure. Get a~$10 gauge that will display peak pressures and rig it up indoors with it being winter and all (probably off the water heater drain.) Then, when the pressure exceeds about 80 psig plan on installing a thermal expansion tank and PRV.

When having the original install done by a plumber, select components that you can replace or rebuild without calling a plumber. (No offense to professionals, but simple wrench job replacements are DIY.) PRV's and thermal expansion tanks have finite lifetimes. Watts PRV's are a sore point for me since I know how to read a graph, pressure, and flow. There is no way in Hades that the one's I've had are getting anywhere near their published design curve after the first few months of operation. Several plumbers have told me that the springs are the weak component, but they are difficult to rebuild...although when I replace the next one I'm going to orient it so that the top works is vertical and away from the wall, so that it can be reassembled easily in place. (From examining the one I replaced there is nothing wrong with the valve/seat, etc. No build up or erosion.) What happens is that as they fail the pressure might be set to 65-75 psig, and fall off by 10-15 psi with even a low flow.

ballvalve
02-16-2012, 11:09 AM
Im not even gonna go into all the taxes fees and expensive regulations I have to comply with that cost me thousands and thousands of dollars a year. Why just TODAY i shucked out $432 for one state fee, one bond payment, and one of my multiple insurance payments. Once upon a time I had my operating costs figured out to the penny. at that time EVERY TRUCK I had running had to make $100 every hour just to BREAK EVEN. Thats no profit, no advertisement. So, when I charge $158 plus $20 ($178 total) for the T and P valve you can see what a monsterous profit Im making for the hour ive spent

A good mechanic in a BAD market really must come up with some sort of sliding scale. I just could not give grandma on Social - non-security a 200$ bill for an 8$ valve and sleep at night. Make up for granny at the McMansion where the doctor [who is in a trade where you still get paid for killing your patients] and his wife, the stockbroker-bloodsucker got her 800,000$ bonus for screwing the public out of a few billion that year.

Most of you guys have to have the shiny new truck with 1000$ worth of tires on them. My plumbing van is a 600$ auction item, maybe a 1985, that was the sheriff search and rescue van. Holds a good 5 grand worth of parts. If you really think someone cares about the truck you drive, you got a bone in your head. I'll take the guy with his bumber wired on, and red duct tape on the taillights.

To give you a taste of the economy, an auction here last week sold a huge fleet of ford f350 vans, 2000 year up to 2007. With internal racks and cages, maintenance records, etc. - smogged and ready to go for $1800 to 4500 bucks. All from a few busted plumbers and electricians that thought appearance would always carry them through.

Looks like granny got herself a harbor fright wrench, and the retired handyman at the church to help her out. total cost: 2 cups of coffee or a beer and 15$ in parts.

Bid on a local job here. My price was half of 2006 costing, to keep the guys alive, burn dead inventory. The owner got about 7 bids - like a pack of sharks descending on fresh meat. I guess the guy that got it has no employees, probably no insurance, thus, and drives a ford escort.

Runs with bison
02-16-2012, 06:44 PM
Most of you guys have to have the shiny new truck with 1000$ worth of tires on them. My plumbing van is a 600$ auction item, maybe a 1985, that was the sheriff search and rescue van. Holds a good 5 grand worth of parts. If you really think someone cares about the truck you drive, you got a bone in your head. I'll take the guy with his bumber wired on, and red duct tape on the taillights.

To give you a taste of the economy, an auction here last week sold a huge fleet of ford f350 vans, 2000 year up to 2007. With internal racks and cages, maintenance records, etc. - smogged and ready to go for $1800 to 4500 bucks. All from a few busted plumbers and electricians that thought appearance would always carry them through.

I didn't want to poke the other guy in the eye over it, but I'm with you on this. I don't really care what the guys are driving as long as it gets them to the job and carries the parts they need for the job. (I do understand that they need something that won't leak oil/tranny fluid on the customer's drive though.)

If the trucks are too nice, I figure I'm paying for that. It's the same way I feel about banks...if the interior is too opulent then I avoid them.

I would think a T&P changeout if called to do it, would get the standard minimum charge for the truck coming out (~$75 here) plus the part since it is a quick job.