Hot Water Heater Question

[DeniseM]

We have noticed that once in awhile, our hot water isn't hot. I checked it with a candy thermometer, and it was under 95 degrees. Normally, it's nice and hot. DH though we might have sediment so he drained the hot water heater (15 years old) and there was no sediment.

So the other night the water wouldn't get hot in the shower, and I also noticed that the pressure was fluctuating. I asked DH why and he said the automatic sprinklers were on.

So I tested it, and I finally figured out that when the sprinklers are on - our hot water in the shower does not get over 95 degrees, no matter how long I run it. As soon as the sprinklers go off - the shower temp returns to normal.

How can the sprinklers impact the hot water temperature?

 

[T_R_Oglodyte]

We have noticed that once in awhile, our hot water isn't hot. I checked it with a candy thermometer, and it was under 95 degrees. Normally, it's nice and hot. DH though we might have sediment so he drained the hot water heater (15 years old) and there was no sediment.

So the other night the water wouldn't get hot in the shower, and I also noticed that the pressure was fluctuating. I asked DH why and he said the automatic sprinklers were on.

So I tested it, and I finally figured out that when the sprinklers are on - our hot water in the shower does not get over 95 degrees, no matter how long I run it. As soon as the sprinklers go off - the shower temp returns to normal.

How can the sprinklers impact the hot water temperature?

First thing that comes to my mind is that you might have a significant flow restriction in your hot water leg. With the sprinklers off the water pressure is sufficient to get a reasonable amount of flow in the hot water system. Turning on the sprinklers, however, reduces the overall water pressure in the plumbing system, and there is no longer enough water pressure to move usable quantities of hot water through whatever the restriction might be.

First make sure that all of your shut-off valves to the hot water heater are wide open. Knowing that you live in California, if you are served by well water there's also good chance that you might have some calcium carbonate deposits in your hot water plumbing that are causing flow restriction.

-----

Of coure, the other possibility is that the sprinkers have inadvertently been tapped into the hot water system. Have you compared the temperatures of the water from the sprinkler system and from a cold tap where you can be be sure that it is unmixed with hot water?

 

[Phydeaux]

Nothing constructive to add that Troglodyte didn't already mention, other than this: "You don't need a hot water heater. You need a cold water heater".
-George Carlin

 

[ronparise]

Nothing constructive to add that Troglodyte didn't already mention, other than this: "You don't need a hot water heater. You need a cold water heater".
-George Carlin

I wasnt quite quick enough with the joke...damn

For Denise...Is this a new problem? , or something thats been going on for a while

I can imagine a plumbing setup where the house water pressure would be less when the sprinklers come on, but not the temperature, unless there is a backflow created when the sprinklers come on....Is the sprinkler water warm??

 

[joe-holiday]

15 year old Water Heater

You need to change it. They are meant to last 10 years or so
Is this Gas or Electric?
Joe

 

[DeniseM]

It has been going on for some time, but I just figure out that it happens when the sprinklers come on. Usually, the sprinklers are on at a time when no one would shower, so it took me awhile to figure it out.

I will have to check the sprinkler temp, but I don't think so. It is probably a water pressure issue. Our water pressure goes down dramatically when the sprinklers come one. But that's an easy fix - I just won't shower then!

 

[pjrose]

What's funny in your case is that using the sprinklers makes the shower colder, when, assuming the sprinklers are using cold water, that should make the shower weaker but hotter!

We have terrible water pressure, barely 25PSI, and any water use in one place lowers the pressure anywhere else. Flushing the toilet when someone is in the shower is a definite no-no - first it gets too hot so the person showering turns the heat down, then once the toilet finishes filling it gets cold again.

Just in the last week our water company has put in new piping down our street and each house has a pressure regulator out front that could go as high as 75PSI. We're not about to try that on 40 year old pipes - I can just imagine all the pipes in our house blowing out - but once all the installation is done we'll go up about 5PSI at a time, try that for a week or so, then add a bit more.

 

[dioxide45]

Could it be a problem with the regulator in the shower?. Some shower faucets have a mechanism in them that if it detects a loss in pressure of either the cold or the hot water, it adjusts to compensate. This is so you don't detect a major difference in temperature when taking a shower if someone uses a faucet or flushes a toilet elsewhere in the home. Perhaps a new tub/shower faucet is in order. Or perhaps the old one could be taken apart and just needs cleaned?

I really don't know much about this and am more less thinking out loud, but something to consider.

 

[Passepartout]

The lower temp while the sprinklers run baffles me, too. Lower pressure is to be expected, but not lower temp. Methinks you might be in the market for a new cold water heater. Today's quick recovery heaters have hardly any drop in temp even with multiple people showering one after another.

I will make a small unspecified wager that one element in your water heater has gone away. Probable the bottom one. Sediment isn't the culprit.

Jim

 

[theo]

A recent personal hot water heater experience...

I have insufficient knowledge to offer any constructive input on Denise's particular situation, but will share a very recent hot water experience, fwiw...

On December 10, my 40 gallon electric water heater "blew out" quite suddenly and without any warning or prior signs of performance deterioration. Water flowed throughout my (unfinished, fortunately) basement, probably for several hours, while no one was at home before the situation was discovered. I am still dealing with the aftermath and incurred damage.

What's my point? This electric water heater was "top of the line, the best quality unit available" (made by GE, but I suppose it could happen with any manufacturer). It had a 12 year warranty. This complete failure occurred almost exactly 8 years after its' purchase and installation. That's a complete failure within just 67% of the warranty term!

Yes, a replacement water heater was provided to me under warranty. However, "free replacement" (not including a few hundred dollars in plumber's labor, btw) certainly didn't solve the discouraging effects of two inches of water spread and contained throughout 1,200 square feet of surface area, nor did it "undo" any of the extensive property damage incurred. I have (perhaps unwisely) a $1,000 deductible on my homeowner's insurance, but the sheer aggravation was (...and still is) certainly far greater than any "financial" loss.

The moral of the story? Not sure. Maybe "don't expect your water heater to last for its' warranty term".
I wish there was some mechanism available for water flow to just somehow be stopped "automatically" upon any such breach in the system / water pressure, but I am unaware of any such "magic bullet"...

 

[JeffW]

...I wish there was some mechanism available for water flow to just somehow be stopped "automatically" upon any such breach in the system / water pressure, but I am unaware of any such "magic bullet"...

There is absolutely an item. Home shows (This Old House, Hometime) have shown them for years. If I remember correctly, a new electronically controlled valve is placed in the cold water inlet line. There is then a water sensor that goes near the water heater (obviously located where it detects a real leak, vs occasional moisture). When the sensor senses water, it turns off the valve.

I think I also remember seeing a sensor they mounted in bathroom, and demonstrated how an overfilling bathtub would also turn off the water. In this case, I think it would have been a remote sensor, and possible a shutoff valve installed just past the water meter (ie. whole house shutoff).

Lastly, there are similiar products meant to detect when a washing machine hose ruptures.

Water heaters are fickle. The previous one in my house lasted almost 18 years (did eventually leak, while we were on vacation of course, but amazingly leaked almost 100% out the basement door of the house (no stepover lip). The current one, I think a Sears 8 yr one, was put in in 1996, so that's goi)ng on 16 yrs. The thermostat sticks a little, but other than that, seems fine. And one in my parents house, if it's one I helped my father put in, geez, that could be 2 decades or more.

I did a quick search, here's a sample shutoff system:
http://www.smarthome.com/7115H2C/Water-Heater-Leak-Detection-FS3-4C/p.aspx

Looks almost too system. If you wanted ultimate protection, I'd get an AC powered unit, connected to an inexpensive computer UPS (can be $30). That way, even if you lose AC power, the unit is still functional.

I think when I get my water heater replaced, I'll probably put one in. It's seemingly impossible to predict the life of one (mine got over 200% life, whereas theo got 67%), but at least with a unit like this, you know that if it dies in 1 year or 20, there should be virtually no damage resulting from it.

Jeff

 

[SmithOp]

Sediment needs to be flushed regularly or it calcifies and wont flush out. My vote is for replacing the heater and have the plumber show your husband how to flush the new one on a regular schedule.

 

[UWSurfer]

First thing that comes to my mind is that you might have a significant flow restriction in your hot water leg. With the sprinklers off the water pressure is sufficient to get a reasonable amount of flow in the hot water system. Turning on the sprinklers, however, reduces the overall water pressure in the plumbing system, and there is no longer enough water pressure to move usable quantities of hot water through whatever the restriction might be.

First make sure that all of your shut-off valves to the hot water heater are wide open. Knowing that you live in California, if you are served by well water there's also good chance that you might have some calcium carbonate deposits in your hot water plumbing that are causing flow restriction.

-----

Of coure, the other possibility is that the sprinkers have inadvertently been tapped into the hot water system. Have you compared the temperatures of the water from the sprinkler system and from a cold tap where you can be be sure that it is unmixed with hot water?

Reinforcing what TR said, think of your plumbing water pressure as a replacement system. That is, if you don't have high enough pressure feeding the house, everything doesn't flow well. What you describe with the sprinklers happened to us before we re-piped our last house. The pipes were so corroded upon inspection after removal it was amazing any water moved through the house.

One you have water flowing (ie: sprinklers) the entire pressure to the system drops below what can flow into the water heater, reducing the amount of water coming from it and mixing with whatever is coming out of the shower.

Lots of good ideas in this thread but at the end of the day it comes down to not having enough pressure and locating the restriction cause.

 

[easyrider]

Could it be a problem with the regulator in the shower?. Some shower faucets have a mechanism in them that if it detects a loss in pressure of either the cold or the hot water, it adjusts to compensate. This is so you don't detect a major difference in temperature when taking a shower if someone uses a faucet or flushes a toilet elsewhere in the home. Perhaps a new tub/shower faucet is in order. Or perhaps the old one could be taken apart and just needs cleaned?

I really don't know much about this and am more less thinking out loud, but something to consider.

This is very likely the problem. We have had issues with temperture controll type fawcets in bathrooms with low water presure. If the bathroom sink fawcet gets hot but the bath tub fawcet doesn't, then it is the temp comtrol in the fawcet acting up.

 

[Passepartout]

Yes, a replacement water heater was provided to me under warranty. However, "free replacement" (not including a few hundred dollars in plumber's labor, btw) certainly didn't solve the discouraging effects of two inches of water spread and contained throughout 1,200 square feet of surface area, nor did it "undo" any of the extensive property damage incurred. I have (perhaps unwisely) a $1,000 deductible on my homeowner's insurance, but the sheer aggravation was (...and still is) certainly far greater than any "financial" loss.

The moral of the story? Not sure. Maybe "don't expect your water heater to last for its' warranty term".
I wish there was some mechanism available for water flow to just somehow be stopped "automatically" upon any such breach in the system / water pressure, but I am unaware of any such "magic bullet"...

Theo, I have no desire to hijack Denise's thread, but barring placing your water heater in a pan that will hold much of the contents and a sump pump to remove the water to a convenient drain there isn't much protection that I know of.

It wouldn't have helped while you were away, but alarms are available. Low cost ($10) battery powered units can be bought at home centers. I have them near my water heater (it leaked 3 or so years ago flooding the finished basement), behind the washer and refrigerator, and under the dishwasher. They use 9v batteries and I've found that really good lithium batteries last over 2 years. I check/test them when I do the time change/smoke detector battery drill twice a year.

$50 worth of water alarms/batteries have already saved me thou$and$ and the homeowners insurance carrier 10's of thou$and$ when my dishwasher failed. My insurance carrier said he was gonna buy a pallet of water alarms to give to policyholders. Haven't seen any yet.

I recommend these to everyone.

There are many available. Here's one: http://www.amazon.com/Zircon-Leak-Alert-Electronic-Batteries/dp/B002Q8GRPG/ref=pd_bxgy_hi_img_b

Jim

 

[JeffW]

...Lots of good ideas in this thread but at the end of the day it comes down to not having enough pressure and locating the restriction cause.

Below is a sample screw on water pressure gauge:

http://www.sears.com/shc/s/p_10153_...19x00001a&ci_src=14110944&ci_sku=SPM655456401

There's probably only a few places you can connect this: outside, utility room, maybe garage (not sure of spigot on water heater can hold the pressure). If these are in geographically different parts of the house, measuring the pressure with an without the sprinkler on, and comparing the numbers, might produce a finding (if there's no loss of pressure at one point in the house, and a big loss elsewhere, that would mean something).

Another test: how's the hot water say if instead of the sprinkler being on, you open the cold water in your utility tub, and let that run for just as long?

Jeff

 

[pjrose]

There is absolutely an item. Home shows (This Old House, Hometime) have shown them for years. If I remember correctly, a new electronically controlled valve is placed in the cold water inlet line. There is then a water sensor that goes near the water heater (obviously located where it detects a real leak, vs occasional moisture). When the sensor senses water, it turns off the valve.

. . .

The water-leak detector-shutuff sounds intriguing - but even if the water to the HW heater is shut off upon leak detection, wouldn't the HW heater still empty its 50 +/- gallons?

 

[T_R_Oglodyte]

Reinforcing what TR said, think of your plumbing water pressure as a replacement system. That is, if you don't have high enough pressure feeding the house, everything doesn't flow well. What you describe with the sprinklers happened to us before we re-piped our last house. The pipes were so corroded upon inspection after removal it was amazing any water moved through the house. ...

Precisely.

Another way to look at it.

Let's say that you are drawing 1 gpm for the shower and the shower temp that you want uses 0.75 gpm hot water and 0.25 gpm cold water.

Now let's consider the effects of a flow restriction in the hot water system. With higher system pressure, you can get more water across that flow restriction than you can at lower pressure. Some conditions might be that with full water pressure you can move 1 gpm through the hot water system, but with the sprinklers on the lack of pressure reduces that to 0.25 gpm.

Meanwhile since the cold water system is relatively unrestricted, the max flow rates of that system are much less affected by sprinkler system - instead of being able to 10 gpm of cold water at full pressure with the sprinklers on you can only get 5 gpm.

So with sprinklers off:
... desired = 0.75 gpm hot and 0.25 gpm cold
... available = 1 gpm hot and 10 gpm cold
... obtained = 0.75 gpm hot and 0.25 gpm cold
... result = Ahhhhhhhhh

And with sprinklers on:
... desired = 0.75 gpm hot and 0.25 gpm cold
... available = 0.25 gpm hot and 5 gpm cold
... obtained = 0.25 gpm hot and 0.75 gpm cold
... result = Brrrrrrrrrr

 

[T_R_Oglodyte]

The water-leak detector-shutuff sounds intriguing - but even if the water to the HW heater is shut off upon leak detection, wouldn't the HW heater still empty its 50 +/- gallons?

Maybe, maybe not.

With the water supply shut off, as the leakage occurs the pressure in the tank will decrease as water leaves the tank to the point that the tank is no longer pressurized. At the least the drip rate will diminish and it's likely that the leak will simply close if there is no pressure forcing it open.

If the leak is at the top of the tank (e.g., corrosion around the pressure relief valve is a common leak issue on hot water tanks), after the water level in the tank drops a bit the leak will stop.

If the leak is further down the side of the tank and it doesn't close up as pressure goes down, as water continues to drain from the tank with the inlet closed a vacuum will develop inside the tank. In most cases that will make the leak so slow that it can easily be responded to without major damage. A reasonably sized pan under the hot water heater (which would also contain the alarm set to detect water presence in the pain) would probably serve as adequate containment to provide time to respond.

******

But if the inlet to the tank isn't cutoff entirely (e.g, if there is sediment or scale on the shutoff valve seat) then the leak will probably continue unabated.

 

[DeniseM]

Sediment needs to be flushed regularly or it calcifies and wont flush out. My vote is for replacing the heater and have the plumber show your husband how to flush the new one on a regular schedule.

From my first post-

DH though we might have sediment so he drained the hot water heater (15 years old) and there was no sediment.

 

[DeniseM]

I just got spam via email from China with an Ad for a new water heater!
:rofl:

 

[pjrose]

I just got spam via email from China with an Ad for a new water heater!
:rofl:

Google knows all....is your email gmail?

 

[DeniseM]

Google knows all....is your email gmail?

Yep!.......

 

[JeffW]

I just got spam via email from China with an Ad for a new water heater!
:rofl:

Shipping might be a b____!!