Cannot get hot water in new home without Circulation Pump being On

[jcrum]

We have a Grundfos Type UP15-29SUC-TLC, Part #5889-6777 w/ check valve installed in our new home. However, if we turn this unit off and flush out all hot water lines and hot water heater, wait for water heater to heat up again, we can only get hot water in laundry room and master bath shower, only warm water in master bath sinks, tub, kitchen sink, and spare bath shower, and sink.

Is this right, that if they circulate your water lines for this pump that you have to it basically on all the time if you want hot water throughout home all the time????

[tinknocker service tech]

call your plumber and have him check your fixtures

[Coolmaniac]

Unless its a instant hot ( or whatever it's called) setup, seen a couple before. The hot water is piped in a loop with the fixtures branched off, the circ pump keeps water moving around the loop and back to the heater. So within a second or two of opening you've got hot water coming out of the faucet. It's the only reason I can think of to have a pump in a residential domestic water system unless the pressures really bad.

[Coolmaniac]

Unless its a instant hot ( or whatever it's called) setup, seen a couple before. The hot water is piped in a loop with the fixtures branched off, the circ pump keeps water moving around the loop and back to the heater. So within a second or two of opening you've got hot water coming out of the faucet. It's the only reason I can think of to have a pump in a residential domestic water system unless the pressures really bad. You could put in a time clock, set for when you tend to use hot water, if this is what you have.

[Coolmaniac]

I think somebodies servers wiggin out.

[jcrum]

The plumber has changed all filters in faucets and even replaced the grundfos hot water circulating pump. However, if we turn it off, we do not have hot water throughout house.

It does have a timer, but if you set it right for Monday thru Friday, it changes on weekends. Only if you leave it on 100% of time, do I have hot water all the time.

My concern, what if this thing breaks or they decide not to use them anymore, does this mean my home will not have hot water!! What kind of deal is that?

[tinknocker service tech]

The plumber has changed all filters in faucets and even replaced the grundfos hot water circulating pump. However, if we turn it off, we do not have hot water throughout house.

It does have a timer, but if you set it right for Monday thru Friday, it changes on weekends. Only if you leave it on 100% of time, do I have hot water all the time.

My concern, what if this thing breaks or they decide not to use them anymore, does this mean my home will not have hot water!! What kind of deal is that?


it is a recirc line and the pump is designed to run continously
there should be a thermastat on the line to turn the pump on and off by water temp.

you even without the pump should still be getting hot water it just takes longer and if the pipe runs are extremely long the water heater may not have enough capacity to handle it runs

your plumber should be able to solve this very easly but it may cost

the timer isnt needed

[karsthuntr]

The plumber has changed all filters in faucets and even replaced the grundfos hot water circulating pump. However, if we turn it off, we do not have hot water throughout house.

It does have a timer, but if you set it right for Monday thru Friday, it changes on weekends. Only if you leave it on 100% of time, do I have hot water all the time.

My concern, what if this thing breaks or they decide not to use them anymore, does this mean my home will not have hot water!! What kind of deal is that?
if it breaks you replace it. Grundfos has been around a long time, even if they did go belly up you have some other manufactures that make a replacement.

[mechanicalgsxr]

if it works while its running why would you turn it off ...look at the top of the water heater and see if the pipe nipples have arrows...

[Coolmaniac]

I'm not a plumber, so I'm likely wrong, but why would you use a thermostatic control on something that's supposed to stay the same temp? And I might worry about wear from starting and stopping if it was a 25+ HP motor. Grasslin makes some really nice time clocks that every day can be set for multiple on-off periods. Why have it running while you're sleeping, or if everyone's gone at the same time daily?
Here's the timer, simple, rugged, what I'd put if it was mine.

http://www.intermatic.com/Default.asp?action=subcat&sid=408&cid=121&did=44

[jcrum]

if it breaks you replace it. Grundfos has been around a long time, even if they did go belly up you have some other manufactures that make a replacement.

Did they go belly up? Well, the recirc pump works, it just that if it is off, then we have no hot water at all in kitchen sink and spare bath.

[jcrum]

if it works while its running why would you turn it off ...look at the top of the water heater and see if the pipe nipples have arrows...

Here again we were running 24/7 however, when we received a high electric bill, we thought maybe this is the problem, due to the fact I have read the water heater is pretty much running all the time to heat up the recirculating water, which is expensive to run.

In addition, I was wondering why do I need this thing, so what I have to wait a little bit on hot water, but I guess I don't have that option, if it's off, no hot water. Go figure

[mechanicalgsxr]

Here again we were running 24/7 however, when we received a high electric bill, we thought maybe this is the problem, due to the fact I have read the water heater is pretty much running all the time to heat up the recirculating water, which is expensive to run.

In addition, I was wondering why do I need this thing, so what I have to wait a little bit on hot water, but I guess I don't have that option, if it's off, no hot water. Go figure

did you check the pipe nipples coming out of your water heater

[jcrum]

if it works while its running why would you turn it off ...look at the top of the water heater and see if the pipe nipples have arrows...

See above as to why we turned it off. Why am I looking for pipe nipples with arrows??

[mechanicalgsxr]

See above as to why we turned it off. Why am I looking for pipe nipples with arrows??

some water heaters come with heat trap nipples and i have seen them installed backwards before...im just tryin to help brother


which line is the pump tied into? if they did it the way we do boilers and the check valve failed you could just be mixing cold water when the pump is off you would probably be better off having a mechanical guy look at this problem than a plumber...and that pump does not draw enough amps to be the cause of your high electric bill

[jcrum]

some water heaters come with heat trap nipples and i have seen them installed backwards before...im just tryin to help brother


which line is the pump tied into? if they did it the way we do boilers and the check valve failed you could just be mixing cold water when the pump is off you would probably be better off having a mechanical guy look at this problem than a plumber...and that pump does not draw enough amps to be the cause of your high electric bill

No arrows on the nipples. The pump has its own line. We thought the same thing about the pump not pulling many amps, however, we have read its not the pump amps, but if the pump is on always then the water heater is running all the time and it definitely can pull some amps, don't you think? Also, we did elevated the water heater to 140, which may have done it. We have now turned it back down to 120.

Any thoughts appreciated?

[mechanicalgsxr]

the pump has to tie on to something to circulate... the best thing you can do is look up a contractor in your area that does a/c heating and plumbing so you can get a tech that is experienced with plumbing systems as well as mechanical

dunno how big your house is or the layout sometimes the distance/pipe size dont allow the city pressure to push the water throughout your system so you would need the pump to help circulation...if the pump was on when you moved in it was probably there for a reason

just curious are your other fixtures mixing valve type or do they each have individual handles/knobs for hot cold

[jcrum]

the pump has to tie on to something to circulate... the best thing you can do is look up a contractor in your area that does a/c heating and plumbing so you can get a tech that is experienced with plumbing systems as well as mechanical

dunno how big your house is or the layout sometimes the distance/pipe size dont allow the city pressure to push the water throughout your system so you would need the pump to help circulation...if the pump was on when you moved in it was probably there for a reason

just curious are your other fixtures mixing valve type or do they each have individual handles/knobs for hot cold

The pump has its own supply line from the water heater, which circulates and goes back into the water heater. House is 2800 sq ft living and we are septic.

The house was just built so there was a pump on the system and after several meets with plumber, he changed out the pump and put this pump on the system. However, he could not necessarily tell us why we could not get hot water without the pump. He basically said, well, just leave it on. Well, this is a new home construction, I would just like to know that it was done properly.

[Ladiesman271]

The pump has its own supply line from the water heater, which circulates and goes back into the water heater. House is 2800 sq ft living and we are septic.

The house was just built so there was a pump on the system and after several meets with plumber, he changed out the pump and put this pump on the system. However, he could not necessarily tell us why we could not get hot water without the pump. He basically said, well, just leave it on. Well, this is a new home construction, I would just like to know that it was done properly.



The pump should use a recirc return line starting from the farthest hot water run. When you recirculate the hot water, the hot water from the tank goes through all the hot water pipes as usual and returns to the cold side of the water heater via that recirculate line / pump. If the pump check valve is leaking and the pump is off, then cold water will backfeed into the "hot" water side via the recirc line and the water will not be hot on those long runs (AKA where the recirc line ties in).

Is there a shutoff valve for that recirc line? If so, temporarily turn off the pump and shutoff the valve and give it a try.

[Ladiesman271]

No arrows on the nipples. The pump has its own line. We thought the same thing about the pump not pulling many amps, however, we have read its not the pump amps, but if the pump is on always then the water heater is running all the time and it definitely can pull some amps, don't you think? Also, we did elevated the water heater to 140, which may have done it. We have now turned it back down to 120.

Any thoughts appreciated?



http://www.builditsolar.com/Projects/Conservation/Recirc/RecircEnergy.htm

[freddy-b]

Do you have a well or city?

Water takes the POLR just like electricity, Sounds like without the pump the loop simply bypasses the water heater. You have a balancing problem perhaps ..you need a balancing valve?, a valve opened or closed that should not be?, or its piped wrong?.

[Sonicview]

If it is new construction the house should have a warranty for this... I would call the builder or the plumber who installed the system...

[larobj63]

If the pump check valve is leaking and the pump is off, then cold water will backfeed into the "hot" water side via the recirc line and the water will not be hot on those long runs (AKA where the recirc line ties in).

Bingo. When the pump is off, the cold water goes right through the recirc line to the far out fixtures, if there is a failed check valve or no check valve. Remember, the ricirc line is essentially a tie-in to the cold line if there is no check valve. It's likely the path of least resistance (especially if the recirc line is 1/2" or 3/4" pipe), so the fixtures in question see a mix of hot/cold (commonly know as "warm" :D) water.

HOWEVER -

The OP said he ran the water heater at 140 for a while. Which begs the question: Is there a mixing valve in the system??

If there is a mixing valve in the system, it is VERY easy to screw up a recirc system install, because it is much more complicated to do. You need a few checks, balance valves, and the recirc line has to split after the pump.

Either way - this should be pretty straightforward for a plumber to daignose if said plumber knew his or her stuff. ;)

[jcrum]

Bingo. When the pump is off, the cold water goes right through the recirc line to the far out fixtures, if there is a failed check valve or no check valve. Remember, the ricirc line is essentially a tie-in to the cold line if there is no check valve. It's likely the path of least resistance (especially if the recirc line is 1/2" or 3/4" pipe), so the fixtures in question see a mix of hot/cold (commonly know as "warm" :D) water.

HOWEVER -

The OP said he ran the water heater at 140 for a while. Which begs the question: Is there a mixing valve in the system??

If there is a mixing valve in the system, it is VERY easy to screw up a recirc system install, because it is much more complicated to do. You need a few checks, balance valves, and the recirc line has to split after the pump.

Either way - this should be pretty straightforward for a plumber to daignose if said plumber knew his or her stuff. ;)

Since we turned the water heater back down to 120, it seemed Ok for a couple of days, however, it did not seem as hot, and then today I took a little longer shower and ran out of hot water even with the recirc pump on. Something is wrong, we just do not know what. I am questioning whether something may be amiss with the hot water heater itself??

Any advice would be greatly appreciated.

[jcrum]

Since we turned the water heater back down to 120, it seemed Ok for a couple of days, however, it did not seem as hot, and then today I took a little longer shower and ran out of hot water even with the recirc pump on. Something is wrong, we just do not know what. I am questioning whether something may be amiss with the hot water heater itself??

Any advice would be greatly appreciated.

[tinknocker service tech]

everything you just discribed sounds like the diptube may have fallin

should have the unit checked by someone that understands recirc and long runs

[DanW13]

It's pretty hard for a Dip tube to have fallen off this is purely a mechanical problem and has nothing to do with a dip tube. Have you or the plumber checked the pump itself to see that it is in fact installed for proper water flow direction, there's arrows on the pump itself which shows the direction for flow of water, it could be that when he replaced the pump it was put in backwards. Another problem could be the temperature sensor setting is too low and the pump is turning itself off too soon or there is something lodged in the line somewhere to is blocking the water flow on the hot water side. Whatever it is I am sure it is something simple and is merely being overlooked.

[jcrum]

There is no temperature sensor on the recirc pump. It's either on or off.

There is only 1 arrow on the pump body and it is pointed to the line that goes into the water heater. The actual pump is installed upside down, should the output of the pump be going to the water heater or to the house.

[skippedover]

I don't know where you're located but in our state (MA) we're required to install a recirculating line w/pump from the farthest fixture when the distance from the water heater to any fixture is greater than 100-feet. If a recirculating line w.pump is required, it must also have a temperature sensor to turn the recirc pump off to prevent overheating of the line should the water heater thermostat fail.

The pump should be installed with the arrow on the pump pointing back toward the water heater. The pump/recirc line has no capacity to make any hot water. It only circulates hot water out of the water heater, through the hot water main lines and through the branch line to the farthest fixture, thence back to the cold water inlet side of the water heater. There should be a check valve in the return line (the linen going back to the water heater) to prevent cold water from flowing up the recirc return line and then out the hot water faucet at the fixture. It's the actual temperature of the water in the pipe that determines the temperature of the water coming out of the faucet, not the color of the sticker on the faucet valve nor the location of the faucet valve, left or right of the spigot. I do not know of a Grundfoss pump that has a check valve built in that seats tightly enough to stop reverse flow. They do make circulators with flowchecks in them but those are not going to stop the type of pressure that a domestic water line is under when a faucet is opened and the differential pressure is 50-70 psi. Whenever we put in a recirc line, we install a bronze check valve external to the pump to prevent reverse flow. If your system doesn't have an external check valve, I'd start right there with the troubleshooting. It's easy enough to troublshoot. Turn on a hot water faucet and then go to the basement, start at the water heater, find the hot water line and feel the line. It should be hot. Trace along that pipe and at every branch line, feel the pipe again on both sides of the tee. If it's hot approaching the tee and then the branch line is cold and the line on the other side of the tee is cold, then either the water is backfeeding through the faucet attached to that tee or the water is backfeeding from the other side of the tee. Follow the hot and cold and you'll generally find the problem in short order.

[flange]

Those systems use a temperature activated valve, typically located at the furthest faucet from the water heater. The purpose is to dump a little bit of warm water into the cold water supply line, therebt giving you instant hot water at any faucet. The theory is that you save a lot of water by doing that especially if you have long runs and dont use a lot of hot water. There is a chance that the valve is bad, or the check valve is installed backwords. The timer should be on the pump itself and be able to be set on/off like any normal timeclock. There should also be an on/off switch for the pump itself. The reality is that in many cases, the water savings will more than offset any gain in water heater usage. We have installed many of these in light commercial applications.

[larobj63]

Sorry to be a downer here, but I'm pretty convinsed all of this conversation is over the OP's head.

There are many on this board capable of diagnosing what's wrong, but we need a good accurate schematic of the layout, at a minimum.

Like I said before - if there is a mixing valve in the system, there is a lot of scope for the system to have been set up incorrectly to begin with.

If there is no mixing valve, the set-up is straight forward, and many of the suggestions given in this thread should be checked out, but by who?

He needs's a good plumber to look at it. :cool:

[jcrum]

During all of these problems and checking and re-checking, we started not to have hot water even with our circulating pump. Plumber returned and replaced both elements in the hot water heater last Thursday.

However, still to no avail.

Thermostat on water heater is set 125 degrees. With the circulating pump off, we checked temperatures at all faucets and shower heads the hottest was the laundry room at 108 degrees and the coldest was the master shower, tub, and spare shower were at 99 degrees.

I then checked the draining on the hot water heater and the water draining out is cool. Is it supposed to be hot?

The only think they have not changed out is the thermostat on the water and the actual water heater itself.

Also, if we turn the hot water supply valve off, we do not get any water thru any of the hot water spickets which suggest that we do not have a leaking of cold water into the hot water in the lines.

I am working on attaching several pictures to show the set up that we have. As soon as I get them uploaded, I will post. Maybe the plumber hooked it up wrong to begin with. Any advice would be greatly appreciated.

http://photo.livevideo.com/photo/water-heater-1_6E4194E1DE654912A058A23A6E8F8EE4.aspx

http://photo.livevideo.com/photo/water-heater-2_B594B35EB211483DB1CC7E066DE25ADF.aspx

http://photo.livevideo.com/photo/water-heater-3_9999C6D01F874E059B28552AFF9CA89E.aspx

http://photo.livevideo.com/photo/pump1_B1D97C923DF14DE8A4A6A5B7F3F8D33F.aspx

http://photo.livevideo.com/photo/pump-2_F7104938108048098C9C0DBDC784B27E.aspx

http://photo.livevideo.com/photo/pump-2_D24311DC0D65473C8AE95E60127DB732.aspx

http://photo.livevideo.com/photo/pump-5_1EC2F58E5BDB4CF4846890786970534A.aspx

[DanW13]

Other than the Hot water line going out from the tank, which one of the other 2 lines is the cold inlet to the tank ?

[Ladiesman271]

During all of these problems and checking and re-checking, we started not to have hot water even with our circulating pump. Plumber returned and replaced both elements in the hot water heater last Thursday.

However, still to no avail.

Thermostat on water heater is set 125 degrees. With the circulating pump off, we checked temperatures at all faucets and shower heads the hottest was the laundry room at 108 degrees and the coldest was the master shower, tub, and spare shower were at 99 degrees.

I then checked the draining on the hot water heater and the water draining out is cool. Is it supposed to be hot?

The only think they have not changed out is the thermostat on the water and the actual water heater itself.




Turn up the thermostat to 150, wait a few hours for temperature to move up, and retest those temperatures. Maybe the marked 125 thermostat setting is not 125 in reality!