Hot Water Coming Out Cold Water Throughout House??

[aumfc]

My kitchen faucet turns on with a sensor and is touchless:

https://www.amazon.com/Kohler-K-29709-VS-Artifacts-Kitchen-Stainless/dp/B07TSZM5KZ?th=1

My bonus room (above the garage) faucet turns on with a touch:

Single Handle Pull-Down Bar/Prep Faucet with Touch2O Technology in Chrome 9990T-DST | Delta Faucet

The powerful features of the Broderick™ Collection take center stage in the kitchen, with an industrial style that alludes to a rich heritage. The...

www.deltafaucet.com

The plumbers have spent hours going through all the lines and don't see any issues in the attic.

The problem with getting new plumbers is that these are the plumbers that built the house for the builder. I've already paid them and prefer not to pay someone else.

I don't think they've looked at the faucets. I'll run the test Bannerman suggested.

 

[aumfc]

A check valve will be need on the Cold inlet connection of each touchless faucet.

To easily verify hot water is flowing in reverse into the cold supply lines through the touchless faucets, while the recirculation pump continues to be active, feel the temperature of the cold supply line to each touchless faucet after no water has been drawn from that faucet for some time (ie: > 30-minutes). When no cold water has been drawn for 30-minutes or longer, the cold water line will usually have warmed up close to room temperature, but hot water passing through the faucet into the cold line, will cause the cold supply line to be hot, virtually equal to the temperature of the hot supply line.

I felt under the kitchen sink and both the incoming hot and cold water lines are hot. I closed the cold water valve to the kitchen faucet. I'll check their temps again in 30 minutes.

Am I correct in thinking that if the cold line drops in temp then the faucet is the problem? Or is there something else I would need to check?

 

[Sponsor]

 

[John Gayewski]

You need to have them come back and put check valves on the supply stops under the sinks.

 

[aumfc]

You need to have them come back and put check valves on the supply stops under the sinks.

Just the two electric sinks, right? The touch and the touchless?

 

[John Gayewski]

Just the two electric sinks, right? The touch and the touchless?

As long as you don't have any other crossover potential. I doubt your have crossover valves under any sinks becuse you have a dedicated recirc line. If they put crossover valves under some sinks and you have a recirc line they might think about getting rid of them.

It's kind of hard for me to picture a system that was purposely put in like this since it's so far from something I would do.

I'm not sure what constitutes a plumber in Alabama, but buying an expansion tool for pex isn't a qualification to be a plumber. Hopefully they learn a lesson that costs them some money and maybe they will do some research on hot water systems.

 

[aumfc]

I felt under the kitchen sink and both the incoming hot and cold water lines are hot. I closed the cold water valve to the kitchen faucet. I'll check their temps again in 30 minutes.

Am I correct in thinking that if the cold line drops in temp then the faucet is the problem? Or is there something else I would need to check?

Went back and both lines are room temp. Not sure what that means.

 

[John Gayewski]

Went back and both lines are room temp. Not sure what that means.

That means the water is no longer flowing through the faucet becuse you closed the pathway that the hot water was taking (the cold should never have gotten hot becuse you have a recirc line) . The hot won't get hot all the way up to the faucet becuse there's no flow there. Your recirc line should be hotter than it was before. That's why I wanted to know the temps.

A recirc line that is not hot, but warm means there's cold water getting mixed in somewhere.

 

[aumfc]

That means the water is no longer flowing through the faucet becuse you closed the pathway that the hot water was taking (the cold should never have gotten hot becuse you have a recirc line) . The hot won't get hot all the way up to the faucet becuse there's no flow there. Your recirc line should be hotter than it was before. That's why I wanted to know the temps.

A recirc line that is not hot, but warm means there's cold water getting mixed in somewhere.

Does that mean the faucet was the problem, or is it not enough information?

 

[Bannerman]

Went back and both lines are room temp. Not sure what that means.

You have already found the source of hot to cold crossover, but as an additional verification, reopen the under sink stop valves that you previously closed, then without running any water through those faucets, check the temperature of the hot and cold supply lines after 30-minutes.

I anticipate both supply lines will become hot again, so this will further confirm hot water is constantly passing through the electronically controlled faucets, and the hot water is pushing cold water backwards within the cold supply lines as an additional circulation return path back to the WH. A simple check valve installed on each electronic faucet cold water connection, will prevent reverse flow into the cold water supply from those faucets.

As stated previously by others, the placement of the circulation pump is incorrect, which is largely contributing to why this situation has occured. In my view, this makes it evident your plumber does not possess the required knowledge or experience to correctly design and configure hot water recirculation systems. This view is further enforced by an inability to diagnose and correct the resulting problem.

 

[aumfc]

You have already found the source of hot to cold crossover, but as an additional verification, reopen the under sink stop valves that you previously closed, then without running any water through those faucets, check the temperature of the hot and cold supply lines after 30-minutes.

I anticipate both supply lines will become hot again, so this will further confirm hot water is constantly passing through the electronically controlled faucets, and the hot water is pushing cold water backwards within the cold supply lines as an additional circulation return path back to the WH. A simple check valve installed on each electronic faucet cold water connection, will prevent reverse flow into the cold water supply from those faucets.

As stated previously by others, the placement of the circulation pump is incorrect, which is largely contributing to why this situation has occured. In my view, this makes it evident your plumber does not possess the required knowledge or experience to correctly design and configure hot water recirculation systems. This view is further enforced by an inability to diagnose and correct the resulting problem.

Reopened the hot water valve. Ran no water anywhere in the house. 1 hour later, both hot and cold supply lines are still room temp.

Wouldn't the water in the hot water line cool down but stay in the line since it'd have nowhere to flow to? Same with the water in the cold line?

 

[John Gayewski]

Reopened the hot water valve. Ran no water anywhere in the house. 1 hour later, both hot and cold supply lines are still room temp.

Wouldn't the water in the hot water line cool down but stay in the line since it'd have nowhere to flow to? Same with the water in the cold line?

Both were open for 30 minutes along with the pump? The pump would have to be running and both valves would have to be open for flow to happen.

 

[John Gayewski]

Also you need to be checking both faucets. If you shut one off the other could start circulating.

Here's a better test. Shut the cold water supply off under both sinks. Or the hot or both it doesn't matter. Then let the pump run. Then take a shower. If you have hot water the problem is found.

 

[WorthFlorida]

my post #2 and #7 was my number one though. Touchless faucets are the suspects. At the at parts diagram shows nothing about any check valves. I'm not sure where the solenoid sits.

https://media.deltafaucet.com/PartsDiagram/DPD-K-9990-DST.pdf

 

[aumfc]

UPDATE:

I shut off the cold water supply to both electronic faucets on Wednesday. No water has been used in the house in the last 3 hours (since 830am). Just now (1130am) I go to the kitchen sink, which is touchless and has had the hot water shut off for over 48 hours, and I get hot water when I turn it on. After 10 seconds or so it goes to cold.

So, if hot water supply to both of the electronic faucets is off, and I'm still getting hot out of the cold side, that means it's not the faucets right? What else could it be and what other tests can I try?

Thanks.

 

[Bannerman]

I shut off the cold water supply to both electronic faucets on Wednesday

the kitchen sink, which is touchless and has had the hot water shut off for over 48 hours, and I get hot water when I turn it on. After 10 seconds or so it goes to cold.

Which was shut off, the hot or the cold supply stop? Your statements contradict each other.

Was the hot water circulation pump continuing to run the entire time?

 

[WorthFlorida]

It's has sure turned into a head scratcher. It has happened and post on this form, the fill tube on the cold side has broken allowing cold water to immediately be taken in the hot side. If I remember somewhere it was said you don't have the problem when the pump is running.

As Bgard in his post suggests the tanks should be in parallel, not in series. I see the set up is all wrong. There is no way to bypass one tank for the other. In parallel you can have both elements burning for hot water. The current set up the right tank will do most of the water heating, the left tank becomes a storage tank.

Read this manual, you might pick up on some thing. It's a better solution for recirculating systems, only runs via temperature.

https://manuals.totalhomesupply.com/wp-content/uploads/manuals/AMH2K-7-Instruction-Sheet-1.pdf

This must be a beautiful home at 6000 sq feet. All in hind site a better way would be one 50 tank with a thermal mixing valve such as a Cash Acme mixing valve. Set the water heater at 140 degrees and the mixing valve would bring the water down to 120 degrees. it be equivalent to a 90-100 gallon tank. For the far end bathroom, there many large point of use water heaters that would be installed perhaps in a bathroom closet. There would be almost immediate hot water.

It's not always possible to find answers without seeing the installation itself. I may be time to call on another plumber that knows recirculate systems.

 

[Jeff H Young]

If you closed angle stops at 2 faucets I think its safe to say if problem continues it is not caused by those 2 faucets.
Maybe try the test again at kitchen sink but with supplys disconected and running into a bucket and not actually using the kitchen faucet on your testing . this is getting long and confusing at least for me but maybe others are still remembering all the details. I thought there might be bridge valves involved as well ? make note in your comment when doing a test on the state of the pump on and running etc. maybe check to se if the return is warm as well

 

[Bannerman]

I thought there might be bridge valves involved as well ?

The OP said nothing about bridge valves - that was suggested by a later commenter.

It's still not clear if both the hot and cold stops were reopened directly before 10 seconds of hot water flow. With only 10 seconds of hot water, that suggests the source of crossover continues to be that electronically controlled valve, particularly if the supply stop valve had been opened for a short time before the faucet was activated.

Perhaps one or the other (?) stop valve under the sink, is not fully stopping flow while closed, which your advice to disconnect both supply lines should quickly identify.

At this point, we don't know the brand model for each electronically controlled faucet. I am assuming there is only 1 electronically controlled solenoid that is controlling mixed flow to the faucet spout, thereby leaving both the hot and cold inlets open to act as a crossover between the hot to cold supply.

We also don't know if the mixed temperature is pre-set internally so users cannot adjust the water temperature as desired, or if there is a control to allow each user to modify the spout temperature. If there is a user control, the test result will be highly variable, as for instance, the control for one test could be positioned for 50/50 equal incoming hot and cold flow, but set to allow only 100% incoming hot water flow during the 2nd test.

 

[John Gayewski]

Are both water heaters hot? Feel the outgoing pipe on the left side of each one and see if they are both hot.

 

[aumfc]

The OP said nothing about bridge valves - that was suggested by a later commenter.

It's still not clear if both the hot and cold stops were reopened directly before 10 seconds of hot water flow. With only 10 seconds of hot water, that suggests the source of crossover continues to be that electronically controlled valve, particularly if the supply stop valve had been opened for a short time before the faucet was activated.

Perhaps one or the other (?) stop valve under the sink, is not fully stopping flow while closed, which your advice to disconnect both supply lines should quickly identify.

At this point, we don't know the brand model for each electronically controlled faucet. I am assuming there is only 1 electronically controlled solenoid that is controlling mixed flow to the faucet spout, thereby leaving both the hot and cold inlets open to act as a crossover between the hot to cold supply.

We also don't know if the mixed temperature is pre-set internally so users cannot adjust the water temperature as desired, or if there is a control to allow each user to modify the spout temperature. If there is a user control, the test result will be highly variable, as for instance, the control for one test could be positioned for 50/50 equal incoming hot and cold flow, but set to allow only 100% incoming hot water flow during the 2nd test.

Sorry for the typo before. I cut off the hot water supply to both electronic faucets. The links to both of these are included in a previous post.

I used the kitchen sink frequently the last couple of days while the hot water has been off.

The pump was running as it always does. It's scheduled to run from 5am to 2pm and from 5pm to 12am.

The water pipe is hot leading from one tank to the next.

Finding another plumber is not that easy. The first one on my job didn't work, this is the second. And it took weeks to get him. I've exhausted all avenues I have to find someone. My only option would be to call guys I find online. Unless anyone here can recommend someone near Birmingham, AL.