Hot water out of cold taps - plumber is stumped

[hj]

1. quote; Have seen this before where it backfeeds through the washing machine solenoid.

IMPOSSIBLE. the hot and cold waters have individual valves and they empty directly into the washer. There is NO way for them to be interconnected. In addition, they would both have to be stuck in the open position for it to happen if it were possible, in which case the washing machine would be overflowing.

2. If the pump is on the hot discharge from the heater, then you probably have a retrofit circulation system, and there is a "4 port manifold" under one or more sinks which has to be replaced.

 

[Bustergordon]

1. quote; Have seen this before where it backfeeds through the washing machine solenoid.

IMPOSSIBLE. the hot and cold waters have individual valves and they empty directly into the washer. There is NO way for them to be interconnected. In addition, they would both have to be stuck in the open position for it to happen if it were possible, in which case the washing machine would be overflowing.

2. If the pump is on the hot discharge from the heater, then you probably have a retrofit circulation system, and there is a "4 port manifold" under one or more sinks which has to be replaced.

OK, now I'm going to need an plumbing to English translation. 4 port manifold??

I've been under all of the sinks and don't notice anything that is different from a standard sink fitting...

 

[Sponsor]

 

[Jadnashua]

For a recirculation system to function, it either needs a dedicated pipe for the return path, or (often used on retrofit situations), they use a special valve or manifold somewhere (usually at the sink furthest away from the WH - you could have more than one), to allow the hot water to return via the cold water line. So that you can actually get cold water out of that line, they don't leave that manifold or special valve assembly open for recirculation all of the time - only when needed as determined (usually) by a temperature sensing device. If the internal valve sticks or breaks, or wears out, it can remain open, and then the hot and cold lines are constantly interconnected. When you don't have a dedicated return line, the compromise is the increased complication (adding the manifold or valves) and that it DOES warm up the cold line. If it is operating properly, it won't make the cold line hot, but only warm. The overall design would determine by how much that cold line was warmed. Some are better than others.

If the design of the shower valve cartridge allows crossover when it fails (I hear that Mixet valves can have that problem - there are probably others as well), then it is generally an easy fix from the front after removing the handle. On some, you might also have to remove the trim, but usually not. Unless there is also a desire to update the entire valve and trim, there's no reason to tear into the wall. One good reason to change the entire valve is if it is old and does not contain the currently required anti-scald technology.

 

[Bustergordon]

Thanks. I'll take a look for a manifold or valve in the house when I get home.

I spoke to my plumber this morning (the info I had this morning was from a note he left me) and he is saying that we need to cut into my shower to fix this, which means completely retiling my bathroom. EEK! I'll keep running these suggestions down. He did say that the handle is a Price Pfister. He said he replaced the cartridge but it didn't fix the problem, so he wants to replace the entire valve, hence the tile cutting.

 

[Jadnashua]

There is nothing in a valve that could allow a crossover if the cartridge is working properly. He's guessing...and that can get expensive!

 

[dhla]

I also have a very reasonably priced tile guy in LA to recommend if you need him. I would describe him as a "tile savant." But as for plumbers, Jerry has fixed anything I've thrown his way.

 

[Ballvalve]

Once again and again, turn off the pump for a few days. Look for a breaker or follow the wire to where they lead to a breaker.You plumber is a ding bat if he wants to tear into a valve. Clueless in the extreme. You do not have a plumber, you have a parasite.

I have a lawyer in LA you can sue him with after he wrecks your tile and fails to fix anything.

 

[Bustergordon]

I'm almost afraid to write this and jinx things, but I think he may have fixed the problem without realizing it by changing the check valve. I've had cold water out of the cold taps now yesterday and this morning. I suspect it actually was the check valve, and he didn't fully get all of the hot water out of the system after replacing it, leading him to believe that it wasn't the check valve. Now that we've had a few days and time to get all of the hot water out of the cold line, it seems like we're getting cold water. Of course, I could be totally wrong, and this could all be a coincidence! I'm knocking wood as I write this!

That said, if the problem does come back, I'll look for the breaker for the pump and try to turn it off. From some internet searching that I did yesterday, the pump I have resembles a Grundfos recirculating pump...

 

[Bustergordon]

OK, I spoke too soon. Strangely after having 2.5 days of nice cold water, I'm back to scalding hot water coming out of my cold taps. I took a better look at the recirculating pump - it's definitely a Grundfos. It's just plugged in to the wall - can I unplug it without damaging anything and still have hot water from the water heaters?

 

[hj]

SOMEWHERE under one or more of the sinks, there is a "black piece of plastic" with FOUR pipes/hoses connected to it. THAT is what has finally failed, (they all do eventually), and needs to be replaced, assuming you are giving us the proper information. DO NOT let ANYONE tear your wall out. It would NOT fix anything and would waste a lot of your money. You can unplug the pump, but the situation would still exist, just at a lower level, such as then you might get cold water from the hot water faucets.

 

[Bustergordon]

SOMEWHERE under one or more of the sinks, there is a "black piece of plastic" with FOUR pipes/hoses connected to it. THAT is what has finally failed, (they all do eventually), and needs to be replaced, assuming you are giving us the proper information. DO NOT let ANYONE tear your wall out. It would NOT fix anything and would waste a lot of your money. You can unplug the pump, but the situation would still exist, just at a lower level, such as then you might get cold water from the hot water faucets.

Trust me, no one is tearing the wall out!

I've looked under every single sink for the manifold and don't see it anywhere. Could it be outside? Attached to a toilet or something else random? If I don't have one, is that the source of my problem perhaps?

 

[Jadnashua]

Do you have a dedicated recirculation line, or are you using the cold-water line as the return? If you are using the cold water as the return line, with only a check-valve, both the hot and cold line will become warm, as there's nothing to stop it. What's in that manifold is the cross-over and thermostatically controlled valve. Once that hot line gets to the desired temp, it shuts off the flow. In theory, you could do this with the pump, but some systems keep the pump running, and modulate the flow with a remote manifold.

If there are aquastats on the system, and it relies on the pump turning off once the hot line is charged with hot water, that sensor could be bad. This could be a clip-on sensor, or it could be in the pump.

Until you figure out what kind of recirculation system you have, it's hard to advise. I think you said the recirculation line was connected to the bottom of the WH. If so, is the T before or after the drain valve? IOW, could you just turn the pump off and close the line to see what happens? Obviously, you'd need to run the hot longer to get it when you open a valve, but it would tell you if the recirculation system is the cause of the cross-over. Keep in mind, ANY recirculation system that doesn't have a dedicated return line (i.e., uses the cold line) WILL make the cold water at least warm when working. A well-designed system won't make it hot.

On mine, flushing the toilet purges the warm water out of the cold to the bathroom faucet (a 1.6g toilet). Mine uses the cold line for recirculation. I also have mine adjusted so that instead of full hot, I only get warm at the vanity (my shower take-off is closer to the WH, so gets hot quicker). Depending on the layout of your pipes, the branches, and where the recirculation line is coming from would determine which lines get hot or warm.

 

[Bustergordon]

OK, I just went out and tried to take a picture of the setup. I'm learning a lot about plumbing, but have probably described things wrong, so hopefully this picture helps.



Let me know if you need better/different pictures...

Thanks again everyone for your help & patience!

 

[Jadnashua]

You can't cut and paste on this forum...when entering a response, scroll down to manage attachments, and upload the picture from there.

 

[Bustergordon]

Sorry for the technical difficulties in my previous post. Here are the photos.

 

[Ballvalve]

Unplug it for a bit and close one of those valves.....and see if problem disappears. From the looks of the soldering and the hanger and the galv tee, this is a very bad DIY job, and the whole system is thus suspect.

Maybe the plumber that wanted to tear out a wall installed this mess. No timer? Joke system.

You will save enough gas in a month to pay that "plumbers" service charge by bypassing it until you get enough money to have a real recirc put in.

Your plumber is not stumped - he IS a stump.

 

[Bustergordon]

Thanks - will do. He didn't install this...we moved into the house and it was already here. I'm surprised, however, that he doesn't think there's a problem with this system. I was also wondering about the timer, as I've read that that seems to be a good thing to have with this kind of system. I'm not sure what kind of amateur did the plumbing at this house before we moved in...the water heaters weren't strapped, and were vented with duct tape, not piping. Everything related to the water heaters has been something of a mess since we moved in. I think it's time for a different plumber to fix this mess.

 

[Jadnashua]

If you've got some control to throttle the flow once hot is at the point of use, and, you have insulated all of the lines that you can, it doesn't take a huge amount of energy to run recirculation. Only if the lines run through uninsulated space and are themselves uninsulated and it is circulating all of the time is it likely to start to get expensive. While a timer can help, it won't make a huge difference unless all of the logical things were ignored when it was installed. I typically turn mine off if I'm going to be away for more than a couple of days, but find that my gas and electric bills are often nearly the same as for the times I'm home. I was able to insulate (nearly) all of the lines when I did some remodeling, so that helps. But to say that it absolutely will cost a huge amount to run, is just not valid if any prudent steps are taken during its install.

 

[hj]

That is a conventional circulation system, so it does not use the "4 port valve", but it DOES need a check valve which is not shown in your pictures so you may not have one. It is also possible that the pump is installed backwards, but the pictures do not give enough detail to tell for sure.

 

[Ballvalve]

I wonder how this plumber managed to vent a water heater with duct tape? Stacked up all the cores with one turn of tape left on them and then taped over that? Or maybe he used the cardboard core from the carpet roll and taped that up. If he intalled the gas lines, I would get a forensic inspector to look over the house.

My guess is he is just pushing hot into the cold line and there are no return lines or valves anywhere. Confused guy.