# dumb dumb



## justme (Jul 4, 2012)

I usually don't post pictures but one of my guys ran across something that just made me shake my head today. We were called out to figure out why the public lavs were not getting hot water, we show up and they take us to the water heater closet and show us this work another plumber did very recently. As you can see in the pic there is a new mixing valve and new recirc pump installed, so we trace it out and discover these idiots install3e a pump on a tempered water line but there isn't a recirc loop back to the heater to allow for circulation so it dead heading into the stops at lavs.lol
I get with the manager and he says the owner of the other company told them that they needed new manual lav faucets in order for this setup to work, what ?? They have low flow Toto 105's and they have nothing to do with the circ pump. Apparently CFA called them out to fix the hot water not getting to the lavs fast enough and this was their fix. So I gave them a quote to run the circ line from the lavs back to the water heater 100'+ or install insta hots at the lavatories. The health inspector keeps busting them on it taking 2 minutes plus to get 105 degree water to the faucets. Yes we did unplug the pump since it wasn't circulating anything lmfao. Guys like this give us all a bad name.


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## ShtRnsdownhill (Jan 13, 2016)

hire the handicapped they are more fun to watch... :vs_laugh::vs_laugh::vs_laugh:


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## Tommy plumber (Feb 19, 2010)

Code states that even for residential, if the W/H is 100' or more from the furthest fixtures, then the house needs a re-circ. line. But to omit it from a commercial job is a big no-no. 

I'm curious if a re-circ. line was on the original set of prints. But even if it wasn't, the plumbers should have caught that.

I was on a commercial job years ago running copper water lines in a multi-story building. The print showed a 1/2" copper re-circ. line tie back into a cold line. I knew it was wrong. So I went to the foreman. He sent in a RFI. They got back to us and said yeah the print is wrong. Don't do it like the print is showing.


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## Toli (Nov 7, 2015)

A circ line isn’t gonna work with that tempering valve anyway.


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## justme (Jul 4, 2012)

Toli said:


> A circ line isn’t gonna work with that tempering valve anyway.


the right sized pump will work with that mixing valve.


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## Venomthirst (Jun 20, 2018)

Toli said:


> A circ line isn’t gonna work with that tempering valve anyway.


Exactly... should be tempered at fixtures water be ice by time it reaches them


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## justme (Jul 4, 2012)

Venomthirst said:


> Exactly... should be tempered at fixtures water be ice by time it reaches them


Not with a recirc line pulling from the tempered line at the fixture but I do agree by code there should be a 1070 compliant device at each fixture.


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## Toli (Nov 7, 2015)

justme said:


> the right sized pump will work with that mixing valve.




And return to the heater?


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## Venomthirst (Jun 20, 2018)

justme said:


> Venomthirst said:
> 
> 
> > Exactly... should be tempered at fixtures water be ice by time it reaches them
> ...


What I mean is have your mixing valve before your bank of fixtures and run your loop back not tempered back hot back . to tank.. its definitely asanine but not all hope is lost there just add a pipe and switch a few things around to make it a happy little bathroom group...


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## justme (Jul 4, 2012)

Toli said:


> And return to the heater?


Yes


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## justme (Jul 4, 2012)

Venomthirst said:


> What I mean is have your mixing valve before your bank of fixtures and run your loop back not tempered back hot back . to tank.. its definitely asanine but not all hope is lost there just add a pipe and switch a few things around to make it a happy little bathroom group...


Agreed, the proper way would be to discontinue the mixing valve at the water heater, turn the tempered water line into a hot line, then put point of use mixing valve at the fixtures and run a recirc line back from the fixtures to the water heater but CFA is not interested in spending that kind of money lol.


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## Toli (Nov 7, 2015)

justme said:


> Yes


When you circ tempered water at say 110 degrees back to the heater, that means you are trying to push untempered water through the tempering valve. The only way to make tempered water is to add cold water to it, except you can't add cold water to it if no water is being drawn. 

You might be able to pipe your return into the inlet of the tempering valve and the heater and balance it with ball valves. Some manufacturer's show that. 

But i agree that putting valves at the fixtures and circing untempered is better.


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## justme (Jul 4, 2012)

Toli said:


> When you circ tempered water at say 110 degrees back to the heater, that means you are trying to push untempered water through the tempering valve. The only way to make tempered water is to add cold water to it, except you can't add cold water to it if no water is being drawn.
> 
> You might be able to pipe your return into the inlet of the tempering valve and the heater and balance it with ball valves. Some manufacturer's show that.
> 
> But i agree that putting valves at the fixtures and circing untempered is better.



By creating a recirc loop and having the tempering valve in place, the valve won't allow untempered water through the tempering valve it will pull cold and hot just as the tempering valve is designed.


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## Toli (Nov 7, 2015)

justme said:


> Toli said:
> 
> 
> > When you circ tempered water at say 110 degrees back to the heater, that means you are trying to push untempered water through the tempering valve. The only way to make tempered water is to add cold water to it, except you can't add cold water to it if no water is being drawn.
> ...


Agreed. But you can’t add cold water to system unless a faucet is turned on.


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## Toli (Nov 7, 2015)

This is kinda what I’m talking about. The return has to to the heater and to the mixing valve. If you send the tempered return just to the heater the mixing valve can’t draw in cold water because there’s no place for it to go.


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## Tango (Jan 13, 2018)

Toli said:


> This is kinda what I’m talking about. The return has to to the heater and to the mixing valve. If you send the tempered return just to the heater the mixing valve can’t draw in cold water because there’s no place for it to go.


In my mind it doesn't make sense. A return will only run when the flow is in demand and then tempered water mixed with cold water before the mixing it again? Am I getting this completely wrong? You are still going to wait 2 minutes before you have water at the faucet. No?


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## Toli (Nov 7, 2015)

Tango said:


> Toli said:
> 
> 
> > This is kinda what I’m talking about. The return has to to the heater and to the mixing valve. If you send the tempered return just to the heater the mixing valve can’t draw in cold water because there’s no place for it to go.
> ...


I assume you’re talking about the piping diagram I posted?

If you look at the diagram, you’ll see what they are calling a balancing valve on the return before it connects to the heater. This balancing valve is used to restrict the flow back to the heater. So in periods of no usage, the circ is sending water back to the heater and mixing valve. So you would have straight hot and tempered water feeding the mixing valve. The valve will then compensate for the raised cold water inlet temp and adjust accordingly to hit your set point. Basically, you have to have flow through the hot and cold side of the valve when there is no faucets running in order for the valve to work. 

I used a Leonard valve piping diagram. They have a specific piping diagram and specific process for balancing the system. Other valves manufacturer’s may be different. Attached is another way from Leonard for a different style valve. It has a return port on the valve. The principles are the same. 

What I do know is if you just send the return back to the heater it will not circulate tempered water. I know this because I was once smarter than the manufacturer and didn’t do it their way. And it would not work.


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## justme (Jul 4, 2012)

Tango said:


> In my mind it doesn't make sense. A return will only run when the flow is in demand and then tempered water mixed with cold water before the mixing it again? Am I getting this completely wrong? You are still going to wait 2 minutes before you have water at the faucet. No?



A return line will run as long as the recirc pump is pulling water. The mixing valve will allow both hot and cold water through the valve into the tempered water line as long as you have a properly sized pump to pull the minimum water through to activate the mixing valve which is normally .5 gpm. As for the statement that the cold has nowhere to go, well it well go back to the water heater through the tempered water line, that's the whole point of the loop.


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## justme (Jul 4, 2012)

Toli said:


> I assume you’re talking about the piping diagram I posted?
> 
> If you look at the diagram, you’ll see what they are calling a balancing valve on the return before it connects to the heater. This balancing valve is used to restrict the flow back to the heater. So in periods of no usage, the circ is sending water back to the heater and mixing valve. So you would have straight hot and tempered water feeding the mixing valve. The valve will then compensate for the raised cold water inlet temp and adjust accordingly to hit your set point. Basically, you have to have flow through the hot and cold side of the valve when there is no faucets running in order for the valve to work.
> 
> ...


I agree this beast $750.00 mixing valve will only work if installed per Leonards directions. They typically have multiple diagrams of how they want it piped in and it won't work unless you pipe it in their way, learned the hard way. But not all mixing valves are created equal, Leonard is a particular brand that is usually spec'd out on higher end jobs because they work very well in high flow gpm situations and are great mixing valves but very expensive. The last one I bought was for a food storage facility and the damn thing cost around 2200.00 because it had to have 40 gpm flow with the lowest pressure drop possible. But leonard is not the only mixing valve on the market especially in low flow gpm situations.


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## Toli (Nov 7, 2015)

justme said:


> I agree this beast $750.00 mixing valve will only work if installed per Leonards directions. They typically have multiple diagrams of how they want it piped in and it won't work unless you pipe it in their way, learned the hard way. But not all mixing valves are created equal, Leonard is a particular brand that is usually spec'd out on higher end jobs because they work very well in high flow gpm situations and are great mixing valves but very expensive. The last one I bought was for a food storage facility and the damn thing cost around 2200.00 because it had to have 40 gpm flow with the lowest pressure drop possible. But leonard is not the only mixing valve on the market especially in low flow gpm situations.


Totally agree. I was just using the diagram as an example. I have no love for leonard but they are popular around here.


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## Toli (Nov 7, 2015)

justme said:


> A return line will run as long as the recirc pump is pulling water. The mixing valve will allow both hot and cold water through the valve into the tempered water line as long as you have a properly sized pump to pull the minimum water through to activate the mixing valve which is normally .5 gpm. As for the statement that the cold has nowhere to go, well it well go back to the water heater through the tempered water line, that's the whole point of the loop.


This is where I respectfully disagree. The water heater and associated piping hold a fixed amount of water. It simply can't draw in cold water during periods of no use because the system is full of water and you can't add water to a full system.


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## Toli (Nov 7, 2015)

I sent you a pm, justme.


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## justme (Jul 4, 2012)

Toli said:


> This is where I respectfully disagree. The water heater and associated piping hold a fixed amount of water. It simply can't draw in cold water during periods of no use because the system is full of water and you can't add water to a full system.


I'm going to have to say after doing some research on the mixing valve that is in there you're right Toli. The only way to make it work would be to tie the recirc line into the cold feeding the mixing valve with a check and then run the recirc back to the tank with another check, This would complete the loop and allow tempered water to flow freely to the fixture. I'm hard headed but when I found the diagram for the mixing valve that is in there I had to shake my head and tell my myself don't be such a stubborn ass and listen sometimes.


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## Toli (Nov 7, 2015)

justme said:


> Toli said:
> 
> 
> > This is where I respectfully disagree. The water heater and associated piping hold a fixed amount of water. It simply can't draw in cold water during periods of no use because the system is full of water and you can't add water to a full system.
> ...


Hallelujah! He’s seen the light, lol. 

Seriously, take it as an opportunity to learn from MY mistake instead of yours.


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