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Discussion Starter · #1 · (Edited)
Recently I've been trying to figure out hot water problems at a clients house. The client complained of intermittent lukewarm only water when showering and doing dishes. This happened maybe once a week on average. It had gotten to the point where she had her water heater tuned up to beyond the "C" level. At that level the temp of water coming out of the pressure & overflow valve only being at 123 degrees. When turned maybe 1/4" to the "very hot" and letting the tank cook, I got 143 degrees. First off in my mind the "C" level should be way above 123. Being that the 75 gal tank was still under warranty, I got Rheem to send me a new gas valve. Installed yesterday, and "A" level is now producing 128 degrees. However, the problem seems to persist some. I refilled the tank and let it get up to temp and then ran the master shower...with again only lukewarm water coming out. (the max temp scald setting on the shower mixing valve has been maxed out.)

The tank has a re-circulator installed on the 4 year old house in CA. I've attached 2 pics of the setup and I wanted to get some insight from you all if you think the re-circulator setup looks correct or not. Not sure if the re-circulator is mixing cold back into the system, or not seeming to recirculate correctly or at all. I've currently got the re-circ pump turned off, and the valve in that line closed to possibly eliminate that as a cause. The only issue now is that it takes 5+ mins. for hot to get to the kitchen on the other side of the 3500 Sq. Ft. house.


Possible issues: Bad mixing valve at shower or kitchen sink?
Bad re-circ pump? because the "HOT" on a good day isn't really too quick to get there.
Is an air dam in the recirc line a possible issue?
Clogged re-circ pump with debris? Is there a strainer on the inlet side?

Your thoughts??

Thanks!
Pete
 

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PlumbingZone Reject
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It seems to be missing a check valve on the cold side -- It should be on the 3/4" cold feed, just after the ball valve and *before* the tee where the circ line ties in.

The omission of this check valve will allow hot water from the circulating pump to push into the cold system.
 

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Discussion Starter · #3 ·
It seems to be missing a check valve on the cold side -- It should be on the 3/4" cold feed, just after the ball valve and *before* the tee where the circ line ties in.

The omission of this check valve will allow hot water from the circulating pump to push into the cold system.
I do understand what you're saying and agree...however that would create more of a "warm" issue coming out of the cold, correct? My issue seems to be more of what may be cold getting into the hot side, making it not hot enough at times. There is a check valve (I believe) that you can see behind the vent pipe keeping at least the water going in the correct direction in the loop that it's supposed to, however not blocking the issue you're pointing out.

I feel like the re-circ line isn't keeping nearly as hot as the tank...which I would assume that it should be all the time it is running, within a few degrees, right?
 

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I think your plumber messed up. At least on some Rheem water heaters the top right plumbing is the cold supply supply, and it appears to me that the recirc pump in your case is connected into that cold water supply.

Even if you were tapped into the hot, that's not how my plumbers do recirculating pumps; the plumber puts a new pipe out of the drain connector low on the heater, with one side to the drain valve and the other to the recirc pump. The pump pulls hot water out through the house, through the hot water plumbing, and brings it back through the recirc piping into the heater at the drain fixture.

Edit: To expand on the comment about the drain plug - even if you were tapped into the hot water pipe out, you still wouldn't really be moving hot water out through the house. You'd be pumping water in a circle that doesn't include the hot water in the heater.

Edit again: Taco recommends plumbing recirculators as I mention above.

And edit again: I'm suspicious of the closely soldered copper coming out of the bottom of that pump. Maybe Taco pumps are different, but I'm accustomed to seeing a big flanged dielectric union or other such thing on recirculators. I don't like the 80 degree angle, either. I'd be wondering how long it will be before the vibration and galvanic action and lack of support cause that thing to flop off of there and fill your customer's basement with water.

I just don't like the look of it.
 

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I do understand what you're saying and agree...however that would create more of a "warm" issue coming out of the cold, correct? My issue seems to be more of what may be cold getting into the hot side, making it not hot enough at times. There is a check valve (I believe) that you can see behind the vent pipe keeping at least the water going in the correct direction in the loop that it's supposed to, however not blocking the issue you're pointing out.

I feel like the re-circ line isn't keeping nearly as hot as the tank...which I would assume that it should be all the time it is running, within a few degrees, right?
It's hard to say how it will operate until the system is piped correctly and allowed time to balance itself out.
 

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I think your plumber messed up. At least on some Rheem water heaters the top right plumbing is the cold supply supply, and it appears to me that the recirc pump in your case is connected into that cold water supply.

Even if you were tapped into the hot, that's not how my plumbers do recirculating pumps; the plumber puts a new pipe out of the drain connector low on the heater, with one side to the drain valve and the other to the recirc pump. The pump pulls hot water out through the house, through the hot water plumbing, and brings it back through the recirc piping into the heater at the drain fixture.

Edit: To expand on the comment about the drain plug - even if you were tapped into the hot water pipe out, you still wouldn't really be moving hot water out through the house. You'd be pumping water in a circle that doesn't include the hot water in the heater.

Edit again: Taco recommends plumbing recirculators as I mention above. Get a new plumber.
Since the hot outlet is a part of the circulating loop, tying into it would defeat the purpose of creating a loop.

Circulating lines are tied into the cold side because the dip tube forces the hot water into the bottom of the tank -- It's pretty much the same reason why some Plumbers will connect the return to the drain outlet.

I prefer to tie into the cold inlet mostly because it makes it easier to replace the tank down the road should replacement become necessary.
 

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And edit again: I'm suspicious of the closely soldered copper coming out of the bottom of that pump. Maybe Taco pumps are different, but I'm accustomed to seeing a big flanged dielectric union or other such thing on recirculators. I don't like the 80 degree angle, either. I'd be wondering how long it will be before the vibration and galvanic action and lack of support cause that thing to flop off of there and fill your customer's basement with water.

I just don't like the look of it.
It's definitely a sub-par installation.
 

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Discussion Starter · #8 ·
I think your plumber messed up. At least on some Rheem water heaters the top right plumbing is the cold supply supply, and it appears to me that the recirc pump in your case is connected into that cold water supply.

Even if you were tapped into the hot, that's not how my plumbers do recirculating pumps; the plumber puts a new pipe out of the drain connector low on the heater, with one side to the drain valve and the other to the recirc pump. The pump pulls hot water out through the house, through the hot water plumbing, and brings it back through the recirc piping into the heater at the drain fixture.

Edit: To expand on the comment about the drain plug - even if you were tapped into the hot water pipe out, you still wouldn't really be moving hot water out through the house. You'd be pumping water in a circle that doesn't include the hot water in the heater.

Edit again: Taco recommends plumbing recirculators as I mention above.

And edit again: I'm suspicious of the closely soldered copper coming out of the bottom of that pump. Maybe Taco pumps are different, but I'm accustomed to seeing a big flanged dielectric union or other such thing on recirculators. I don't like the 80 degree angle, either. I'd be wondering how long it will be before the vibration and galvanic action and lack of support cause that thing to flop off of there and fill your customer's basement with water.

I just don't like the look of it.

I hear you....however what you're looking at makes sense to me, and possibly you're mis-understanding the piping here. The pipe coming out of the wall furthest right with the green handled shut off is the returned heated re-circ line.....that goes into the bottom of the pump, now pumped, then through a check valve and into the cold side inlet of the heater. Bringing the now re-circulated lukewarm water down into the bottom of the heater via the dip tube with the any cold water (only if hot is running in the house) to be heated. Your way makes sense as well, but so does this...to me at least. The water that is getting pulled through house and the re-circ line is from the HOT side and the HOT only. (The left flex in the pic.)
 

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Discussion Starter · #10 ·
Since the hot outlet is a part of the circulating loop, tying into it would defeat the purpose of creating a loop.

Circulating lines are tied into the cold side because the dip tube forces the hot water into the bottom of the tank -- It's pretty much the same reason why some Plumbers will connect the return to the drain outlet.

I prefer to tie into the cold inlet mostly because it makes it easier to replace the tank down the road should replacement become necessary.

Yes, correct on the loop.
 

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...however what you're looking at makes sense to me, and possibly you're mis-understanding the piping here....
Thanks, of course you're correct. I haven't seen it that way before.

Now as long as I'm treading on thin ice, I have no shame, so why not wander farther out into the middle of the pond.... I can't see the direction of the check valve or the cartridge on the pump. What if they're on backwards, and the pump is pushing cold water out the recirc loop when the water is flowing?
 

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Recently I've been trying to figure out hot water problems at a clients house. The client complained of intermittent lukewarm only water when showering and doing dishes. This happened maybe once a week on average. It had gotten to the point where she had her water heater tuned up to beyond the "C" level. At that level the temp of water coming out of the pressure & overflow valve only being at 123 degrees. When turned maybe 1/4" to the "very hot" and letting the tank cook, I got 143 degrees. First off in my mind the "C" level should be way above 123. Being that the 75 gal tank was still under warranty, I got Rheem to send me a new gas valve. Installed yesterday, and "A" level is now producing 128 degrees. However, the problem seems to persist some. I refilled the tank and let it get up to temp and then ran the master shower...with again only lukewarm water coming out. (the max temp scald setting on the shower mixing valve has been maxed out.)

The tank has a re-circulator installed on the 4 year old house in CA. I've attached 2 pics of the setup and I wanted to get some insight from you all if you think the re-circulator setup looks correct or not. Not sure if the re-circulator is mixing cold back into the system, or not seeming to recirculate correctly or at all. I've currently got the re-circ pump turned off, and the valve in that line closed to possibly eliminate that as a cause. The only issue now is that it takes 5+ mins. for hot to get to the kitchen on the other side of the 3500 Sq. Ft. house.


Possible issues: Bad mixing valve at shower or kitchen sink?
Bad re-circ pump? because the "HOT" on a good day isn't really too quick to get there.
Is an air dam in the recirc line a possible issue?
Clogged re-circ pump with debris? Is there a strainer on the inlet side?

Your thoughts??

Thanks!
Pete

This layout has me baffled to say the least. Lets presume that the pipe coming through the wall to the right with the green valve handle is a return then its going into a pump then through a check valve then past the expansion tank into the cylinder then off to faucets. So where on earth is the makeup water :blink:

If the Makeup water is being put anywhere into the circuit other than the cylinder then that could be your issue.
 

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Discussion Starter · #15 · (Edited)
This layout has me baffled to say the least. Lets presume that the pipe coming through the wall to the right with the green valve handle is a return then its going into a pump then through a check valve then past the expansion tank into the cylinder then off to faucets. So where on earth is the makeup water :blink:

If the Makeup water is being put anywhere into the circuit other than the cylinder then that could be your issue.
Makeup water? You mean the cold (main) coming into the tank when someone turns on a hot faucet inside? The cold is coming into the tank just behind the expansion tank. Shut off valve for that is just behind the tee where the re-circ pump puts it in. I know the pics are a bit difficult to differentiate whats going on....but you can barely see a bit of blue, half-painted shut off handle on the right side of the pipe just below the expansion tank on one of the pics.
 

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Discussion Starter · #16 ·
Thanks, of course you're correct. I haven't seen it that way before.

Now as long as I'm treading on thin ice, I have no shame, so why not wander farther out into the middle of the pond.... I can't see the direction of the check valve or the cartridge on the pump. What if they're on backwards, and the pump is pushing cold water out the recirc loop when the water is flowing?

Ya, I checked those...they're correct. Going UP in the pump and RIGHT in the check valve behind the vent stack. I wish it was something so dumb.
 

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Makeup water? You mean the cold (main) coming into the tank when someone turns on a hot faucet inside? The cold is coming into the tank just behind the expansion tank. Shut off valve for that is just behind the tee where the re-circ pump puts it in. I know the pics are a bit difficult to differentiate whats going on.
I thought it was a pushfit cap but i wondered if it was a coupling or fitting. hard to see from pics.

Next question is does the cold line have a check valve so that the hot cant back feed into the cold? Hot water in your drinking water line is not good.

Also have you tried shutting off the cold to the faucets and just running hot?
 

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Thanks, of course you're correct. I haven't seen it that way before.

Now as long as I'm treading on thin ice, I have no shame, so why not wander farther out into the middle of the pond.... I can't see the direction of the check valve
The pump would be burned up after 4 years if the check was backwards.

or the cartridge on the pump.
The core only goes in one way. It's idiot proof.

What if they're on backwards, and the pump is pushing cold water out the recirc loop when the water is flowing?
You'd have to be a special kind of stupid (and a machinist) to phac it up that badly.
 
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