Multiple tempering valves don't work

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John Gayewski

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I like caleffi products and support for problems like this. You can call them and get a real person. I think the problem has to be debris or something is outside of the perimeters of the design for this valve. I couldn't find very specific info for this valve.
 

Jeff H Young

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I like caleffi products and support for problems like this. You can call them and get a real person. I think the problem has to be debris or something is outside of the perimeters of the design for this valve. I couldn't find very specific info for this valve.
I agree a malfunction of the valve is very possible from trash in the line or whatever. the fact both valves are doing the samething puts doubt . Im still leaning towards following manufactures in placement of the check valve but cant say that it makes a differance, sure looks wrong to me though to have the hot and cold feeding the tempering valve at differant pressures
 

Chesterton

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Well, I'm back and the news isn't good. I removed the valve and union coupling and soldered on a couple of threaded ends. I put an analog WATT water pressure gage on each end (in turn) and let it sit for 10 minutes before taking the measurement. I measured flow rate (quantity of water into buckets at full throttle over one minute). I also measured the temperature of the water in the buckets. Note that I didn't start the clock on the hot water until the cold water had made its way through (i.e., we were at a steady state). The results:

cold side: 77 psi, 6 gpm, 54 degrees
hot side: 77 psi, 2.9 gpm, 144 degrees

I'm at a loss. I was hoping for there to be a large pressure difference. But the pressures are as close to equal as I can read on the gage. The water heater is working almost exactly to spec (flow rate at a temperature increase).

I originally was thinking that I would open up the y-check valves, but they're pretty tight so I just hit them a couple of times with the wrench :). They seem to be working properly based on the flow at the drain valve in various configurations.

The only thing that I can think of that's left is to increase the distance from the mixed outlet to the first bend (currently just 2"). Or get a third valve.
 

John Gayewski

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Well, I'm back and the news isn't good. I removed the valve and union coupling and soldered on a couple of threaded ends. I put an analog WATT water pressure gage on each end (in turn) and let it sit for 10 minutes before taking the measurement. I measured flow rate (quantity of water into buckets at full throttle over one minute). I also measured the temperature of the water in the buckets. Note that I didn't start the clock on the hot water until the cold water had made its way through (i.e., we were at a steady state). The results:

cold side: 77 psi, 6 gpm, 54 degrees
hot side: 77 psi, 2.9 gpm, 144 degrees

I'm at a loss. I was hoping for there to be a large pressure difference. But the pressures are as close to equal as I can read on the gage. The water heater is working almost exactly to spec (flow rate at a temperature increase).

I originally was thinking that I would open up the y-check valves, but they're pretty tight so I just hit them a couple of times with the wrench :). They seem to be working properly based on the flow at the drain valve in various configurations.

The only thing that I can think of that's left is to increase the distance from the mixed outlet to the first bend (currently just 2"). Or get a third valve.
Call caleffi. Have them listen to your situation and sell you the right valve
 

Jeff H Young

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Well, I'm back and the news isn't good. I removed the valve and union coupling and soldered on a couple of threaded ends. I put an analog WATT water pressure gage on each end (in turn) and let it sit for 10 minutes before taking the measurement. I measured flow rate (quantity of water into buckets at full throttle over one minute). I also measured the temperature of the water in the buckets. Note that I didn't start the clock on the hot water until the cold water had made its way through (i.e., we were at a steady state). The results:

cold side: 77 psi, 6 gpm, 54 degrees
hot side: 77 psi, 2.9 gpm, 144 degrees

I'm at a loss. I was hoping for there to be a large pressure difference. But the pressures are as close to equal as I can read on the gage. The water heater is working almost exactly to spec (flow rate at a temperature increase).

I originally was thinking that I would open up the y-check valves, but they're pretty tight so I just hit them a couple of times with the wrench :). They seem to be working properly based on the flow at the drain valve in various configurations.

The only thing that I can think of that's left is to increase the distance from the mixed outlet to the first bend (currently just 2"). Or get a third valve
I see no reason if you run the hot water why it wont get over 99 either tempering valve I guess bad? once the hot water is running for a short time the pressure should be equal and allow the valve to operate correctly, I guess the only reason to not blame the tempering valve is its new and we assume a new valve is good. of cource we have no idea if the first one is bad either only that you rebuilt it coulda been bad or good befor and after
only the one check valve could matter, the one on the cold near Xtank and we know thats not stuck closed as hot water is flowing freely which also means the check valve is open on the cold . the other check valves and piping could capped off and it wouldnt matter and the pump does nothing except emergency back up heat.
I dont see a problem with the 90 near the mixing valve. was that changed ? I still dont like the fact your check valve is installed wrong but cant say that is the cause and now thinking a good chance its not the problem .
So right back to the tempering valve I hate to say it and im not spending my money on the valve but what else ?
 

Chesterton

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I see no reason if you run the hot water why it wont get over 99 either tempering valve I guess bad? once the hot water is running for a short time the pressure should be equal and allow the valve to operate correctly, I guess the only reason to not blame the tempering valve is its new and we assume a new valve is good. of cource we have no idea if the first one is bad either only that you rebuilt it coulda been bad or good befor and after
only the one check valve could matter, the one on the cold near Xtank and we know thats not stuck closed as hot water is flowing freely which also means the check valve is open on the cold . the other check valves and piping could capped off and it wouldnt matter and the pump does nothing except emergency back up heat.
I dont see a problem with the 90 near the mixing valve. was that changed ? I still dont like the fact your check valve is installed wrong but cant say that is the cause and now thinking a good chance its not the problem .
So right back to the tempering valve I hate to say it and im not spending my money on the valve but what else ?
I agree. It seems like the conditions are such that everything should be working properly or close to properly. I'll call Caleffi and try valve #3.

One question: While I'm in here messing around I've been thinking about tightening up the piping. Right now the cold water for the mixing valve is "before" the expansion tank. Is it OK for me to put it "after" (i.e., between the expansion tank and the water heater)?

Thanks everyone for the help. I'll let you know how it shakes out.
 

Chesterton

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Set the flow rate at 5 gpm see what happens
Interesting idea! I'll try that when I get home.

Meanwhile, Caleffi recommended their 520 valve (which I ordered). It's going to require a reconfiguration of my piping, but that's small potatoes compared to the rest of this saga.
 

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The Apollo valve 34-200 is Not for potable water for either 85° to 120° or 120° to 180° they do not list a minimum flow rate. Called the factory they have to talk with engineering. They do list point of use flow rate from 1/2 to 3.6 gpm.
 

Fitter30

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Factory got back with me:
This is what I got back in response from Engineering: It does not meet a performance standard so we do not publish a minimum. Typically they are used with recirculation pumps for hydronic heating so low flow fixtures are not involved.
 

JohnCT

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cold side: 77 psi, 6 gpm, 54 degrees
hot side: 77 psi, 2.9 gpm, 144 degrees

You could still get 77 psi even with a valve 99% percent closed if you give it time.

The flow rate bothers me. I'm assuming the low flow rate on the hot side is the heater, but maybe it's a check valve? If you run into a dead end with this problem, I'd try putting a valve in line with the cold inlet and set if for roughly 3 gpm to match the hot flow rate. If that doesn't work, your next step is an exorcist...

John
 

Chesterton

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You could still get 77 psi even with a valve 99% percent closed if you give it time.

The flow rate bothers me. I'm assuming the low flow rate on the hot side is the heater, but maybe it's a check valve? If you run into a dead end with this problem, I'd try putting a valve in line with the cold inlet and set if for roughly 3 gpm to match the hot flow rate. If that doesn't work, your next step is an exorcist...

John
I just throttled the cold water and the results were the same. So looks like the exorcism is in order. We'll know tomorrow after I try the (third) valve.
 

John Gayewski

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Well, I'm back and the news isn't good. I removed the valve and union coupling and soldered on a couple of threaded ends. I put an analog WATT water pressure gage on each end (in turn) and let it sit for 10 minutes before taking the measurement. I measured flow rate (quantity of water into buckets at full throttle over one minute). I also measured the temperature of the water in the buckets. Note that I didn't start the clock on the hot water until the cold water had made its way through (i.e., we were at a steady state). The results:

cold side: 77 psi, 6 gpm, 54 degrees
hot side: 77 psi, 2.9 gpm, 144 degrees

I'm at a loss. I was hoping for there to be a large pressure difference. But the pressures are as close to equal as I can read on the gage. The water heater is working almost exactly to spec (flow rate at a temperature increase).

I originally was thinking that I would open up the y-check valves, but they're pretty tight so I just hit them a couple of times with the wrench :). They seem to be working properly based on the flow at the drain valve in various configurations.

The only thing that I can think of that's left is to increase the distance from the mixed outlet to the first bend (currently just 2"). Or get a third valve.
I'm not sure exactly how your conducted this test. You measured the static pressure on both sides? The static pressure with no flow will be exactly the same. The way to measure the pressure (dynamically) would be from a tee while each side is running and with the same size opening. That would tell you how much pressure the valve is getting on each side during a flow situation. Also both of those numbers seem very low for full flow from a 3/4" pipe running at 77 psi.
 

JohnCT

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I just throttled the cold water and the results were the same. So looks like the exorcism is in order. We'll know tomorrow after I try the (third) valve.

Going on what John G above said, I wonder if the low hot water flow and the intentionally throttled cold water (good try I think) might be aggravating the valve - IOW, it might need a higher flow rate and pressure to work.

Interested to see how the third valve does. I have a Honeywell thermo mixer like yours and it works perfectly.

John
 

Jeff H Young

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i dont see why 2.9 gpm cant bring water to above 99 degrees 150 degrees regardless of flow rate should work unless the fixture demand is too high but a gallon a minute out a lav it should be hot not under 100 all the way back at the tempering valve . So Im not seeing the flow as the reason for low temp water
 

Reach4

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The photos I find of the Apollo 34-200 have a yellow knob. Your knob looks gray in the photo.
 
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Jeff H Young

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Factory got back with me:
This is what I got back in response from Engineering: It does not meet a performance standard so we do not publish a minimum. Typically they are used with recirculation pumps for hydronic heating so low flow fixtures are not involved.
Thanks for looking into this so deeply for Chesterton! Im pretty puzzled and racked my brain a bit myself Kinda stuck on it being another bad temporing valve though I feel dumb without a better answer havent checked into whether either valve was correct for this application . The fact its an emergency back up for heat makes me assume the pump is rarely used makeing this a non circulating system low flow . Any opinion from the experts at manufacture the valve is incappable of flowing small amounts at a preset temperature? example if a 1/2gpm is called for by a lav that a properly operating valve wont provide a mix at 120 degrees because the flow isnt sufficient?
 

John Gayewski

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Thanks for looking into this so deeply for Chesterton! Im pretty puzzled and racked my brain a bit myself Kinda stuck on it being another bad temporing valve though I feel dumb without a better answer havent checked into whether either valve was correct for this application . The fact its an emergency back up for heat makes me assume the pump is rarely used makeing this a non circulating system low flow . Any opinion from the experts at manufacture the valve is incappable of flowing small amounts at a preset temperature? example if a 1/2gpm is called for by a lav that a properly operating valve wont provide a mix at 120 degrees because the flow isnt sufficient?
This is Wendy I've suspected for a while. The internet doesn't really provide full info on his valve. It really has to improper valve or pipe obstruction I think.
 
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