I finally got a mixer valve for my Indirect fired domestic hot water heater.

Jean-David Beyer

As I get older, I assume my immune system may be declining, so I finally got the money together to add a mixer valve to my indirect so the indirect can run hot, but supply only 120F water to the house. I suppose I could have done this myself, but I am glad I did not.

The valve is one of these:

http://www.caleffi.com/usa/en-us/catalogue/scald-protection-point-use-thermostatic-mixing-valve-sweat-521349a

I had three ball valves added in the obvious places, and the connections to the valves are unions. Inside the two input lines are check valves and screen-type filters. There is a thermometer on the hot water input and on the mixed water output. It is now set to 150F input and 120F output. On my W-M tank-within-a-tank indirect is a dial with lines on it. One of the lines is a very different color from the others, although none of them are numbered. Their installation manual suggests setting the unit to that point. When first installed, I did that, but the hot water in the house came out at about 140F that was too high for convenient use. So I dialed it down to get 120F from the closest hot water tap (in my shower). When the new valve was put in, I dialed it back up to that line, and the input thermometer reveals it is about 150F, though it goes down a bit before the indirect asks for heat from the boiler. Not a surprise. I think I will just leave it there. I would like it to stay at 140F at its lowest. The valve will take up to 185F or so.

I had a professional plumber do it because I did not want to deal with the hassle of not having a part, or having a surprise. Surprises when doing plumbing are like surprises when running an insurance company: all surprises are bad.

Actually only one surprise occurred and I might well have not known how to solve it. When the plumber first pressure tested it after putting it all together, there was a faint drip on the wall. At first he supposed he made a bad solder joint, but in fact, he had not. An 90 degree elbow had a pinhole leak between the two ends. That would never have occurred to me, but he said it happens surprisingly often. I suppose those things are now all made in China, too.

Of course, once the plumber left, I tried a few experiments, and was disappointed to find my bathtub would no longer drain. The plumber's fault, of course (just kidding). I fished the hair from the drain and that did not help. I tried flushing with water pressure, and that did no good. A "plumber's friend" fixed it, though. Thank goodness.

STEVEusaPA

Isn't that the wrong valve? I thought a point of use valve goes at the fixture and a point of distribution valve goes on the indirect.

Jean-David Beyer

Good point, but according to their installation instructions, it can be so-used.

I think this is the link to the .pdf that shows that.
http://www.caleffi.com/sites/default/files/file/38531_na.pdf

On page 4.
The Caleffi 5213 series is a thermostatic mixing valve suitable for single or multiple point of use applications in accordance with installation rules and indications specified in ASSE 1070
standards.

Also see the figures on page 7.

icesailor

STEVEusaPA said:

Isn't that the wrong valve? I thought a point of use valve goes at the fixture and a point of distribution valve goes on the indirect.

I agree with that. I think that is the wrong application for that valve. None of the PDF photo's show a "Point Of Distribution" application. Just point of use.

I think that you needed a 521 Series valve.

Gordy

JD the only thing I see is mixer in a multi point of use sensor faucet application. Such as a public rest room.

Maybe Hot Rod will chime in. I think pressure balance may be an issue.

icesailor

You need a POD valve. When properly heat trapped, you don't need the checks. A POU valve is the wrong application for that valve.

Read the second PDF and the applications.

hot_rod

Generally that valve is used at the fixture location as the final protection device. To meet the ASSE 1070 standard it is limited to 120F max,. temperature.

An ASSE 1017, Calreffi 521 series, valve usually installed at the tank, it has a wider temperature adjusting range, and a higher Cv.

A 1070 valve must have the checks installed to meet the listing, true it works without them.

The ASSE website has a good overview of the various listings and intended applications.

One point to keep in mind is it is a 2 Cv valve, so depending on how many gpm you would flow at a full load condition you will experience some pressure drop.

If it is not causing excessive pressure drop, and the 120F is adequate for your temperature, it will work fine.

Does it have a recirc pump connected?

Jean-David Beyer

You do not believe Caleffi when they say (on page 4):
"The Caleffi 5213 series is a thermostatic mixing valve suitable for single or multiple point of use applications in accordance with installation rules and indications specified in ASSE 1070 standards."?

And when they give the example of one of these valves driving two sinks and a bath-tub? (on page 7)

"An ASSE 1017, Calreffi 521 series, valve usually installed at the tank, it has a wider temperature adjusting range, and a higher Cv."

I do not need a wider temperature adjusting range, and the Cv is high enough for me. Furtheremore, Caleffi say, "Caution: If the anti-scald function is required, use Caleffi 5213 series mixing valves which offer high thermal performance." Furthermore, the 521 series require 5 litres per minute minimum flow, and if I am using just a shower with low flow head, I may not be operating that valve in its regulating range. The 5213 will work with 2 litres per minute.

"A 1070 valve must have the checks installed to meet the listing, true it works without them."

The 5213 valve I have came with the check valves (and strainers), so it does not matter if it works without them or not.

"If it is not causing excessive pressure drop, and the 120F is adequate for your temperature, it will work fine."

I have lots of pressure, and 120F is what I want out of that valve.

Jean-David Beyer

"JD the only thing I see is mixer in a multi point of use sensor faucet application. Such as a public rest room."

That is the third of three examples. The first has a valve on every device; i.e., a single point of use. The second has a valve driving three devices (2 washbasins and one bath tub). The third has the valve driving a series of sensor faucets from the mixed output of the valve. Mine is set up as in the second illustration. I.e., as they say "The Caleffi 5213 series is a thermostatic mixing valve suitable for multiple point of use applications."

Gordy

Multi point use, and point of distribution are the two terms you are not distinguishing between their meanings.


Like HR said it may work put pressure drop could be an issue. Just so anyone else reading understands. Really wrong hardware for the application.

icesailor

And the counter sales person's should know and understand that distinction.

hot_rod

I contacted ASSE to see if there is any opinion from their listing as to why or why not a 1070 could be used as a point of distribution valve. I've not heard back yet.

The valve you have must pass a more stringent test protocol compared to a 1017 POD valve. It MUST have checks included, it responds quicker and has a tighter control over temperature.

I read through the testing requirements for both 1070 and 1017, nothing in their testing spec indicates the 1070 is ONLY for point of use.

some manufacturers go for a dual listing on their valves, which is even more confusing for the installer and inspectors.

The ASSE numbers are s bit confusing, even the folks on their committees will tell you that. the standards do get changes, or tightened every few years so we have an entire department that keeps up to date on the various listings required around the world, and there are hundreds!

We had Julius Balance and engineer on those code committees present a webinar a few years back, he referred to the "alphabet soup" of ASSE thermostatic mixing devices listing numbers and test procedures.

Un;ess an inspector or AHJ interperts the code or listing differently I cannot find a reason not to use the valve as you have.

When I hear back from our contact at ASSE I will update.

Enjoy the accurately mixed DHW in the meantime.

Gordy

The way I'm seeing it is purely from a pressure,drop,stand point, and the differing cv of the two. Point of distribution is going to need more flow verses point of use.

Knowing a little about JD I'm sure being only one person he does not have to worry about having a washer, dish washer, two showers running, to cause significant pressure drops. But what if he sells the house, and a large family moves in?

hot_rod

Here is the chart that shows pressure drop across the valve at various flow rates for the 5213, which has a 2 Cv.

Unless there is a high flow faucet, like a tub filler, i doubt you will notice the pressure drop when showering or washing the dishes

hot_rod

Rich_49

Jean David exceeded code requirements here . He used a better device in a place that it does not impeded pressure and can deliver the required GPM at all outlets . He also took into account that the 1017 device or temperature actuated mixing valve could have less flow than what would be optimal . Guys come on , you know what you know and exceeding code and recognizing , might I add what the average plumber does not is not a bad thing . the numbers are the numbers and JD hit them very well here . remember , the AHJ cannot fail you for exceeding code , which is exactly what JD did here . Good for you . I am kinda pissed you did not contact me for this though .

icesailor

This string started because there was a problem with temperature control with the valve he used.

Some of us maybe were trying to sat that he used a POU valve where a POD valve was what was called for. In the experience of some here that have installed a lot of POD valves on water heaters, we have never noticed a problem like that.

My experience with POD valves is that if you use one that is rated for 80 degree to 180 degree outlets, you can't control the water temperature. It never gets to 120 degrees, no matter what you do. 140 degree valves work like a charm.

hot_rod

I'm not reading where he has a problem with the mixer? the drain, maybe?

Rich_49

Ice , what are you talking about ? He used a 1070 device that shall be rejected if at any time temp can exceed 120* .
http://scaldprevention.org/ASSE 1017.htm

Jean-David Beyer

"Knowing a little about JD I'm sure being only one person he does not have to worry about having a washer, dish washer, two showers running, to cause significant pressure drops. But what if he sells the house, and a large family moves in? "

If a large family moves in, they are going to have way more problems than a temperature control valve with too much flow resistance. The house has only one bathroom. The existing plumbing is buried in the concrete slab, and is all 1/2 inch copper except part of the radiant heating system, where it enters as five 1/2-inch tubes and exits as one 1-inch tube. If anyone tries to put bigger than 1/2 inch water lines into that slab, they will, by Murphy's law, hit one of the radiant tubes. Then they will have to do a slab transplant.

Jean-David Beyer

"Like HR said it may work [b]ut pressure drop could be an issue. Just so anyone else reading understands. Really wrong hardware for the application. "

The main cause of pressure drop are the long lines of 1/2 inch copper tube buried in the slab. I notice no difference because of the valve. The accessible piping has been replaced by 3/4 inch. The main service pipe is 3/4 inch.

I have a similar, but much more expensive, valve (Lawler) in my darkroom that holds +|- 1/2 degree provided I draw at least 1/2 gallon a minute. It has a big knob so I can adjust the temperature anywhere between 65F and 105F, and a 3-inch temperature gauge so I can set it to the temperature I want. The big problem I have with valves of this type is that the regulate very poorly at very low flow rates. Sort of having a mod-con. You do not want an oversized boiler. You do not want an oversized valve.

Looking at the Caleffi catalog of these kinds of valve, the 5213 is the only one with scald protection in it. And their 521 series some of you suggest I use do not have it, and require a much higher minimum flow (1.3 gallons per minute instead of 1/2 gallon per minute). So if I ran just a shower, it would not be in the regulating range. My shower head is low flow, and can be adjusted for even lower flow. My kithen sink and bathroom both have low flow fixtures.

Installing a point of use valve in the shower would require removing my granite counter tops in my kitchen so I could remove some of the cabinets, so I could chop through the wall to install the thing. If I tried to go through from the bathroom, I would have to remove the tub and all the tiles on the wall. No way I could afford to do that. Chances are there are no good tile contractors around here.

Jean-David Beyer

"This string started because there was a problem with temperature control with the valve he used. "

Actually no problem with the valve I used. I notice my indirect has wide limits (15F), so the tank supplies between 140F and 155F according to the thermometer at the input to the valve. Yet whatever it is, the valve puts out between 120F and 121F according to the thermometer at the output of the valve.

STEVEusaPA

Geez. I only asked the question out of my own curiosity, based on my attendance of the webinar Hot Rod mentioned, and my constant reading of Idronics. But it looks like we got some great information out of it-which is always a good thing.

icesailor

@SteveusaPA:

STEVEusaPA said:

Geez. I only asked the question out of my own curiosity, based on my attendance of the webinar Hot Rod mentioned, and my constant reading of Idronics. But it looks like we got some great information out of it-which is always a good thing.

There is no such thing as a stupid question. Only ones not asked. We all learn from the questions and answers of others.

You can't not learn on HH.com if you just read the questions and the answers. It can't be done. Or else, you're not paying attention.