# Tempering Valve Siezing in restaurant



## solarman.net (Feb 2, 2009)

We have a situation at a Seafood Rest. wherein the hot water tempering valve loads up with white sediment on a regular basis. This is causing the tempering valve to sieze up and not deliver warm water to the rest room lavatories or kitchen hand sinks.

This is a typical large commercial kitchen with a water heating plant delivering 180'F water which is delivered to the commercial dishwasher and also to a tempering valve which mixes it with cold water to make 140'F water for the kitchen sinks and mop sinks. Some of the 140'F water is then further tempered through a second tempering valve to make 110'F warm water for hand washing.

There is a water softener which softens ONLY the water feeding the water heater and the tempering valves to mix with hot water. No soft cold water to anything in the building.

Both tempering valves have extensive sediment build up: However it appears to be only on the hot side.

There is no build up on faucets or the dishwasher.

The "sediment" is a white corrosion LIKE substance.......I say LIKE because it is not corrosion, the bronze valves or piping are not being eaten away, this white stuff is building up on the metalic parts of the devices.

Facts:
1.  Softener feeds only the water heaters and the tempering valves.
2. We have checked and the water is soft, also the PH of the water is neutral.
3. On the 140' to 110' tempering valve the cold side is clean and NO build up / hot side siezed up with stuff
4. The "sediment" is building up on the smaller metalic parts. Springs, plungers, gears.....NOT the bronze housings or piping.
5. The water heaters are gas fired....one 100 gallon commercial with a 100 gallon storage tank & one 180' booster heater for the dishwasher.
6. It only takes 4 to 6 months to completely sieze up the entire valving system.

Any thoughts?

Until we resolve this we will be married to a few service calls per year to clean out these valves.. While service calls are good, I'm sure they will tire of the same recurring problem. Would like to have an answer for this client soon


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## user4 (Jun 12, 2008)

Sounds like scale being formed by calcium particles in the water that bond together when the water is heated. Try installing a sediment filter on the hot side before it goes into the tempering valve.


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## Protech (Sep 22, 2008)

You could also try using one of those electrolysis based de-mineralizers. They work like a water softener accept they use no chemicals and therefore add nothing to the water. They run a DC charge thru a titanium electrode(anode) and the calcium salts in the water become de-ionized after reacting with the anode. The calcium ions are still in the water but since they are no longer charged they will not precipitate out of solution and bond to solid surfaces in hot water systems.

You can get them from Integrity Sales & Marketing, Inc. They are in Mulberry Fl. (863) 425-3900.

I hope that helps.


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## ILPlumber (Jun 17, 2008)

What kind of valve was it?

I knoe Leonard has an extensive maintence plan for their valves. I believe it something crazy like disassembly and cleaning evry 30 or 60 days. I can't recall. They have problems with sediment build-up preventing valve function.


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## WestCoastPlumber (Jun 17, 2008)

solarman.net said:


> We have a situation at a Seafood Rest. wherein the hot water tempering valve loads up with white sediment on a regular basis. This is causing the tempering valve to sieze up and not deliver warm water to the rest room lavatories or kitchen hand sinks.
> 
> This is a typical large commercial kitchen with a water heating plant delivering 180'F water which is delivered to the commercial dishwasher and also to a tempering valve which mixes it with cold water to make 140'F water for the kitchen sinks and mop sinks. Some of the 140'F water is then further tempered through a second tempering valve to make 110'F warm water for hand washing.
> 
> ...


 


are you sure it isn't a dip tube? I have had dip tubes do this all the time.


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## user4 (Jun 12, 2008)

WestCoastPlumber said:


> are you sure it isn't a dip tube? I have had dip tubes do this all the time.


Most commercial water heaters don't have dip tubes, the cold inlet is on the bottom of the tank.


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## Ron (Jun 12, 2008)

Killertoiletspider said:


> Most commercial water heaters don't have dip tubes, the cold inlet is on the bottom of the tank.


The one I did not long ago you had an option top of side inlet, we connected to top, so it had to have a dip tube in it.


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## WestCoastPlumber (Jun 17, 2008)

Ron The Plumber said:


> The one I did not long ago you had an option top of side inlet, we connected to top, so it had to have a dip tube in it.


 



Thank you, most commercial water heaters here are piped from the top. There are those that are piped fromt he side, but I mean't one with a dip tube on it.


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## user4 (Jun 12, 2008)

Ron The Plumber said:


> The one I did not long ago you had an option top of side inlet, we connected to top, so it had to have a dip tube in it.





WestCoastPlumber said:


> Thank you, most commercial water heaters here are piped from the top. There are those that are piped fromt he side, but I mean't one with a dip tube on it.



I stand corrected, I have never seen that, perhaps it's a west coast thing. Here if you want a top inlet commercial heater you have to order it, and wait for it to be built.


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## I'mYourTourGuide (Jun 23, 2008)

Killertoiletspider said:


> Sounds like scale being formed by calcium particles in the water that bond together when the water is heated. Try installing a sediment filter on the hot side before it goes into the tempering valve.


I agree with KTS on this. 

I had the same trouble at a local jail.

ACORN Recessed Box with Powers 420 and check stops were completely dobbed just about it.

Green scale build-up was the culprit.


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## I'mYourTourGuide (Jun 23, 2008)

WestCoastPlumber said:


> Thank you, most commercial water heaters here are piped from the top. There are those that are piped fromt he side, but I mean't one with a dip tube on it.



I hate side-inlet W/Hs.

Can you say "drain down"?


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## ILPlumber (Jun 17, 2008)

Speaking of side inlet Wh's. I learned an important lesson as a young journeyman. Put the valves and unions above the top of WH's that are piped tight together in a row. 

That way they can be easily removed when the service plumber follows behind. 

Don't forget to do the same thing on the gas and pvc intake and exhaust.


We had to change one I had piped a couple years earlier. I had to cut everything to get it out. As well as having to shut the building down to unscrew the gas drop.


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## ASUPERTECH (Jun 22, 2008)

solarman.net said:


> We have a situation at a Seafood Rest. wherein the hot water tempering valve loads up with white sediment on a regular basis. This is causing the tempering valve to sieze up and not deliver warm water to the rest room lavatories or kitchen hand sinks.
> 
> This is a typical large commercial kitchen with a water heating plant delivering 180'F water which is delivered to the commercial dishwasher and also to a tempering valve which mixes it with cold water to make 140'F water for the kitchen sinks and mop sinks. Some of the 140'F water is then further tempered through a second tempering valve to make 110'F warm water for hand washing.
> 
> ...


 Why not a repipe?
"T" in and pipe the soft water, currently only feeding the WH to the cold side of the mixing valve..If you add one drop of hard water to soft water you now have hard water. you could also install isolation valves & boiler drains at all 3 pts on the mixing valve, and then using either one of those tankless flush kits or your own home made version to flush out the valve w/ out dissassembly.


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## plumber1a (Jan 3, 2009)

This is scale build up, use a good commercial scale inhibitor prior to the tempering valve.


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## solarman.net (Feb 2, 2009)

Killertoiletspider said:


> Sounds like scale being formed by calcium particles in the water that bond together when the water is heated. Try installing a sediment filter on the hot side before it goes into the tempering valve.


Good idea... Feed water is 180'F, concerned about comprimising filter housing or element.


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## plumber1a (Jan 3, 2009)

Make sure it's rated for the application.


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## gladerunner (Jan 24, 2009)

I vote for dip tube also. Do you have room for a strainer before the mixer? Might make cleaning service call easier.


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## ASUPERTECH (Jun 22, 2008)

solarman.net said:


> Good idea... Feed water is 180'F, concerned about comprimising filter housing or element.


The hotter the water the faster you will draw out the minerals. Is all the water going through the mixing valve being treated? A filter will not do anything for mineral build up, the scale shield may help, but seems to me you already have everything you need on the job right now except pipe. Remeber to K.I.S.S. it, the more you add, the more there is to service/ repair/ replace.


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## Plumberman (Jul 7, 2008)

Killertoiletspider said:


> I stand corrected, I have never seen that, perhaps it's a west coast thing. Here if you want a top inlet commercial heater you have to order it, and wait for it to be built.


We have top and dual side down here, You have to buy 4 nipples and 4 caps for whatever side you dont use....


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## LIVBMI (Sep 12, 2008)

I Had The Same Problem With A Lenard Valve In A Hospital.
The Build Up Was On The Bi Metal Coil Keeping It From Moving.
I Washed It Out And Reinstalled It, Worked Like New. I Also Had A Water Softener On The 180 Line. The Only Build Up Was In The Bi Metal. I Think The They Should Use A Better Bi Metal. As Was Posted Earlier, Cleaning Every Six Month Will Do The Job.


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## Green Country (Mar 6, 2009)

The first thing that came to my mind is the soft water mixing with the harder water, and minerals are precipitating out of solution. Softening both sides would eliminate or reduce the precipitation.

The second thing that came to mind was the fact that I have no idea if mixing the two waters would cause this phenomenon. Sounds good though:thumbup:


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## gear junkie (Jun 20, 2008)

Bump....other thoughts?


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## Gettinit (May 9, 2012)

gear junkie said:


> Bump....other thoughts?


It is normal to have buildup, especially with hard water. Many valves need to be taken apart and cleaned on a regular basis. Some more frequently than others. I am too lazy to read the entire thread. Is there a particular valve or problem in question?


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## AndersenPlumbing (Jan 23, 2010)

What brand valve is it?


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## gear junkie (Jun 20, 2008)

Gettinit said:


> It is normal to have buildup, especially with hard water. Many valves need to be taken apart and cleaned on a regular basis. Some more frequently than others. I am too lazy to read the entire thread. Is there a particular valve or problem in question?


No but a resturant wants me to look into a problem on wedsday that has the exact same symptoms as the op.


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## Gettinit (May 9, 2012)

gear junkie said:


> No but a resturant wants me to look into a problem on wedsday that has the exact same symptoms as the op.


Best piece of advice I can give is do not take it apart until you have the gaskets and cartridge (if it uses one). If it has not been took out in a long time it is usually easier to just replace the cartridge and get then on a maintenance plan. It may be cheaper to replace it every once in awhile until they realize how long they will be shut down while you get parts. Also, if it is a cartridge there is a sleeve that slides in and out to supply your tempered water. Do not let that bad boy come out. It is a royal pain to get back in. A pair of needle nose pliers can help you get the sleeve out if stuck. Oh, a whole new valve may be cheaper than parts and scrap the brass. 

I know the above isn't a coherent thought, sorry.


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## plumberpro (Jan 1, 2013)

The symmons temp valve requires regular maitance and if hasn't been done in awhile it can be hard to get out of the valve body make sure you have new o rings you can clean the screen and balancing sleeve in a solution of diluted muratic acid were rubber gloves it will clean it like brand new use silicone grease on the new o rings and carefully push it in place till it is in all the way do not force or use the screws to draw it in then your good to go.

Sent from my iPhone using PlumbingZone


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