Why I like Thermostatically controlled Shower Valves

Whether you have an old fashioned two-handle valve or a more modern single-handle one, it is just mixing hot and cold water in various ratios, and the outlet temperature of your mix is entirely dependent on both the volume of both the hot and cold supplies, and their current temperature. Take this example: supply hot = 120-degrees, supply cold 70-degrees (say it's in the summer). If you mixed equal amounts of 120 and 70 degree water, you'd just average them to get 95-degree outlet temperature. To get a hotter output, you'd have to reduce how much cold you used, and cooler, vice-versa. Now, take that same scenario in the middle of winter when the incoming cold water is now 40-degrees. Mix those two together, and the average is 80-degrees. To get it warmer like it was in the summer, you'd need to reduce the cold a lot more than you did in the summer. On a two-handle valve, that means just adjusting the cold a little bit. On a single handle valve, that mean rotating the valve more towards the hot side. Note, if you properly setup that single handle valve, and say you did it in the summer, you'd have set the limit for how hot it could get. If it's now in the winter, that might not be hot enough. Done in the winter, the maximum hot might be way too hot when summer arrives and the cold water temperatures are much higher. So, from a safety standpoint, especially with young children or older people whose skin is thinner, that can pose a scald/burn hazard. Neither of these two choices can solve that problem. Then, take the situation where you're approaching the end of your tank's hot supply...the outlet hot temperature will slowly cool off, and to maintain your desired outlet temperature, you will have to regularly adjust the valve to give you more hot water into the mix. Depending on where the limit stop is set, while it might be fine when the tank is full, you may never be able to get it as hot as you'd like as the tank is nearly the end since you've limited the maximum amount of hot water into the mix.

Now, take a modern thermostatically controlled valve. When installing them, you still should calibrate it so when it says say 105-degrees, the outlet water actually is that temperature. But, most modern ones can automatically adjust the mix of hot and cold to KEEP the temperature the same, regardless of the inlet temperatures of either the hot OR cold! Even as the tank is being depleted and the tank's outlet is cooling off, the thermostatically controlled valve will just keep adding more hot and turning down the cold in the mix, all by itself. Now, they're not magic, and can't make hot water, but even if the outlet of the WH is reaching your desired temperature, you may not notice because the valve has automatically adjusted the mix to remain at a constant outlet temperature you have set. On the one I have, I only adjust it summer/winter to accommodate the air temperature in the room...making the mix cooler in the summer than the winter so essentially, what hits me ends up near the same temperature.

So, consider this tech when specifying your new shower valve.

 

Thanks for sharing, I found this pretty interesting

 

They should be a requirement.

 

I didn't know much about these at all and I found this really interesting thanks alot

 

I would expect to hear that from some one in California. That is the one state where everything causes cancer.

Don't mess with Texas. We are old school and are lucky to have hot water.

Spoiled comes to mind, While thinking about a wood stove and #3 wash tub.

 

Any feedback on the long term reliability of thermostatic valves?

 

Mine was installed in 2005 and still going strong. I did need to replace the volume control, but not the thermostatic control (yet). They are more expensive, but a nice hot shower is a luxury especially if you don't have to deal with the temperature changing...once you get it where you want, it's there (well, you might have to move it back if someone else moves it!). Or if moved, you know exactly where it needs to be reset. Mine is a Grohe...I do not have experience with others.

 

One thing that I learned recently is that, at least in some designs, a thermostatically controlled valve can flow a significantly larger volume than a pressure balanced valve. Look at it this way...when a pressure balance valve experiences a drop in pressure from one side, it drops the volume from the other so that the balance remains the same, maintaining the temperature. With a thermostatically controlled valve, it runs the hot at full most of the time, and only adjusts the cold to volume up or down to keep the temperature the same. So, the hot volume always remains essentially at full, or has the potential to be full until you select a much cooler output. That may not be an issue except when you are trying to run numerous jets. As a side benefit, the temperature is a bit more consistent, too.

 

I am going to add a shower into my 1/2 bath in the near future. At present I also have one full bath with the old style 3 handle valve setup. I have a vintage ELM Aquastar gas tankless gas water heater installed for hot water

When I take a shower with the 3 valve setup, I note that the cold valve is only set to a trickle for a comfortable shower temperature. This is February, so cold water is about as cold as it gets during the year.

Pressure balanced valves are commonly used these days, but I have my doubts about how well they perform with a tankless water heater. There are a lot of technical reasons for this performance issue.

I have decided to go the more expensive way and I will install a thermostatically controlled shower valve in the new shower. From what I can tell, a thermostatic valve will perform similar to the 3 handle valve in that an amount of cold water will be added to the hot water in order to maintain a constant temperature. Set the valves mechanical high temperature limit, and that should be it as far as safety is concerned as well as code requirements.

I think that I will go Delta. The in wall valve body can be used for both pressure balanced and thermostatic valves. Temperature control handle plus volume control handle.

My general thinking is if you have a tankless water heater, a thermostatically controlled water valve is the best way to go regardless of the additional cost. Am I wrong?

 

I made and still make a fantastic living being an expert witness and 97% of my cases are scalding

Thankfully America is blessed with a society of "victims" where no one has to accept personal responsibility

Child scalded in a tub has to be the landlords fault .. Water not hot enough to kill bacteria must be the installing plumbers fault for having the water too cold to kill bacteria

I had a great time about 16 years ago when I testified in court the water temperature was too hot as it was over 130 Deg F .

A few months later same court house different case I was testifying how the water was too cold as it was under 160 Def F

Tthe judge said she remembered me testifying a few months earlier and called for a 15 minute recess and I had to meet her in her chambers with a court officer following us.

When I was in her chambers she asked if I knew what perjury was and I said yes but I would never perjure myself

So she reminded me of the other case and I said well your honor as an expert I cannot rely on just one code and even in the same plumbing codes there are exceptions to most rules.

I then explained that because it is mixed use building the showers must be limited to 125 def F but the restaurants dishwasher has to have a rinse of 160 -180 deg F in lieu of chemicals for sterilization

The restaurant did not boost their water temperature and relied on the same hot water the building was using

So when I testified a few months ago about the scalding of the child I was stating what a shower temperature SHALL BE

So the restaurant hired a non licensed plumber to lower the water temperature and someone got deathly sick from botulism as the dishwasher hot water was under the board of health and NYC plumbing code guide lines

The judge then asked me what could be done to meet both code criteria . I said great question your honor

I said fist off having a licensed master plumber do the the following

1- Increase the temperature to 160 to kill bacteria in the tank (HW)

2- Install a quality tempering valve such as a Holby to bring the temperature to a safer temperature

3- Use one line from the tank as dedicated to the kitchen

4- have either a pressure or temperature or a combination of both installed for the showers and possibly for the other faucets

5- If there are children or the elderly present use a point of use tempering valve is highly recommended

The judge smiled and said I was walking a very thin line but let my testony stand

For this I was paid over $12,600 and picked up a few new accounts

 

I'm really a two handle(or three for tub shower) guy myself.
As an example, I had a case where the CU lines had a lot of calcium that broke lose.
Got an old Price Pfister valve and modified by putting a barb connector on the valve.
Ran a hose from the barb to the tub drain. Turned on the water and was able to easily
flush the lines.
Try doing that with a thermostatically controlled shower valve.
They also work till they don't.
Was in a hotel one time and the valve failed. Got all hot water and had to come out through
the shower curtain REAL QUICK!
Give me a two handled valve any day.

My2Cents.

 

If you "really like a two handle" then why not consider Thermostatic Valves

Thermostatic valves have two handles: one controlling the volume, one for the water temperature. This is because thermostatic valves react to the temperature, not the pressure of the water. With this valve, you can change the flow volume without affecting the temperature, which makes conservation easy: just turn down the flow while shampooing or shaving! This is all possible due to a wax element inside the valve that expands or contracts in reaction to heat. When water exceeds the maximum set temperature, the element expands to reduce the flow of hot water, and allow more cold into the mix. Should either hot or cold supply fail, the valve will close off flow from the other side. The advantage with thermostatic valves is the direct control over output temperature; while your water heater can be set to 140° F to protect against bacterial contamination, the water coming out of your shower head can always be 100° F (a maximum output temperature is set on the valve).

Again it is the unknowing who dabble in plumbing who put people in risk

This is why the Lord created "expert witnesses" to go after those who have little or no knowledge of all the safe options that are available to protect the public from unknowing installers

Below is a child who burned because the handyman installed a non code approved 2 handle shower body . This case will never go to court after I sent in my report

 

Here is the results of a 2 valve shower valve that offered no anti scald protection .

 

Yeah it's dangerous, and that's why by next year in NYC, it will be required that a licensed plumber be present to turn on the water and adjust the temperature each time a tenant showers. In older buildings without a thermostatic, the plumber must remain in the bathroom, blindfolded, until the tenant has completed the shower and fully dried off.

 

Not to get in a debate, but a little "Common Sense" goes a long way.
One needs to use what is above their neckline for more than a hat rack.

If -- or -- mostly likely when-- a Thermostatic Valve fails you're back to the same issue of manually regulating the water. I don't know what the MTBF (corrected from MBTF as typo) rating is for these units but at
some point failure. About year ago had a similar item on my stove -- yes stoves also use bi-metal sensors to monitor the burner temperature -- quit. Gave good service for 20-25 years though.

Not to take away or demean you in any way, but for every expert "For" there is an expert "Against".
Usually, there is some industry group behind "the expert" pushing their product as the next best thing since sliced bread -- OR -- some attorney who sees a big pay day and has more resources then the opposition to pay for expert testimony.

That said -- valve probably can't hurt, may help.

 

More TRUTH is said in jest

About your remark

"Yeah it's dangerous, and that's why by next year in NYC, it will be required that a licensed plumber be present to turn on the water and adjust the temperature each time a tenant showers"

Your not too far off mark as part of my contract is to go back TWICE a year to re adjust the setting for the summer and winter to 106- 108 deg F

This is for a 27 story co op that has over 768 shower body's I will be replacing

Think about it twice a year 768+ shower body's being adjusted @$80 each to allow for temperature fluctuations during the summer and winter .

Five (5) of the board members are lawyers and they are the ones who decided it is cheaper to hire a LMP then have one lawsuit because of personal injury ... here are many children and elderly living there

If the handymen touches the shower valves all warranties are void and they have the liability of any legal action


Sewer cleaning actually NETS more but when your older you can appreciate being an expert as it requires no physical work other then driving to the site.

The more lax the building owners are and the more non licensed idiots do the installations, master plumbers can reap amazing compensation especially if they charge knowing what they are worth

I was told when I was given the case where two toddlers died I could expect over $250,000 for my appearance at depositions and going to court court not counting the funding I already received .

https://video.search.yahoo.com/sear...=d6181e025dff4ca3145b8cd93530649a&action=view

As long unscrupulous landlords and DIY people are out there along with non formally educated plumbers who screw up there is a gold mine for those who are qualified to be an expert

Not all cases involve someone getting hurt or killed some are just testifying against non licensed people dabbling in a licensed profession for example boiler installations or lack of qualified inspections of heating , plumbing , fire suppression systems

One of my bigger accounts was the postal service where I did all the low pressure boiler and unfired pressure vessel inspections even as far as Hicksville LI main post office

$350 per boiler twice a year internal and external Hicksville was a lot more because of traveling time and it failed the first external inspection on one boiler so I had to go back and reinspect them

The reason I gave up the post offices

I had 138 boilers just in the Bronx ,and had Manhattan, Brooklyn, Staten Island and LI and I did not trust my employees to do a proper inspection and it was physically impossible to do a bi yearly inspections of all these boilers and pressure vessels hydrostatic pressure testing and safety valve testing twice a year

The town of Lawrence LI I took a master plumbers test (took almost 20 minutes to pass) and was able to go there for one day at a small shopping center to inspect 7 roof drains that someone installed .

The owner of the property paid me $7,000 to send in a 4 page report as to why the installation was faulty .. A computer store was flooded out and the landlord was looking for to get out from being suit

The reason I took the took test was to show credibility of being locally licensed so if I had to appear in court I would show I knew their local code as NYC codes were to much more stringent for the town

With more lawsuits coming down the pike stricter codes will be required to protect people from themselves as the invaders from 4th world countries never heard about hot water it would seem

I am now working for 3 nursing homes redoing the domestic hot water supply on a T&M basis and I have people working 7 days a week and at night for shutdowns

A lot people do not realize what plumbing encoumpases .

Also being an ex stationary engineer helps with knowing the inner workings of commercial buildings as I was a certified stationary engineer at 90 Church street so I know for personal experience how moons are lawsuits looking to happen this was one of the deciding factors that convinced me to work as an expert

We live in a society where everyone is a victim and expects someone else to take care of them from birth until death with the give me I am entitled mentality and personal responsibility is unheard of for people under 40

Free food (stamps) free housing (section 8) free medical ,free college , stay home and get paid to breed etc.

 

"
Not to take away or demean you in any way, but for every expert "For" there is an expert "Against".
Usually, there is some industry group behind "the expert" pushing their product as the next best thing since sliced bread -- OR -- some attorney who sees a big pay day and has more resources then the opposition to pay for expert testimony.."

Right on

Before I take on a case I always ask "which side and I on"

Reason being I am giving my "opinion" which like a belly button everyone has one

I sometimes work for insurance companies or building owners but unfortunately it is cheaper to settle out of court then go before a jury . I

n America the new way of thinking is "your guilty until proven innocent "so sad as this is why insurance rates have skyrocketed

 

My wife was a certified legal assistant and for 25 years she worked in defense with two different companies & attorneys over those years. Defense means they represented the insurance companies whereby their client was being sued. The worst part of it was when people lied about injuries. Twice over those years two were arrested for fraud and contempt. One was after the plaintiff won the case. What I surmised over the years is attorneys will sue over anything and everyone in eye site and let the judge decide who will be allowed in the law suite. When cases she worked on went to court, her attorney(s) almost always won because they knew there were false statements and could win the case. Most of the time it was out of court settlement because as you stated, cost to go to court and for "expert" witnesses.

 

A Curb box in Brooklyn is walked over by several million people a year .. A law firm called my office asking who is responsible for the curb box .

I told them my fee is $1,400 to give them a report and after their check clears I will furnish them with all the information they require

The next day I received the check and the following week I send them a copy of the sections of the NYC and DEP plumbing code about who is responsible for the box and who must maintain it in a safe manner

Seems Millions of people walk on this curb box and only one person in the past 42 years since it was installed slipped and broke her ankle

The box was 1/8 " the below the sidewalk and this was considered a tripping hazard. The firm that hired me needed to know who they should go after

I work for over 37 law firms and only a a dozen times did I actually have to go to court to testify

This was settled out of court for $160,000

In law your wife should know "there is no right or wrong" it is a question of win or lose

Ted Kennedy is a winner in spite of killing Mary Jo, Wild BIll Clinton and HELLery won with a get out of jail free card

Mike Bloomberg WON even though NYC voted fro two term limits he managed to stay in office 3 terms

Creep Joe is a born winner as anyone else would be considered a threat to women and sued for sexual harassment

Anthony little Weiner is a Loser as he was thrown to the wolves so HELLery can be with his wife

If your a drunk driver and kill someone in Massachusetts do you think you would be elected to the senate?

Cop killers are supposed to be executed or spend their life in prison but they are given a get out of jail free card

The law is as corrupt as our politicians

As I stated once in Supreme court in Manhattan "America is blessed with the best politicians money can buy"