FALSE CLAIM! - Thermostatic Mixing Valves (Cash ACME Tank Booster) will *not* double hot water!

[@jsncrso]

I'm an engineer who's installed hundreds of these things and you couldn't possibly be more wrong. They absolutely do work and they work well. Going from 120F to 150F gives you 42% more heat capacity in terms of BTUs in a standard 40 gallon water heater. What you are completely missing is that the hotter the water in the tank, the less hot water flow is needed to reach your 120F setpoint. For a 2.5 GPM shower fixture, if you have your water heater set at 120F and you want your shower temperature to also be 120F, you will be pulling 2.5GPM out of your water heater. If you have your water heater set at 150F and want your shower temp to be 120F, then the TMV will pull about 1.8GPM from your water heater and the other 0.7GPM from the cold side (depending on the cold water temp), giving you 120F water at 2.5GPM. So yes, drawing 1.8GPM vs 2.5GPM from your water heater will absolutely increase your hot water capacity. You may have a defective unit which does happen (the check valves can get stuck open on them with debris)

[@kentcan]

Sorry friend, I'm an accountant--not an engineer--but I can tell you that you're missing one-third of your equation! :) You neglected to mention the cold water added at the shower. If your showerhead output is 2.5 gpm at 105º, the amount of cold water needed to cool the º150 water is going to be the same whether or not your system has a TMV. A TMV doesn't change the laws of thermodynamics. Without a TMV you're adding all the cold water at the head; with one you're adding some of it at the tank. If we wanted to get all scientific we would use the formula Q = M X C X ΔT , but let's keep the concept simple for now. :) Hypothetically... Without TMV: 1.3gpm hot [at 150º] + 1.2gpm cold [60º] at the head = 2.5gpm at 105º With TMV: 1.3gpm hot [at 150º] + 0.6gmp cold [60º] at the TMV + 0.6gpm cold [60º] at the head = 2.5gpm at 105º

[@patricklynch4764]

@@kentcan I think that your well thought out equations prove that there is no free lunch! No magic works against the absolute limits of conservation of energy. True that. But I'd like to respectfully offer that your equations aren't quite following what jsncrso is trying to say. His (her?) starting point is at a much higher point of stored potential energy. Moving the water heater set point to 150 from 120 does this. Thus giving you "more" hot water from the extra stored heat, which is the gist of the claim on the box. Is it double? Hmm, maybe only in a lab! But certainly more. The quibble could be that standing (tank) loss at 150 is more than at 120, but modern tanks are more insulated than before, so less of a concern. For example, the Rheem Proterra is both well insulated and has a built in mixing valve to take advantage of this approach. Competing with tankless, this appears to be the direction domestic water heating is evolving to gain overall energy efficiency.... larger very well insulated tanks heated to higher temperatures with slow 120v heat pump + mixing valve vs current smaller less insulated 240v electric resistance heated to 120. Happy well heated New Year! :)

[@Syth_L0rd]

@@kentcan I think the part you are missing from your equations, is that tanks have a recovery rate, how long it takes the tank to warm up the incoming cold water and bring it up to the set point. The way this boosts available hot water, is that by having the tank set to 140+, the water heater is able to maintain the hot water inside the tank at a higher temperature for longer, since it takes more cold water to cool down hot water at 140+F than 120F you have more "capacity". You are too focused at what's happening at the shower head, rather than inside the tank. Hopefully that makes sense.

[@artdeco5464]

@@Syth_L0rd Nah... he's too busy whining to do basic math...

[@goproheronomablackedition7899]

Interesting I would add the potential heat loss in the pipes after you stop the flow - better to have it lower temperature running in the pipes. In France it is a mandatory to have it if you are using pex or multilayer pipes just to protect the system 😢

[@danielmarra1555]

I know what your problem is. You were accustomed at having 140° water in your home. Now with the thermostatic mixing valve, it limits your water temperature to 120, which is the normal safe temperature. The way the mixing valve works is you set your hot water heater more than 120, for example 140, and then when the cold water is added it goes back to 120. So if you wanna go back to 140° water you need to remove the mixing valve because it is set at 120° maximum to prevent scolding. The purpose of a mixing valve is to give you more volume and it’s also a safety feature which I don’t think you understood. These mixing valves work efficiently but you need to keep your heater at a higher temperature so you can have a constant 120° water which is safe. You on the other hand, normally have your water heater set at 140°, which is unsafe.

[@SamMcWhannel]

It is true that you mix the water at the point of use anyway, but that isn't the intent of how a TMV can increase hot water capacity. With a TMV you can store water at up to 180F in the tank (or as high as your tank can be set). Typically no one would set their tank above 140F for risk of burns, with a TMV you can set it as high as you can. The higher the tank temperature, the higher the heat capacity with the same volume of stored hot water since you then mix substantially more cold water and draw less hot water to attain the same temperature at the bath/shower. If you do not increase the tank temperature when you install a TMV though, then you will see no capacity gain because as you stated you are mixing the same amount of water as before.

[@dus10dnd]

There are whole house TMVs, as well... not just at the point of use.

[@SamMcWhannel]

@@dus10dnd Yeah that's what I was referring to, the video doesn't seem to understand the purpose/use case of that whole house TMV he's showing.

[@cmfrancis1]

You need to crank the temperature in the tank way way up for a mixing valve to work.

[@BrianMiller-hc1kl]

This is the key

[@bigjeep2195]

Exactly, this guy is missing that part.

[@dus10dnd]

How could it possibly double the hot water? If the normal temp is 120F and you increase to 140F or 150F, you're only increasing the temperature by 20-25%. That's all using a TMV that will reduce the temperature back down to 120F will gain you.... 20-25%. That being said, they do work. Did you not increase the temperature of your hot water heater??? That is the entire point of this. The TMX won't do anything if you don't increase the temperature. You dramatically increase the temperature and you use less of it. The point isn't that you can control the temperature at point of use... it is that it is dangerous to have 150F water at the point of use. Yes, if you use your brain and never accidentally pump the handle, you can use handle it yourself at your shower or at your clothes washer. But, when you have to rush your children, or yourself, to the hospital for a burn, that wouldn't be good. It seems that you just don't understand how this is supposed to work.

[@miller6698]

7 people need a larger hot water heater than 40 gallons

[@seanmcne]

Think of your water heater as a battery. It should be set to 120, now you add a mixing valve or regulator and raise your water heater to 150. That same tank now holds more energy than it did before and the mixing valve ensures the max amount exiting the tap is 120 (which is what it should have been before) so now you have a 30 degree buffer. I have one of these I don’t get double but my 50gal water heater now works the same as an 80gal water heater and I didn’t need to get an 80 gal water heater.

[@MiklaDfar]

LOL!!!!! Oh my...please stop trying to be an Engineer. As a Mechanical Engineer, I can tell you that you are wrong. Anyone looking to buy one of these, IGNORE THIS VIDEO!

[@NomoWorries-j3c]

Ok.. Normally you’re tank is set at 120 for scalding reasons….so it sounds like you’re use to 140 coming out of the taps… put this on and you have 120 out the taps… it’s working… just not to you're expectation…. You’re confounding the results with your unrealistic expectations of still getting 140 out of the taps… your analysis is not correct. And just because you have a phone and can make a video doesn’t make you correct on your analysis.

[@tylercornett2022]

I mean, i can respect that --for your specific use case-- this device didn't meet your expectations. You are wildly into speculative fiction on most of your "points" though. The math of a thermostatic mixing valve checks out just fine as long as the delta between your initial water heater temp setting and current temp setting is high enough. The real increased capacity of hot water is directly proportional to that temperature delta... Because it's a proportioning valve lol. Anyway, your tank is undersized. Cheers.

[@LearnPlumbing]

I posted a video that absolutely proves it does double your available hot water. I have one on my own home. Its wonderful.

[@Mr.Morris-og9hw]

Dude, you have your facts wrong. You dont look at it as how much hot water usage, it is the amount of "energy" consumption that is needed to satisfy your needs. 😅😂

[@PENDER-OIF1]

That expansion tank needs to be mounted differently it’s doing nothing mounted that way

[@dmmsr]

So first your water heater by code should only be set at 120 degrees for scalding reasons not 140. You are wrong. So this is when I stopped listening to you. No one's water heater is set at that unless they turned it up themselves. This booster has no heating element and does not advertise it. It is what you said it mixes the water. This is a thermostatic mixing valve to increase your hot water usage. Third you need to increase your water heaters thermostat to 160 - 180 to get the proper usage of this. Fourth you must've hired a handyman because it is not code to have less than 18" of copper coming off your water heater and must have a bonding wire. And please dont say youre going to teach someone how a water heater works when the only explanation you say is cold water comes in and heats it and sends it out. That is no way an explanation of how it functions. Sounds like this is how a toaster works,you put bread in push the lever down and it comes out toast. Wow! So these do work. Again water heaters are set at 120 max for residential use. You install th mixing valve and increase the thermostat to 160-180. Then reduce the temp coming out down to 118-120. This is where most customers feel comfortable. Amything lower they do not typically like. Then as yo use the hot water, yes the cold water mixes enough to reduce lets say 180 down to 120. Now you have an extended point of use where you can take a 40 gallon water heater and increase it to now being compared to a larger capacity of 60 to 75 gallon tank. These wirk excellent and especially since the government did away with 80 gallon electric.

[@kentcan]

Two things two say to you, one to everyone else. 1. Plumbing code is state- and county-specific, so unless you work in my state and county, you're bringing more arrogance to the conversation than true knowledge. 2. I laid out my case pretty well in the video and then even more so in the comments. Saying "it works" or "you're wrong" does nothing to refute my claims. 3. To everyone else, notice how all the plumbers in these comments who are mad at me for exposing this high-profit device! That should tell you something right there! Watch their videos, watch my videos, do your research, and make your decision. I for one won't get upset with you if you take a position that disagrees with mine. But then...that's because I've got nothing to lose. 😄

[@frankb1]

I'm not persuaded. With the valve you are using less water from the tank which means less cold water is being added to the tank which means the temperature in the tank is higher. I'm not claiming the valve will double your hot water but you will certainly have more hot water available.

[@christinsley3736]

too many people/showers for an electric water heater to recover fast enough, even at 50 gallons, has nothing to do with the valve

[@davidunderwood4341]

From what I'm understanding is this will supply more hot water simply because the mixing valve allows you to crank the tank temp as high as you want. With that said, you're compromising having hot water for longer, but putting a shorter life on your tank. Is my analysis correct?

[@rugershooter5268]

If if if this was installed correctly the water going to your fixtures hot water valve will be exactly the same as it was before installation......the user would notice no difference whatsoever If if if your water heater was set at 120* before installation, then after installation it should be turned up to 140* and the device set at 120*....what's going to your fixtures is exactly the same Most likely you had your water heater set at 140* and your professional installer decided you needed 120 going to your fixtures, when it should have been set at 140* and the water heater turned up to guess 160* Set your device to same temp as your water heater, the increase temp on water heater This device is NOT intended to save you money, its purpose is to make your hot water last longer, and it certainly will do that if it is installed correctly

[@williamemmons8816]

Hysterical! Please research, your assumptions are not based on all items working to their design function. Did you diagnose tank function, mixing valve element function

[@Drowe218]

Disable the valve, run the shower until it runs cold, time it. Then do it with the valve. I have one and it added a significant amount if hot water time. Thats the purpose, not to save you water. Technology connections did a video on hot water heaters and run it as hot as you need to get the capacity that your family needs

[@TRexLuthor]

It’s not a scam. This video is fake news. I have the same mixing valve. I can confirm it works. Before we always had arguments about not having enough hot water before work. With 2 suites in the house that has a single small tank for both units, with 2x washer dryers and 2x dishwashers and up to 5 people in total, we now have never had a problem after installing the valve. Once both the tank and the valve itself was adjusted properly. The highest temperature is reduced, but we get hot water for much longer.

[@TRexLuthor]

PS the mixing valve comes with an Allen key to adjust the amount of cold water that comes in. For anyone else interested. Keep in mind if the tank’s settings and the valve’s settings are not set properly for your home’s requirements you may not get the result you expected.

[@DoeyPP]

This has to be one stupid idea.

[@wyldanimal2]

You obviously don't understand how it works. to Prevent Scalding without the Mixing valve, you would have to set your Hot water Heater to 120 or less. So then you have a limited Supply of 120 degree hot water. Call it 30 gallons. With the Added Mixing Valve, you can Now set your Hot water Heater to Higher than 120. Maybe set it at 150. So the Tank now has the Same 30 Gallon Limited amount of Hot water, but at a Much Higher Temperature 150. To Prevent Scalding, the Valve mixes in Cold Water to reduce the 150 degree hot water down to 120. This gives you a Much larger Volume of 120 degree Water, than what the Tank Alone could produce. Instead of only 30 gallons at 120, you will now have 50 gallons At 120. You're NOT saving on your Total Water usage, you are just Increasing the Volume of available HOT water from the Same Size Tank. The Cost is the Increase in Energy needed to Heat and Maintain the Tank from 120 to 150. Yes, there is an Increased energy cost.

[@kentcan]

You obviously don't understand how it works. As mentioned in the video and clarified in multiple comments now, the capacity was increased ONLY by turning up the hot water, NOT by adding the mixing valve. The mixing valve reduces scalding potential, yes. That was also made clear in the video. But if you're heating your water to 150º, it doesn't matter whether you mix the cold water at the tank (TMV) or at the tap; your total capacity is the same. So if you want 120º water coming out your showerhead, mix it wherever you want...it's drawing the same amount of 150º water out of the hot water heater either way. But my way--dropping the TMV--you're saving yourself $350 - $500. :D

[@kentcan]

I find it funny that after thousands of years of civilization, there is still a large segment of the population that can't tolerate having their preconceived notions questioned without getting all bent out of shape! 😄 I'm not going to reply to any more individual comments, but for the sake of those viewers wanting to learn about this topic, let's be clear: all claims below (or otherwise) that a TMV will increase your hot water *are based on the assumption you are going to turn up the heat on your hot water heater*! This little detail is not divulged in most TMV advertising, nor was it discussed by my plumber when he recommended and installed my Tank Booster. So sure--if you turn up your hot water heater, you're going to get more hot water. Duh! That's the case with or without a TMV! The TMV simply allows you to turn up the thermostat while delivering lower-temperature hot water to your outlets. So it IS a good safety device if you want to turn up your hot water to 140º or more. But that's not what this video is about. 🙂 TMVs do not increase hot water; only turning up your temperature will increase hot water capacity. This little detail is less efficient and more costly. It might work for your situation, and that's great...but let's be honest about what's actually happening. My family of seven had a 50-gallon hot water heater. We installed the TMV at the recommendation of our plumber, then a year later the water heater reached the end of its life and we installed a 55-gallon heater--the largest water heater we could find without going commercial. Commercial would be great, sure...but they are $3k+, so not feasible for most families. It was after I installed the new 55-gallon water heater and reattached the TMV that I realized the TMV wasn't really doing anything to increase our hot water capacity. If you need more hot water, turn up the temp or get a new heater. Don't waste your money on a TMV because it's not going to fix your problem. Only buy a TMV if you need to turn up your temperature and want to send lower-temp water to your taps.

[@jamesz1961]

One more thing is that this thing is easy to get clogged so that you feel the hot water pressure gone low if your water source is a well in your front yard. I am using the well water, and I want to get rid of it on my hot water tank. My house was built 2 years ago, but I have had it replaced once already because I still have had no idea how to clean it up and restore it into a normal working condition, though every 6 months I will have the tank flushed. And just for 7 months now after the replacement, I have found the hot water pressure gone low, again.

[@matthewhumphrey8128]

thanks