How to Pipe 2 Water Heaters in Tandem Water Heaters Now

[@dukeraul624]

How do the 90’s on one side and not on the other play into the balance?

[@charvakkarpe]

They don't, he did it wrong. He put the equal length pipe up top first, then realized the ports aren't equidistant and added the 90's. Should have just made the left horizontal run longer, it would affect the resistance less than the 90's.

[@scottishjeep]

Thx! This helped me double check what plumbers were saying. Will get it fixed.

[@LeighCassidy]

Thank you, What if both tanks are indirect off of a boiler? There is a large tub to fill and no other room in boiler room for a larger tank. I would like to work with what I have. Thank you.

[@tonyd3029]

Nice video, Thank you. on parallel hook up with two water heaters how important is to for all the piping be the same length? is there a max amount that the pipe length can varied in size? My out going hot side piping is about 13" different length. from one to other?

[@dwmcever]

This is exactly correct. The water heaters also need to be the exact same make and model and age. Also I would valve off each heater so it could be taken out of service

[@navyretired230]

I am not sure I totally agree. I have two water heaters. One is electric run 100% by solar PV. The other is a gas water heater. The Electric water heater is free to run since it is PV. The gas water heater only runs during peak water demand since the electric water heater feeds the gas water heater. Savings is about $400-$700 per year in utility bills since my electric is all provided by solar roof mounted PV cells

[@ethanku]

So you just pipe the hot of the electric in series to the cold input of the gas heater? I also have solar cells, but only one gas water heater right now. Anything else to consider when you did this?

[@rjohnsoneod]

I considered parallel and series but in series I would think that the first tank would work harder than the second as the second is maintaining the temp and the first tank will wear out faster. I am unsure if parallel is much better as one tank will always die before the other. It sounds like you have it hooked up that the second kicks in only when needed but I only have electic (no gas, no solar) and I think parallel would be best for our home. Like to see some pictures or even a video of your set up.

[@joeonortega3234]

Dope video 👍🏽 do they have to be that together? Could they be 20+ feet from each other?

[@roberthunter8573]

Awesome advice! Thank you

[@alucardwhite7524]

Thanks for confirmed information Sr. I just told a gentlemen that post a video the same thing i am A HVAC/R ENGINEER and he said tie both hot water lines directly and get the hot water from the cold water in let Lol not safe practice at all .Have a great day thank you

[@RVentura42]

I have solar panels and I am considering buying two hybrid heat pump water tanks. Connecting one to provide heat through baseboards and the other to provide hot water for faucets. Can this be done and is this a good idea?

[@PhoneSpecificationsUSA]

With this configuration, is it ok to shut off one hot water heater and run on only one while keeping the shut-off hot water in place? The reason why I am asking is in the event one of the hot heaters starts leaking. Would like to simply turn off the leaking hot water heater and run on only one.....? Thanks.

[@devathaphani]

I have this dual water heater set up and 1 expanaion. Can we run only one water heater and turn off other ?

[@wyleaziz5050]

Ray, You deserved a like and a subscription. Keep the knowledge flowing sir!

[@dano1234v]

What about expansion tanks? Thanks

[@mikealba1814]

Good video . Seem a few done wrongly as you mentioned but with a recirculating pump on the first (50 gal gas ) cold inlet . It didn’t last long bu worked well . Please tell me what the mixing valve Is there though?

[@seanobrien499]

each heater has its own dedicated breaker? Can I do this w/one 30 amp breaker and (2) 40 gallon tanks?

[@MrAlexVail]

Can I pipe a tankless water heater in tandem with a tank heater ?

[@smartasasackofhammer]

where does the expansion tank go

[@johnvines4875]

I have one that is on the ON and the other on IDLE, is that correct?

[@k2buildit]

You say equal vertical distance and horizontal. But u have fitting on one and not the other. Wouldn't that throw it off as even though total height is the same, the length is different?

[@ruiibanez]

where would you install a recirulator pump in this setup?

[@rdizzleoriginal]

Between the tank feed lines with a one way valve

[@joelt8915]

My wife wants us to look into getting a hybrid electric hot water heater. We have a standby tank and heat with oil. But with oil costs now above 5.19 a gallon. This fuel is quickly becoming too expensive. We are now heating the home with the fireplace. And wanted to see if there was a way to add another water heater in tandem but isolate one and choose one over the other. Essentially creating a redundancy. So when when energy source is too expensive we can jump to another?

[@reirei7667]

Can I use a 40 and 50 together

[@adventuresofkishir3754]

Hey @Water Heaters Now - example here - I see you have 2 tanks in the video left and right. Imagine mine is the RIGHT one - is it possible to run a pipe from that tank to another ROOM directly to a shower. Say - from 1 apartment to another, so my neighbor can get free hot water at the cost of ME paying for it? Because every time I turn my tank on vacation mode the water goes cold then my neighbor complains about not having hot water but they do when I turn it back on.

[@elmono3939]

It is not "wrong" to install two hot water heaters is series-type installation. It depends what presented situation requires. If you have two different size tanks, or gas and electric tanks, than series-type installation is perfectly OK, and preferable. In your example, you have two identical tanks, thus parallel-installation is way to go. Another thing is, your cold water pipe is not "equal" as you claim, as you have two elbows installed on old water side on the left heater. Those two elbows take away from water flow as they create additional friction slowing down water delivery, as opposed to straight run on the right tank, creating pressure in-balance in process. Thank you

[@tomdowling3994]

What is the best connector to use for transitioning from CPVC house piping to copper tubing at the water heater connections?

[@tonymc3817]

Sharkbite. Only if installed correctly.

[@grantparnes]

What if you don't really need 2 water heaters but you have 2 water heaters? Inlet water temp is 40 in northern Idaho. I feel, they did this like you said NOT to do it, to get the first heater from 40 to 90, and let the second heater get it from 90 to 125 or so. In THAT situation, is there some logic?

[@Jared_Albert]

Thank you

[@eshacooper8741]

Is this set up better than having 1 80 gallon? If so why?

[@Chris_In_Texas]

It depends on the burner size and 1st hour delivery rates. This setup he showed won't be the same because of the extra bends on both inlet and outlet. It will use more hot water from the tank on the right as it will have less resistance. That being said, if you have two 40 gal tanks each with 40K BTU and 1st hour rating of say 60 gallons, then if you have a single 80 gallon tank with 80K BTU heater and 1st hour rating of 120 gallons, effectively they would be the same, just with 2x the amount of leak points and maintenance to do to each tank vs the single tank. You just need the space for the 80 gal tank, and I would always prefer the single over twin tanks. If you have a hot water return loop you will have the exact same issue in that one tank could be preferred and the other one won't run near as much. So again single tank is better solution if you can do it.

[@kurtvonfricken6829]

@@Chris_In_Texas I disagree a bit. I’d rather have two tanks: if one malfunctions I’ll still have hot water. Plus when not much hot water is needed I can only use one tank and isolate the unused one and keep only the pilot light on.

[@711stano]

It appears that a check valve is used on the left water heater hot out...why is this necessary?

[@joseartiaga3048]

How would it be ran if there’s 3 heaters do we need that same distance is kind of hard

[@richardgeisel4290]

You would be better to do them using reverse return/ last in last out. You won’t learn it from this guy. He would not understand it.

[@matrinstack4762]

I see that he says the piping must be of equal distance to each heater, one thing that is not taken into account is that on the heater on the left there are two extra elbows going into the tank. An elbow has a friction loss or is equivalent of a certain length of pipe. Example: if a 3/4 elbow where equivalent to 6 in of pipe, tank on the left has an extra one foot of piping. That's a guesstimate I don't know the exact engineering specs but it gives you an idea. So if you do the math the tank on the left has a longer piping distance.

[@diablo5983]

Thanks👍

[@jepomer]

These water tanks are connected in PARALLEL not in TANDEM. Tandem means "one followed by another". Your description is for tanks "side by side" referred to as parallel.

[@diablo5983]

Do you have to use copper or can you use PEX?

[@DERHOF2007]

Pex is garbage and for people that don't know how to do plumbing. Use copper... and even if you use pex you can't go all the way to the tank with it. You still need copper coming from the tank at least.

[@markfairbanks3533]

Pex is not garbage, and yes you can use it. If you live in cold areas like I do, where power outages last for days and the temperatures drop to below freezing regularly, PEX is the solution. Pex won't burst from a freeze. Also, to Andy, who can't plumb copper now? With insurance companies banning sweat connections, those compression/crimper copper fittings are easier to install than PEX. It's all about application. I personally think CPVC is garbage, but I use it a lot, because people have a budget.

[@gonz1479]

Do both water heaters have to be the same size?

[@Brisket9392]

Yes

[@stevedavis7519]

Why is it wrong to run in series?

[@richardgeisel4290]

Inefficiency

[@mickblock]

Because if one goes out you have to shut everything down to replace it. Barreled or tandom makes it so you can shut off only one supply and check valve the hot.

[@bobohara3974]

@@richardgeisel4290 Please explain

[@bobohara3974]

@@mickblock Not true, only if you neglect to put a infeed bypass in with the appropriate shut off valves

[@richardgeisel4290]

Should be manifolded or piped using reverse return

[@thomasmoye664]

No Vacuum breaker or expansion tank?

[@connerjake792]

Not on electric heaters, and check valve is optional

[@alwaysboatin659]

Your explanation makes sense, but your water heaters are not piped equally. There is a longer run on both the hot and cold in the water heater on the left.

[@Dave-ch4dr]

Yep! He f#cked up!

[@demmerdesign6356]

Lol I was ready to smash my phone while he is pointing at the pipes saying they are even. I mean, I'm sure there is not a world of difference with the extra elbows, but it has to amount to something. Ty for saying it bc it drove me nuts

[@Mello83420]

I literally turned to the comment section to see if anyone wanted to comment on this. You should be able to turn the WH to make it equal. No extra elbows.

[@donnimetropolis9899]

Yup that's why I came to comment

[@k2buildit]

Still waiting for an answer on this

[@bobohara3974]

Would love to hear why a Series setup shortens the life. Saying it doesn't make it so. Back it up with facts or don't say it.

[@nukedukem8424]

Well because that’s what Ray thinks, so he must be right. I’ve only ever done 2 heaters in a series and it works great. Saying something is wrong just because you think it is, is ridiculous. As you said “saying it doesn’t make it true”

[@jacquesrobin8086]

Because most of the time, only one water heater will work (the first one).

[@robertvandermolen230]

I would think that is good. One will do most of the work and then fail in about ten years and the other one will still have about five years of life left. Replace the bad one and still no worries.

[@62ejo]

Thxs good to know......

[@smartasasackofhammer]

I had to buy a little electric heater when my gas got cut off. I think I'll just turn it off when the gas is back.

[@altyndom7039]

But it is not the same distance since every 90 elbow adds around 5ft of length.

[@DERHOF2007]

It's not a flue pipe... I don't think a 90 in a water line equate to 5 feet of piping... do you have a source for this?

[@lastmin4603]

inlets and outlets are not piped equally. defeats purpose of the parallel system. left heater will be used more as the hot water outlet is closer.

[@DennisVeilleux-ll8im]

Good for the price but way to small for my home

[@promx96]

Replacing those is gonna be a pain in the ass without flex hoses

[@lookn2find]

Instead of relying on science, take a tandem setup with 2x tanks of the same size and see how many times you can fill up 2 bathtubs simultaneously before the water goes lukewarm or cold. Then test in series. My theory (just for speculation - I have no firm evidence): I feel like running in series is more efficient. Fill 1/2 water bottle with hot water. Fill 1/2 bottle of water and put it in the refrigerator until cold. Fill the rest of the bottle of hot water with the water from the bottle in the refrigerator. Let your 50/50 Hot/Cold bottle of water sit for a minute to simulate what goes on in a tank being fed cold water. Keep in mind it will be worse in a tank, because cold water is constantly flooding in for a much longer duration than it takes to simply transfer cold water from a bottle. Now imagine your tank with 70% cold water mixed with 30% hot. With a constant flow of cold, winter water, a tank being direct fed cold water is going to cool much quicker than it should. If you’re running in tandem you’re essentially putting the fire out, because immediately when you run hot water, very cold water is pouring in and reducing the temperature rapidly (during the winter - of course summertime makes use of a higher percentage of hot water before being neutralized). In tandem, with 2x 50 gal water heaters, let’s say the temp of both tanks are neutralized by the time you use 70% of your total hot water (because 70% of the water in each tank is now freezing cold). For example, we’ll say 70 gallons of water will be at peak temperatures from a tandem setup before your washing machine, dishwasher or shower(s) begin to run cold. In “Series”, 100% of the primary tank would be used before cold water begins to enter the primary tank. Then you would get another 70% at peak temperature before being neutralized, which means a possible 85 gallons (vs 70 in tandem) or 21% more peak hot water before it becomes neutralized. Theoretically, in series, a person would get 85 gallons of hot water vs 70 gallons in tandem (from 2x 50 gal tanks).That’s roughly 21% more water at peak temperature when being run in series. This is of course using the theory that 70% of incoming winter cold water neutralizes the water in each tank being fed cold water. Tandem cons: Roughly 21% less peak hot water. Roughly 21%+ more energy consumption. Longer wait time for 2 tanks to reach peak temps after 70 gallons have been neutralized by the cold water coming in. It would be a pain to try to shave after showering when all the water from both tanks (in tandem) are neutralized or cold. Peak temperature recovery time would be roughly 30 minutes to be able to shave, which isn’t good when in a hurry or trying to go straight to sleep after showering and shaving. In series (and again, in “theory”), if the theoretical 70 gallons had been used, there would either be 15 remaining gallons at peak temperature in this scenario, or the recovery time for the primary tank would be greatly reduced. It’s all theoretical, but something to consider. I plan to test this theory some day.

[@pjduck33]

Plus, with series tanks, when you don’t need peak volume, you can shut off the first tank and use it as a tempering tank instead. ¡Viola! No ice cold winter water hitting the main (second) tank. You would now have 50 gallons of room temp water going into the main tank before any would come in ice cold. So now you get the benefit of summer water all year.

[@shawnd567]

Why not series? Cut life in half? While parallel had its benefits, it also has several downfalls. This design seems like a waste of time and money compared to putting in an instant gas water heater. They might need that tank capacity once a week/month. 2 gas tank heaters are $500 a piece or $1000 together. Roughly 75-80% efficient. Instant water heaters can be had for roughly $1000 for a 90%+ efficient model.

[@brandonperschon449]

I haven't heard anyone explain why it's bad and how it will cut the life in half. They just say it's wrong.

[@demmerdesign6356]

@@brandonperschon449 idk why they phrase it this way since I've heard it from people before. But I believe the whole idea is that in series, you tank with incoming cold water will be the only one that ever fires and runs with any more minimal water usage. Since the 2nd tank in the series is in theory being fed water that is hot enough to keep its thermostat satisfied. There are theories about using them in series with the 1st heater (just picking numbers here) at say 130 degrees and then 2nd at 140-150 so they would both fire but then you definitely dont get double the capacity. Basically from what I understand about it. If they are both 50 gallons, until you have used a substantial portion of the last heaters capacity probably 30+ gallons, the second tanker in the series has never seen water "cold" enough to cause it to actually run. Meaning that hand washing and even some shorter showers may never trigger the second heaters burner to ever fire up. Though I dont understand why this would "cut the life in half" since if you had a single heater that heater would cycle just as much. Plus it's the stupid tanks that always fail for me. Never the burner or valve I hope I explained that well lol. I know the answer I've just never tried to type it out before.

[@joeshaughnessy3449]

Partial redundancy. If one fails you can valve off and run at 50% capacity. Replacing with a tankless is not always the best option depending on house layout.

[@kurtvonfricken6829]

@@demmerdesign6356 You are correct. Some people run them in series, some in parallel. I’ve seen a set up where you could do either depending on which valves were open and closed.

[@AUXdrone]

Just replaced my two heaters that were in series and left them plumbed that way. They were 17 years old with nearly consecutive serial numbers. The hot-fed heater does fire but obviously not as much. Going to run the cold-fed heater a bit cooler than the other to even out the fire cycles but we essentially have endless hot water for all our needs. Only when we have family over (up to 10 people in the house) do we notice any difference. The recovery gph on my new heaters is a standard 84 gallons each at +90°. So wouldnt that make the series setup essentially 168 gallons at 130° water if we could somehow demand that much hot water? I am just a diy guy not a professional, would love some professional input as to why my heaters would last half as long and to correct any error in my math?

[@rocknessrocker]

I disagree. Not with all of it but your reasons for not hooking them up in series is just insulting and condescending at best. Not trolling or instigating so I apologize if this sounds rude. Hydronic Science reasons? How does it cut the life of the water heater in half? I also dont think "hydronic" is the term that should be used here. Hydronic means the distribution of heat by using circulating water. This is almost hydronic but it isnt circulating the same water and it isn't distributing "heat." It distributes hot water, not just heat with or by hot water as it circulates. Circulating.water is warm coming in and hotter going out than in the loop there is heat sinks that warm the room or anything that needs heat. See what I mean? The fact that he used a techy sciencey term incorrectly means he was just using the word to sound like he knew what he was talking about when in fact he did not. He probably had been taught that way without a proper explanation thus dooming him to do the same thing. The life of the water heater wouldn't be cut in half from being hooked up in series......sorry but i need more info especially if you are tryin to use tech jargin to get past having to learn why you do something. What if there is a propane burner inside a natural gas water heater and you hook up an electric water heater in series? You won't need the gas water heater all the time but the gas heater will store and insulate more hot water than just the electric water heater by itself AND the gas by itself. Not everyone is a soccer mom uninterested in how things work.. I also think the use of the "Hydronic sciency reasons," was condescending and disappointing to hear from a content creator the I enjoy watching so much. Sorry man but i think he got lazy on this video. I definitely feel like a jackass now.......

[@charvakkarpe]

Nice. I was going to call him out for "hydronic science reasons" but you already did!

[@charvakkarpe]

Also, who's the jackass when he blatantly ignores those 90 degree elbows. He obviously installed the upper equal length pipe before realizing the left side needed to be longer, then instead of just extending the end of it he added two unnecessary bends.

[@ricklee827]

Water is going to follow the least path of resistance and how that is pipe is extremely wrong do not listen to this video

[@AlexGarcia-ur9dy]

I gave you a thumbs down. The hot and cold water pipes are clearly not symmetrical.

[@WApnj]

This is not a tandem installation .. It is in parallel...

[@richardgeisel4290]

Not right, should call a professional

[@saltypipefitter4618]

Absolutely abysmal pipe fitting

[@donnimetropolis9899]

Explain please

[@philflores4939]

I Totally Disagree . This is not a correct install .

[@davidt1487]

Your wrong they other way works just fine

[@adamhe8778]

You need each switch for each boiler just for in case one failed over