Rheem Tankless Water Heater Installation - User Corrections

[@retiredperson4054]

Thanks -- I was going to tell you about that on the first video! But I was going to be NICE LOL A man who can admit his mistakes is a MAN I can work with! (FYI -- I worked all types of construction for over 55 years)

[@macdaddymac6785]

A man who puts himself out there to be perhaps criticized and at least corrected......openly admits his mistake, AND......AND corrects the mistake! And then thanks the people who set him straight. Kudos to you Scotty! I wish the world were more like you sir. I'd love to buy you and drink a beer with you. It shows real character. Thank you. Taking this project on myself and I nearly "logic'd" myself into the same mistake you made with the negative slope. Strong work. My old boss when I was a young carpenter's apprentice used to say, "It ain't broke if you can fix it. So get to it!"

[@FixItScotty]

Thanks for the kind words! In my real life, I get paid as a software engineer, not as a plumber, auto restorer, carpenter, or electrician. Some think it is a weakness to perform work on a KZbin channel that's outside of their profession; I think it's a strength because it's easier to understand the struggles and explanations coming from a fellow layman. Hope your install goes great!

[@doublezmtnman]

Water is not going to come in from the outside. The heat chamber in the heater is so efficient that it removes most of the heat from the exhaust and because of this the exhaust will condense water inside the pipe as it cools even more on its way outside so this water condensing inside the pipe has to drain back to the heater to the condensate drain. If it becomes trapped in the line it will cause a restriction in the amount of flue gas the heater can discharge causing back pressure which can cause your heater to fault out. And you don’t put screen over the exhaust because in extreme freezing temperatures the moisture in the flue gas can freeze on the screen and restrict the discharge causing the same problem as water trapped in the pipe. These high efficiency heaters have pressure switches that detect proper flow through the exhaust and intake pipes. Just remember only the person who never does anything for themselves will never make a mistake. Keep up the good work!

[@FixItScotty]

Thanks for the great information!

[@doublezmtnman]

@@FixItScotty Its awesome when we can use our experiences to help one another. I like how you repost to show corrections that takes a lot of integrity on your part👏👍!

[@hellobrandonscott]

Is that flexing on the front cover (at 14:53, for example) normal? Mine does that too but I started thinking perhaps it was from inadequate ventilation, but here's an example of it doing that with proper venting.

[@FixItScotty]

I'm not experienced with other units, but my has always made that front-cover clunk when it starts up. At this point, it is 4 years old and has worked flawlessly. So I assume it is normal.

[@hellobrandonscott]

@@FixItScotty OK good to know! Thanks a bunch!

[@z01sne]

great series...the only thing you failed to touch on was that the condensate generated by the heater is acidic due to the process. Dumping acidic condensate into metal drain lines is never a good idea. Your house appears "older" and I would imagine it has lead or iron piping. You should really install a condensate neutralizer to the drain hose.

[@FixItScotty]

Thanks!! The only reason I haven't had issues with the condensate is because that basin sink (where my water softener discharges) is not level and always has a little standing water in tub. So by the time the condensate gets to the main stack, it's pretty well diluted. But, you're right, I should add a condensate neutralizer to prevent problems.

[@PigsOnBook]

I keep coming back to these videos, thanks again. Did you have any hold up buying sch40 pvc pipe and elbows, in regards to elbows say on them ASTM D-2665 and straight pipe says D2665 AND ASTM D-1785? My Rheem manual says, page 22, acceptable exhaust is D-1785, then has a separate row in same table, D-2665 is approved for fittings. But I cannot find an elbow fitting that has D-1785 etched on it from Lowes or local plumbing supply. Rheem wasn't exactly sure, but we discovered that straight pipe seems to be in both ASTM families, because it has in red writing, D-1785 and 2665, and maybe elbows are in the D-2665 group only, as fittings. If elbows only say only D-2665, is that good?

[@FixItScotty]

Thanks for watching! Both ASTM D2665 and D1785 are SOLID CORE sch40 PVC which is very important for this application. I believe D1785 can handle higher pressure (and maybe heat) than D2665. That said, all my piping is rated ASTM D2665. I never got any specific guidance from Rheem that I needed D1785 pipe or fittings; the exhaust doesn't seem hot enough or high pressure enough to warrant it. But keep in mind, I am a DIYer and neither a licensed plumber or professional support tech. So don't consider me an authority on the subject. Call Rheem support and see what they say. Good luck on your implementation.

[@PigsOnBook]

​@@FixItScotty Awesome. Thanks! It appears 2665 is the rating for Drain, waste, VENT applications. and Charlotte brand helped me figure out a 2665 elbow can be used to connect to a 1785 pipe, and will say 2665 on it, even if 1785 is not printed on the elbow. Another lesson learned.

[@robertc5772]

Thanks Scott. You taught me something about that particular install. You all right with me

[@ehrensmith915]

This series was most helpful. You are graceful in your replies to comments from people who are not brave enough to make their own videos and face criticism. Nice work Sir!

[@FixItScotty]

Thanks so much for your encouragement! As this video shows, I am lucky to have several smart and respectful commenters on my channel who I value their insight. The occasional hateful, immature commenters are just part of the inevitable youtube landscape.

[@twbrkfd1733]

I commented on that exhaust install in your other video. It didn't make sense then because you would be blowing acidic air into the paint on the wall. Good to see you discovered the problem. With the pitch, it is so condensate will drain back to the condensate pump and not collect in the pipe or drip out on the ground.

[@FixItScotty]

Yes, thankfully multiple people like you respectfully called it out to me and I addressed it. Thanks for watching and giving advice!

[@chrisgoodell6666]

Hey Scotty, do you happen to remember the Oncenter spacing that the that the termination is that for? I'm roughing 1in tomorrow and I don't have the plate yet. Thanks

[@FixItScotty]

I was out of town, so apologies if this reply is late. The on-center spacing is 6".

[@ryanshackelford6721]

I just installed a Rheem Prestige Combi Boiler. I was wondering if they are normally already factory set in the settings to fire it up because im kinda leary or should I maybe hire a professional to give it a once over first.

[@FixItScotty]

Yes, I would recommend hiring a pro to give it a once over. I have worked on boilers but don't have any experience installing or maintaining high-efficiency combi boilers. So my advice is limited, As you know with boilers, you do have more settings and limits that need to be reviewed. Also, unlike water heaters, you need to purge the heating lines of air. These additional tasks take a bit of knowledge to get right.

[@ryanshackelford6721]

@@FixItScotty thanks for your fast reply for info greatly appreciated.

[@runwayray]

A good tool for cutting PVC is a ratcheting PVC cutter. Makes a very clean cut easily, no movement of the pipe I have a Rheem HE condensing WH for 5 yrs. Works great. Natural gas supply is very important to run these units. Hard pipe to them, don't use corrugated gas supply line. You want as much gas as possible. 3/4 to one inch pipe will satisfy demand for the unit. Some Gas companies have more efficient meters for HE appliances. Main thing is that you don't want to fuel stave your tankless heater, it may cause damage.

[@FixItScotty]

If you have a recommendation for one, let me know. Either my hands aren't strong enough or the one I have is cheap, but I can only use it on thinner, smaller pipe.

[@runwayray]

@@FixItScotty I admit that they need some force to use. I use two hands when cutting two inch pvc but able to do it with one when I need to. I have a husky ratchet cutter but more and more companies are manufacturing cutters. Milwaukee has one that looks pretty effective. I saw couple of other that I yet to find out who makes them, looked really easy to cut pipe with. It had a larger gear box. They are out there in growing numbers. Regarding having same length of intake and exhaust pipe, the pressure switch will not function properly if the pressures are extremely different. For the unit to start, it must detect that the induction fan is operating and that neg pressure created ensures flames travels in the correct direction of the fire box and out of the flue. If the pipes length extremely different, the delicate pressure switch just won’t function and stops the safety sequence. Very similar to force air furnace. By the way, you have excellent workmanship and narration

[@FixItScotty]

@@runwayray Thanks so much for that information. That is greatly helpful!

[@jaxsonhugh9334]

The reason the exhaust vent has to be tilted back towards the unit is for the condensation that is part of the exhaust to drain back into the condensate drain

[@FixItScotty]

Correct.

[@alberthoogendoorn2396]

I am very impressed with your videos “How to install a tankless water heater”. Very informative etc. I will start tomorrow with my Rheem project and look forward to it Thank you.

[@FixItScotty]

Thank you! Good luck on the project.

[@mtboverholts253]

Hello Scotty! So we were wondering about a situation where the water heater and furnace are in the same location. Our's are in a ground level closet in the garage and my brain says that I can use the existing exhaust vents for the furnace to vent the exhaust for the "new" tankless water heater since the 50 gallon hot water tank already uses that same vent....we are installing a 200,00 BTU 11 GPM tankless from Rheem and all other variables are the same. There is also a 4" intake vent already open to the outside air that I would pipe the intake into. So we really want to know what you have to offer for this situation.

[@FixItScotty]

It's hard for me to give advice on venting because I am not qualified and I can't see it. That said, remember that a typical tank heater uses metal exhaust because the output is hot dry gas. The tankless (and high-efficiency furnaces) use PVC pipe because the exhaust is wet and corrosive to metal. Talk to Rheem support about the venting for advice. Also, very important... make sure you evaluate your gas meter and line sizing before moving up to the tankless. Your current heater is probably under 40K BTU. Now you're moving to 200K BTU - that's quite a jump in needed pressure. For me, I could just barely fit in the increase gas demand on my current meter. But for others, they may need to upgrade the meter and possibly some of their gas piping.

[@fastsvo]

How does one keep the condensation from dripping between the PVC couplers and elbows in the run? Silicone sealant?

[@FixItScotty]

The condensate should never seep out of your PVC joints as long as they are glued like any normal PVC drain pipe.

[@huannguyen3820]

Hi, how is your tankless water heating doing? Is there any issue with it? I am looking for to install one at my house.

[@FixItScotty]

It is only 2 years old, but so far, no issues.

[@twbrkfd1733]

BTW the exhaust acidity is about that of orange juice, but over time it will accumulate if just dumped on the ground in one spot.

[@lucylee1658]

How long does it take to get hot water?

[@FixItScotty]

Good question. How long it takes depends on where you are in the house, but on average the tankless takes about 10 seconds longer than a tank water heater to get hot water.

[@twbrkfd1733]

What will also affect how quick the hot comes is the size of the water pipe. 3/4 has TWICE the volume of water it has to push through!

[@vica153]

DWV PVC!!!!!!!!!!!!!! If you're not dead from CO poisoning, then you should fix that and update these videos.

[@FixItScotty]

"DWV" (drain waste vent) does not indicate whether it is cellular core or solid core. It is the ASTM number. This is standard ASTM D2665 solid core PVC. If you want to argue I should use ASTM D1785 for higher pressure applications, that is valid. But I have no CO levels in my basement.

[@munieco70]

where is the water created by the moisture in the exhaust pipe supposed to go? help, please

[@FixItScotty]

William, when the moist exhaust gas travels upward inside the pipe and out toward the outside of the house, some of it will cool into water and fall back toward the water heater in the pipe. That water that runs back into the water heater and escapes out of the condensate drain (the plastic tube). I describe this at 19:10. Thanks for watching!

[@twbrkfd1733]

Of course water got trapped. It is the condensate! The small amount of pitch will have NO bearing on the blowers ability to push the gas out. The purpose of the pitch up is to cause the acidic condensate in the pipe to drain back to the condensate drain at the bottom of the heater/pump. In addition, this is a BIG issue because a typical install would only have an elbow pointing up for exhaust an done down for intake and NOT be using that Mickey Mouse flange kit. With the elbow, condensate would pool in the pipe and eventually fill it. Oops! FYI I have the same heater! Nice job on hacking those joists!

[@tfern6750]

Thank you for your video series on tankless water heaters. it was very informative and covered a lot of information. Also, it wasn't rushed and covered the installation in a way that most can understand. i look forward to seeing new content from you. Will be doing this soon, once saw the intake and exhaust, i realized that having the water heater in the attic of a 2 story house will require me to rent a ladder when i cross that path. Thanks again

[@maj.horace3709]

boy-oh-boy - thoughts and discoveries aplenty. First - my Rheem died 4-years after install (error 61 - fan failure). The pipes were parallel to the ground - NO PITCH towards the Rheem unit on the Exhaust (pg 31) and parallel Intake pipe. Water built up in exhaust line and I pulled fifteen-gallons plus of water out. Rheem update indicates (as of 07 March 2020) exhaust pitch away from Rheem unit (can provide instruction). Also, a condensation trap - inline with the intake as close to the Rheem unit as possible - is mandatory; it was explained that the temperature difference between the air intake and the Rheem unit burner will cause condensation and the Rheem unit can NOT handle water intake for the burner. With the problems and changes of the install (contractor) I am ready to pull the unit and install a tank.

[@ATappin]

So pitch it away from the unit or towards the unit for the exhaust?

[@FixItScotty]

Pitch it towards the unit. The water should roll back into the exhaust which will roll down to the condensation output.

[@tonytone3424]

Do you need to install a sub pump like the gas furnace has?

[@z01sne]

The reason the condensate should drain back is so the secondary heat exchanger can capture the remaining heat in the condensate, thus making the heater so efficient and the exhaust is cooler which allows for PVC piping

[@twbrkfd1733]

Why not just chip out some of that non-load bearing limestone and shorten the pipe at the heater 2 inches? Then you will have the proper slope on the entire run.

[@thankswillie]

nice job bro,nothing worst than a pro,that does a shit job....you did good

[@twbrkfd1733]

NO PITCH is needed on the intake! Wasted effort...

[@FixItScotty]

Makes sense.

[@hellobrandonscott]

The instructions state that even the intake pipe needs pitch.