Low HW pressure on Tankless System

[gmrules]

I have Nortiz Tank less HW system in my house till recently I had good HW pressure, Now when I turn on more than 1 facet have little to no pressure.

I am on a private well who water is little hard and I do get calcium build up on the show heads and the tiles and the toilets do show the brown / orange stains

Today I cleaned out the strainer on the cold water inlet to the unit hoping that would be my problem but it was not.

I am suspecting the heat exchanger needs to be flused and cleaned out with like CDR or something like that to de-scale it.

Am I on the right lines or completely off base?

any ideas or feedback would be greatly appreciated

Thanks
george

[MACPLUMB 777]

:D

YES MERRY CHRISTMAS;

DO NOT USE CRL;


you need something safe for drinking water, ie; potable water,
use eather white vinger or AO SMITH sales a food grade acid to flush though
the heat exchanger this may several passes to clear out the lime buildup:(

then flush with clear water a couple times before putting back into service:D

JERRYMAC MASTERPLUMBER PH.D WATER HEATEROLGY

[GrumpyPlumber]

Two other items, check the cold inlet for a screen...you might just have sediment clogging it.
If the GPM rating is 3 GPM or less, it's the flow restrictor...which means your unit is undersized.
You should do a vinegar flush at least once a year, depending on your water content.

[gmt]

I concur with the two posts above.

Additionally, it may be undersized and is compensating for keeping the water temperature at the desired setting. Some of the units will restrict the flow in order for it to get the water warmed up to the required temperature.

[srdenny]

From my experience with Noritz, I'd say it's the screen on the cold inlet.

[master plumber mark]

I am not starting trouble here...

but I would be interested in hearing how hard the water is??

wether they have a water conditioner or not.??


and how long has this tankless heater has been installed??


If the filter is jsut the only problem you will be lucky

If it needs to be de-limed , then it is something you
will have to do "every so often"


that is what I am curious about...

[construct30]

Master plumber mark is possibly correct. Fix the problem not just the symptom.

[srdenny]

Deliming with CLR is not too difficult if you have these installed on your heater.

[master plumber mark]

those isolator valves are aobut 100 bucks and should
be installed at the time of the original install....


what do you charge to de-lime a tankless heater????

[srdenny]

I haven't had to do it, yet. But I've got a Zoeller dewatering pump, hoses, bucket, and a bottle of CLR ready to go when the first call comes. I figure it should take about an hour w/a little travel time added in ($150.00). As for the $100.00 cost for the iso valves, they come with a pressure relief port and a pressure relief valve. Add that to the valve you would have had to put on anyway and the true cost comes down to about $60.00. Plus, they install quickly. I usually put in the bigger units, so an $100.00 really isn't an issue, especially when you consider the cost of the Cat III flue pipe.

[gmrules]

Thanks all that replied, to answer some of your questions

Its a Nortiz N-084m (LP)
Its in 3 1/2 Years
Water Kinda Hard Just happen to have the
water tested by the county

Calcium 30.0
Chloride IC: 40
Cooper <.05
Iron : <.10
Hardness :as CaCO3 (Ca,MG) 101
Magnesium 6.4
Manganese : <.03
Lead <.005
PH 7.4
Zinc .97

I do get build up at the shower head of the white crap

I do not have the isolating values installed, I was wondering if I could do this

The heater is sweated in BUT, it converts back to PEX in my crawl which I can stand up in, so I wanted to install isolating values on the PEX Like so:


Heater ------- Tee -- Ball Value -- House
|
|
Ball Valve

Do this on both Hot & Cold, Would that not Isolate the Tank so I can de-scale it?

Where could I get Food grade vinegar? How long do I run the pump to clean and then to flush?

I am sure this is the issue. I did clean the screen was not too dirty BTW,

Thanks so so much Happy New Year

George

[GrumpyPlumber]

Valve on cold only.
Put a draw off between the cold valve and the inlet, then a draw off on the hot side, no valve.

[Bob NH]

You get food-grade vinegar at the grocery store. You can probably get gallon size at some of the warehouse outlets.

It works better if the vinegar is hot. Put a couple of gallons in a bucket and pump from the bucket. Dump the return in the bucket and keep it hot.

I don't know a good way to measure when it's done. It only takes about 5 minutes to clean a really bad teakettle but that is with the vinegar boiling. I suspect that it will take longer with a water heater.

You can probably save the vinegar for a second time.

[Cass]

Based on the cost of vinegar I would toss it.

Phosphoric acid or citric acid will work also, flush well with water when your done, 3-4 times, B 4 placing it back in service.

[gmrules]

If I do not put a valve on the hot side how can I isolate it and recover / recirculate?

George

[master plumber mark]

How exactly do you know when you have
flushed out these things anyway????

When do you know you are back to max efficiencey again???

I mean, do you get a murkey , frothey kind
of chicken soup thing going in the vinegar after
about a half an hour

or are you supposed to let the vinegar sit still in
the exchanger for a 15 minute period then flush it out
and repeat the process over and over agian till the

vinegar looks nasty????

[GrumpyPlumber]

If I do not put a valve on the hot side how can I isolate it and recover / recirculate?

George

A pump into the cold with a return off the hot side...as long as all hot fixtures are closed you're fine, though it will go into the hot line a bit...the flush has nowhere else to go.

Also, another effective cleaner, DON'T laugh...unsweetened concentrated cool aid.
It has citric acid, as Cass states above.

[gmrules]

Thanks all for you r advise

I will be doing it this weekend

[master plumber mark]

No one cared to answer my queston...

perhaps it was s stupid one, perhaps not.....


How long a process is this and how or when do
you know that you are back to 98% eff again??

[gmrules]

Sorry Mark

According to Nortiz 45 mins you need to circulate the solution

I was expecting a more experienced person to answer :)

[gmrules]

Well, I finished the de-scaling with very limited success, I did not get chance to head over to SAMs to get larger vinegar so I used CLR as recommended by Nortiz

I ran it 50 mins and only helped little bit. Was so disappointed

I will head over to SAMs and get the vinegar and heat it as BOBH suggested

its a little better no where near normal

[Bob NH]

CLR is a fairly dilute solution of 15 to 20% lactic acid and 2 to 4% gluconic acid. See the MSDS at the link below.

http://www.hescoinc.com/Msds/comcl4.pdf

They are both pretty mild acids and one of the most significant aspects of CLR is that it is unlikely to hurt you.

Gluconic acid: http://www.jungbunzlauer.com/products-applications/products/gluconates/gluconic-acid/general-information.html

Lactic Acid: http://www.encyclopedia.com/doc/1E1-lacticac.html

CLR is expensive for the amount of acid that you get. I would use hot vinegar because I know it will work. If I knew that the heat exchanger was stainless steel I might use about a 5% solution of muriatic acid (hydrochloric acid).

http://www.improvingyourworld.com/home/how_to_get_rid_of_hard_water_build_up_000482.html

[GrumpyPlumber]

No one cared to answer my queston...

perhaps it was s stupid one, perhaps not.....


How long a process is this and how or when do
you know that you are back to 98% eff again??


. But I've got a Zoeller dewatering pump, hoses, bucket, and a bottle of CLR ready to go when the first call comes. I figure it should take about an hour w/a little travel time added in

I'd have to say 1/2 to an hour, depending on water content & length of time from last flush.

[master plumber mark]

Sorry Mark

According to Nortiz 45 mins you need to circulate the solution

I was expecting a more experienced person to answer :)


You really cut me deep.....dude......deeeeeeeeep.....



But this is not my frist trip to the Rodeo, .............

http://www.weilhammerplumbing.com/houseofhorrors/

I have thrown out tankless units that were totally
limed up over the years,
because they were never de-limed ......

its only been a long time since the last one I tangled with....



anyway, now you know what a long painstakeing affair it can be to

actually service one by finding out for yourself...




SRDENNY......
I wonder what you would have charged to get yourself
into a day long event like this??

what is the min. you woulld touch it for??





perhaps you ought to let the CLR sit in the system
overnight and see if it works its majic...

if that dont work then you got big troubles...





So Grumpy, if the unit has been de-limed every 6 months,
a half hour is a goood rule to go by..................

if it has been longer, you could get yourself into troubles...

[gmrules]

heating the vinegar as I write this

should have listened to u in the first place :)

my bad

ty for taking time to help me

[gmrules]

Just finished not much better :confused::(

do not understand

any other ideas?

[Bob NH]

Do you have or can you install a pressure gauge on the inlet and outlet sides of the water heater so you can know how much loss there is, and compare it with the rating from the manufacturer? You would need to know the pressure difference and the GPM for that condition.

Have you checked to verify that there are no screens or valves anywhere in the system? Some of those heaters have a control that limits the flow if the water is not up to temperature.

[gmrules]

I have on pressure gauge

i can measure it as I put in bolier drain to flush

[gmrules]

I can get static pressure

[GrumpyPlumber]

Aaaaannndd??

[master plumber mark]

as a last ditch effort.....

just let the CLR sit overnight in the unit....


just out of curousity , have you tried to simply blow

air through that exchanger and see what happens???


what kind of resistance you get......

static pressure dont mean a thing,

it will lbuild up pressure on the guage


its the flow, flow , flow ...so you got to blow,

through the exchanger you want to get a handle on

whats going on inside that exchanger.......


just put your mouth on the end of the
pretty brass pipe and blow....

[GrumpyPlumber]

I've said this before, Mark...you ain't right.

[master plumber mark]

Honestly Grumpy,

didnt you ever "siphon gas " out of a car before
when you were a teenager??

wouldent just blowing air through the
damn thing tell you all you need to know
about obstructioins in that exchanger???
------------------------------------------------------

If useing your mouth makes you nervous,

and it reminds you of being pulled over by the cops and
having to take a breathelyzer test....

or whatever else you can think of ................

then just go get an air compressor .....


because that air resistance
is gonna tell you wether you have freed up
system or not..

If the job is done right,
the air should just pass through it freely,
like when it is new.

wouldent you think??.

-----------------------------------------------------------


also on another note, -- to cover your ass,---
when you sell these things
to the public, do you ever mention something about
de-limeing them every 6 months or so ???

Have you ever thought of selling a bi-yearly
maintiance agreement to the customer for $195 ?


if for no other reason than make them aware of this
situation??

[Redwood]

Have you been through the winter with this unit before? If so how was its performance then? Could it be Undersized? Where are you located?

[GrumpyPlumber]

Actually it occured to me afterwards that Mark, and Redwood right above, have a good point.
You might try running it while it's off and see if the same flow dilemma occurs.
If not, then you either have a defective/clogged flow restrictor or flow sensor.

[master plumber mark]

I wonder Grumpy if these parts should be taken out
of the unit BEFORE you run CLR through it???


what does the manuel say...???

[GrumpyPlumber]

I wonder Grumpy if these parts should be taken out
of the unit BEFORE you run CLR through it???


what does the manuel say...???

You or I could do a websearch and review the manual, but I doubt it.
The fact that they say use CLR surprized me though.

[master plumber mark]

I suppose that would be

"criticle..... need to know..... information"

something you should be keenley sure of
before you go screwing up someones 1200 dollar
tankless unit.......


We have not heard back from this fellow ---so

in my humble opinion.......

delimeing these things appears to be a pistol to
tackle

and it would seem wise to take out any
internal parts that might get com-pro-mised
(screwed up) by the vinegar or more
toxic substances you throw through it

maybe it is not necessary to do...but if it is
that could be another difficult project in itself


I doubt that CLR is too wise unless the people
at the tech suport say its ok....

muratic acid is certianly out of the question
when you dont know how tough the flow sensor
or other parts are .....




I have a Nortiz 6.9 unit in my shop new in the box
I will look at the specs tomorrow....

all I know about the Nortiz uint is that if you
do not de-lime the unit quarterly it voids the
lifetime warranty on the heat exchanger....

[master plumber mark]

I am very curiouis as to how this thing
has all played out.....


their has been no responce for days and I am beginning
to wonder

did this fellow win, lose or,,, draw...



with the ones I ever stumbled upon.....
usually the wife was already so
irate about the cold showers that they were ready to
tear the thing out and install a 50 gal gas unit...



I am getting the feeling that he is mad at me...





inquireing minds want to know...

[master plumber mark]

Still waiting on a reply......

did you get that puppy working right??

or have you thrown in the towell??

please give everyone an update on what has transpired....

[gmrules]

So Sorry for the delay in the update, I had both my knees replaced been layed up

Was semi successful in the de-limeing, works better but not 100%

Will get back to it when I am recovered

thanks for all your help everyone

George

[GrumpyPlumber]

Thought this thread a good place to post this...
Got a call from a customer I installed a tankless for over 1-1/2 years ago...LOL.
"I...um...think you'd mentioned we're supposed to flush this thing once a year, I forgot how you said to do it...any chance you could do it?"

I go over and show him how to set up the pump, flushed it with 3 gallons of vinegar ($2 a gallon at Costco).
I let it run for a full hour and..HOLY MOLY...it was BLACK!

For those of you who own them, it's VERY simple to do, no parts to be removed - they get cleaned as well, plug & leave, come back an hour later and thats it.
Nothing complicated, no serious issues, just a small pump with two double ended washing machine hoses connect the the cold inlet draw-off, close the cold valve and let it circulate the vinegar through the hot draw-off through a 5 gallon bucket while you get on with life for an hour or so.

[gmrules]

WELL here I am in the same BOAT very LOW pressure through my unit

I have date with my vinegar tonight

[gregsauls]

Thought this thread a good place to post this...
Got a call from a customer I installed a tankless for over 1-1/2 years ago...LOL.
"I...um...think you'd mentioned we're supposed to flush this thing once a year, I forgot how you said to do it...any chance you could do it?"

I go over and show him how to set up the pump, flushed it with 3 gallons of vinegar ($2 a gallon at Costco).
I let it run for a full hour and..HOLY MOLY...it was BLACK!

For those of you who own them, it's VERY simple to do, no parts to be removed - they get cleaned as well, plug & leave, come back an hour later and thats it.
Nothing complicated, no serious issues, just a small pump with two double ended washing machine hoses connect the the cold inlet draw-off, close the cold valve and let it circulate the vinegar through the hot draw-off through a 5 gallon bucket while you get on with life for an hour or so.

I bought a little pump from Harbor Freight that powers off a drill. Works great for less than $10!

[Ladiesman271]

I bought a little pump from Harbor Freight that powers off a drill. Works great for less than $10!


That earlier Grumpy Plumber post goes back to 2008.

Pool cover pump (http://secureshopping.mcafee.com/little-giant-pump-company-518025-swimming-pool-cover-pump?pid=209801164&cid=489)

[Ladiesman271]

WELL here I am in the same BOAT very LOW pressure through my unit

I have date with my vinegar tonight



Check the water heater inlet filter once a year. If that is clogged up, that creates a flow problem. Flush / descale should be also be performed once a year.

[jadnashua]

Check the water heater inlet filter once a year. If that is clogged up, that creates a flow problem. Flush / descale should be also be performed once a year.
The inlet filter condition has little relation to how much, if any, mineral deposits are in the heat exchanger. The filter is catching sand, and other crud that may be in the inlet water, not minerals, unless they are already precipitated out of the water. Think tea kettle...it WILL get mineral deposits in it unless you use softened water through it.

[Ladiesman271]

The inlet filter condition has little relation to how much, if any, mineral deposits are in the heat exchanger. The filter is catching sand, and other crud that may be in the inlet water, not minerals, unless they are already precipitated out of the water. Think tea kettle...it WILL get mineral deposits in it unless you use softened water through it.


While that is true, my response was to these words:

"WELL here I am in the same BOAT very LOW pressure through my unit".

Check first things first is my procedure. Note that I also recommended an annual descale. Just because you descale does not mean that the filter is clean. A somewhat clogged tankless water filter will reduce water flow everything else being equal. With a somewhat clogged inlet filter, it is also difficult to descale in a reasonable amount of time anyhow (AKA low flow).

[SewerRatz]

The joys of a tankless unit. Be right back I need to check the inlet filter on my tanked unit... oh wait there isn't one.

This is the other issue about tankless units they do need to be maintained and will show signs of neglect faster than a tank unit. This is why I explain to whom ever calls me to install one of these that they must commit to maintaining it on a regaler basis.

Now that I got my little rant out of my system. Yes I would check the inlet filter if your unit is so equipped. Once you verify it is clean, then proceed to delime it. Instead of vinegar A.O. Smith makes a product called Un-Lime that works great, the even have a pump kit for coil type heaters which is another type of heat exchanger. Part number for this pump is Parts No. 4930 and the part numbers for the solution is PART NO. 4763-P4 (1 Gal. Size, case of 4)
PART NO. 4813 (5 Gal. Size)

[Ladiesman271]

The joys of a tankless unit. Be right back I need to check the inlet filter on my tanked unit... oh wait there isn't one.

This is the other issue about tankless units they do need to be maintained and will show signs of neglect faster than a tank unit. This is why I explain to whom ever calls me to install one of these that they must commit to maintaining it on a regaler basis.

Now that I got my little rant out of my system. Yes I would check the inlet filter if your unit is so equipped. Once you verify it is clean, then proceed to delime it. Instead of vinegar A.O. Smith makes a product called Un-Lime that works great, the even have a pump kit for coil type heaters which is another type of heat exchanger. Part number for this pump is Parts No. 4930 and the part numbers for the solution is PART NO. 4763-P4 (1 Gal. Size, case of 4)
PART NO. 4813 (5 Gal. Size)



I guess that you forgot about the maintenace schedule on tank type water heaters. Did you ever take the A.O. Smith tank water heater maintenance training course?


Is regular monthly draining of a tank type water heater required? Yes!

Is deliming required in a tank type water heater? Yes!

Is anode rod inspection / replacement required in tank type water heater? Yes!

Is your warranty void if you do not descale a tank type water heater on a regular basis? Yes!



A.O. Smith Tank Water Heater Maintenance Requirements (http://www.hotwater.com/lit/training/4800r9.pdf)


PRESENTED AS A SERVICE TO THE PLUMBING TRADE BY

A.O. Smith Water Products Company


For many years the importance of establishing an effective preventive maintenance recommendation for tank type water
heating equipment has been recognized. Due to a combination of factors, including limited tank access and lack of
suitable scale removal products, such a program had not been developed. In addition, the low input, small tank size
heaters of the past operated in a generally satisfactory manner for long periods of time with little or no attention.

With the advent of higher input, larger tank size heaters in both commercial and residential models, maintenance has
become a problem that must be faced and dealt with to obtain maximum unit life and user satisfaction.


When

Aside from monthly tank flushing performed by opening the
drain valve (with the water inlet valve left open to maintain
pressure in tank), and allowing the water to flow until it runs
clean; maintenance should be as indicated until experience
indicates the interval for a given operation should be
changed ...to a shorter or longer interval.

Changes in water hardness, hot water usage and outlet
water temperature may affect the lime buildup in the heater
or on the elements. Therefore changes in any of these
factors may require deliming to be done on a different
schedule.


Gas and Oil-fired Units

The depth of lime buildup should be measured periodically.
Heaters equipped with cleanouts will have about 2" of lime
buildup when the level of lime has reached the bottom of
the cleanout opening. Heaters without cleanouts will have
about 1" of lime buildup if it has reached the drain valve
opening. A schedule for deliming should then be set up,
based on the amount of time it would take for a 1" buildup of
lime. It is recommended that the water heater initially be
inspected after 6 months.


Example 1:

If initial inspection after 6 months shows 1/2" of lime
accumulation. Therefore, the heater should be delimed once
a year.


Example 2:

If initial inspection after 6 months shows 2" of lime accumulation.
Therefore, the heater should be delimed every 3 months.


Electric Units

A hissing sound may be heard as lime scale builds up on
the residential water heater elements. When this is noticed,
the elements should be removed and delimed.

Commercial water heater elements should be delimed as
determined by periodic inspections. If elements are limed,
a shorter interval between inspections should be scheduled.



Anode Rod Inspection

The anode rod is used to protect the tank from corrosion.
Most hot water tanks are equipped with an anode rod. The
submerged rod sacrifices itself to protect the tank. Instead
of corroding the tank, water ions attack and eat away the
anode rod. This does not affect the water’s taste or color.
The rod must be maintained to keep the tank in operating
condition.

Anode deterioration depends on water conductivity, not
necessarily water condition. A corroded or pitted anode rod
indicates high water conductivity and should be checked
and/or replaced more often than an anode rod that appears
to be intact. Replacement of a depleted anode rod can
extend the life of your water heater. Inspection should be
conducted by a qualified technician, and at a minimum
should be checked annually after the warranty period.

NOTE: Anode rod inspection may need to be made
more frequently in areas subject to acid rain that obtains
their water supply from surface water as the low pH
will accelerate anode activity.


.

[SewerRatz]

I guess that you forgot about the maintenance schedule on tank type water heaters. Did you ever take the A.O. Smith tank water heater maintenance training course?

.

Did you take the course? Also did you take any of the tankless water heater courses. I have and I have the certificates to prove it. My point of my little rant is most people do not do the maintenance required on a tanked heater mainly since they do not notice that it is not preforming as well as it used to. If they did half of what is recommended, it would last much longer. The trouble is if you do not maintain a tankless unit you will see a fall off water pressure, and or how hot the water actual gets.

[Ladiesman271]

Did you take the course? Also did you take any of the tankless water heater courses. I have and I have the certificates to prove it. My point of my little rant is most people do not do the maintenance required on a tanked heater mainly since they do not notice that it is not preforming as well as it used to. If they did half of what is recommended, it would last much longer. The trouble is if you do not maintain a tankless unit you will see a fall off water pressure, and or how hot the water actual gets.



Yes, but can anyone afford to have a professional do regular maintenance on a tank type water heater? That tank deliming procedure is kind of dangerous for a DIYer!

For that matter, does anyone do any maintenance on a tank water heater unless it does not work at all? Out of site and out of mind? It is probably just cheaper to replace the tank every ten years than to pay to have PM performed on a regular basis.


Yes, if you want a tankless heater to last 20 years delime it on an annual basis!

[SewerRatz]

Yes, but can anyone afford to have a professional do regular maintenance on a tank type water heater? That tank deliming procedure is kind of dangerous for a DIYer!

For that matter, does anyone do any maintenance on a tank water heater unless it does not work at all? Out of site and out of mind? It is probably just cheaper to replace the tank every ten years than to pay to have PM performed on a regular basis.


Yes, if you want a tankless heater to last 20 years delime it on an annual basis!

Was the first yes that you took the A.O. Smith course?

All un-lime is phosphoric acid solution, same stuff in your soda pop. As long as you remove the anode rod deliming it is a whole lot easer than some of these projects these DIYers take on. The instructions for deliming a tank heater is real easy to follow. http://www.hotwater.com/lit/training/4800r9.pdf

[Ladiesman271]

Was the first yes that you took the A.O. Smith course?

All un-lime is phosphoric acid solution, same stuff in your soda pop. As long as you remove the anode rod deliming it is a whole lot easer than some of these projects these DIYers take on. The instructions for deliming a tank heater is real easy to follow. http://www.hotwater.com/lit/training/4800r9.pdf



That's the same link that I used in my post above. Too bad those anode rods do not come out that easy, and you do need some clearance above the heater to get the anode out of the tank.


Any homeowner can descale a tankless with little effort and for little cost. No need to call in a professional to do a descale on a tankless.


My basic point was all water heaters require routine maintenance. I have no objection to the use of either a tank or tankless water heater!

[SewerRatz]

And my point is a tanked heater with out the maintenance still provides water pressure and hot water. The thing is it may fail prematurely and consume more energy to keep the water hot when it has not been maintained. Where as a tankless that is not maintained people will notice the water is not as hot, or the pressure gets really low.

[nhmaster]

I have a 40 gallon AO Smith electric water heater that has been running continuously for over 15 years now with ZERO maintainance, not even an element. And that is not unusual for water heaters at all. Hardly anyone ever services them with the exception of changing elements. Original cost of the tank, around 150 dollars back then.
Though you probably should do periodic maintainance on them, mos folks never do. They will not get away with the same careless attitude with their tankless.

[Redwood]

Yes, but can anyone afford to have a professional do regular maintenance on a tank type water heater?

What's that matter to you?
You couldn't even afford to have your tankless installed by a pro in a state that has laws prohibiting DIYer Plumbing in addition to voiding your manufacturers warrantee...

That is why I install Bradford White Hydrojet Water Heaters...


What is the difference between the Hydrojet® and other cold water inlet tubes?
Unlike a conventional dip tube where the water exits with weak diffusing action, water exits the Hydrojet® system in complete turbulence. This turbulence provides more efficient mixing, yielding the following benefits:

Water heaters with the Hydrojet® system don't have to work as hard or as often to maintain a maximum supply of hot water at the desired temperature.
The resulting decrease in energy consumption saves you money.
The turbulent action also puts sediment (lime, minerals) into suspension, cleaning the tank of harmful deposits every time there's a call for hot water.
http://www.bradfordwhite.com/faqs.asp#question8

[STyler]

For those of you who own them, it's VERY simple to do, no parts to be removed - they get cleaned as well, plug & leave, come back an hour later and thats it.
Nothing complicated, no serious issues, just a small pump with two double ended washing machine hoses connect the the cold inlet draw-off, close the cold valve and let it circulate the vinegar through the hot draw-off through a 5 gallon bucket while you get on with life for an hour or so.

Can you explain with a little more detail (for a novice) how the unit should be plumbed to accommodate the process the easiest? I was planning on going from Pex > ball valve > Flex WH pipe > Cold Inlet. Is the "draw off" a "T" after the valve with a another ball valve that terminates to nothing (to be tapped into for the flush)?

... and then the exact same setup on the Hot Water outlet?