Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013
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).
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
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.
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
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.
If initial inspection after 6 months shows 1/2" of lime
accumulation. Therefore, the heater should be delimed once
If initial inspection after 6 months shows 2" of lime accumulation.
Therefore, the heater should be delimed every 3 months.
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
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.
Last edited by Ladiesman271; 02-17-2009 at 06:16 AM.
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!
Samuel James Witwicky
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!
Samuel James Witwicky
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.
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.
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.
... and then the exact same setup on the Hot Water outlet?