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  1. How to make your new tank-style water heater last "forever"

  2. Tankless water heaters and their maintenance

How to Make Your NEW Tank-style Water Heater Last “Forever”
-Or extend the life of your existing one-

Well, nothing is “forever”.  But forever can be relative – such as lasting a lifetime.  And I emphasize “new” water heater here because you want to start this maintenance with a new tank-style water heater in order to get it to last a lifetime.  However, if you have an existing tank-style water heater, you can still extend the life of that unit by following this maintenance methodology.  I will address tankless-style water heaters in a future article.

 

The two primary issues affecting the life expectancy of your traditional tank-style water heater are:

  1. Buildup of sediment inside the tank

  2. Corrosion of the tank and plumbing connections

 

The first issue negatively impacts the efficiency and capacity of your water heater.  The second issue leads to catastrophic failure of the heater, along with the damage of the associated flooding.  By addressing these two primary causal factors of failure, we can extend the life of the unit.

 

A quick overview of how we address these issues:

  1. Flush water heater tank annually

  2. Replace the anode rod every five years

 

 

WATER HEATER TANK SEDIMENT BUILD-UP

 

Unless you are using a water softener, the water entering your tank likely has many dissolved salts in it.  The common term for this is TDS – Total Dissolved Solids.  Inorganic salts and some organic matter make up the TDS.  Many people refer to this as the “hardness” of the water.  The higher the TDS, the harder the water.  Hard water is very common here in Norther Virginia.

 

The dissolved salts “precipitate” out of solution under the heating and cooling, as well as pressure, inside your tank.  By precipitate, we mean they form back into insoluble solids and create scale and sediment in your tank.  You can see this in action in a coffee maker or tea kettle in use over time.

 

The efficiency and capacity of the water heater is reduced as this sediment builds up on the bottom and sides of your water heater.  Additionally, the buildup at the bottom of a gas water heater creates a layer of insulation where the gas flames heat the water.  The heater must fire for longer periods to achieve the thermostat temperature setting.  This puts excess heating and stress on the metal at the bottom of your tank.  In an electric water heater, the sediment may eventually cover the lower heating element and cause the element to fail prematurely.  Lastly, when the buildup is severe at the bottom of a the tank, the water entrapped in this sediment  is heated to the point of boiling and pockets of “air bubbles” (actually water vapor bubbles) can emerge violently out of the sediment, causing loud pops that can be quite disconcerting to hear.

 

For a very visual example of how much sediment can build up and what it looks like (it looks like wet sand), please check out this video: 

https://www.youtube.com/watch?v=kAzKts6Wp1Q  (skip to the 0:50 mark to bypass some silliness).

Addressing the sediment problem

 

The basic solution is to flush the tank annually, and some even suggest doing it twice a year.  I would say it all depends on the “hardness” of your water - the more TDS, the harder the water.  There is a procedure to properly flush your water heater tank.  But before I get into that, I need to address the concern of the tank drain valve. 

 

Many, if not most, water heaters have a gate-type drain valve, and perhaps plastic parts – such as the knob.  The problem with gate valves is twofold.  They constrict the flow of water and are thus prone to blockage.  They also tend to leak if the packing nut is not tight, or if the gate encounters sediment on closing.  The issue with the plastic knob is that they become brittle with age and heat and can break off.  Not ideal when you are actively draining 40 gallons of water. 

 

The solution is to replace the tank drain with the proper ball valve.  I strongly recommend this be done by a licensed plumber, because a plumber will install the correct fittings to prevent corrosion and leaks.  A ball valve is the type that has a lever.  When the lever is parallel to the pipe, water is flowing.  When the lever is 90 degrees from that – i.e. perpendicular to the pipe – water is shut off.  The advantages to these types of valves is that they do not constrict water flow (the inside diameter is the same as the pipe), and they are unlikely to develop a dripping leak.

 

Tank flush

 

There are several good videos on YouTube on how to flush your water heater tank.  Here is one:

https://www.youtube.com/watch?v=6nZjHTX91ZQ

 

If you prefer a written step-by-step method, please proceed to the addendum at the end of this article.

 

WATER HEATER CORROSION

 

Water heater tanks come with something called an “anode”.  You may even see this labeled on the top of your water heater.  Technically, this is a sacrificial metal anode to protect against galvanic corrosion.   If you are a boater, then you are probably already familiar with this concept.  This anode sacrifices itself and corrodes so that the metal tank and fittings do not. 

 

The anode is a long metallic rod a bit shorter than the height of the tank.  Depending on a number of factors, these anode rods will last about five years.  After the anode has fully sacrificed itself and is completely corroded, guess what starts to corrode next?  Yup – the water heater tank and/or fittings.  Again, depending on a number of factors, the water heater tank will eventually corrode through after five years or more.  This is why the average life expectancy of a water heater is 10 to 12 years. 

 

When a water heater fails in this manner, water will be coming out of the unit at the same pressure as your water supply.  That is A LOT of water.  Imagine tossing the end of your outside garden hose through your window into your house and turning it on for 10 minutes.  Imagine doing it for 8 hours.  No thank you!

Replacing your anode rod

 

The general rule of thumb is to replace your anode rod every five (5) years.  If you begin to get a strong sulfur smell from your hot water, it may be an indication that your anode rod needs to be replaced – but do not wait for this to occur because it may or may not happen.  Like the water heater drain gate valve replacement, I strongly recommend the anode rod replacement be performed by a licensed plumber.  However, if you are extremely handy, you can find several good YouTube videos that show you how it is done.

 

I will not list the steps for this procedure as I feel a licensed plumber should complete this.  If you choose to do this yourself, proceed at your own risk.  Be very careful as you are dealing with potentially scalding water at pressure.  The anode you remove will also be very hot.  I assume no liability for a DIY job here.

 

One thing to note:  If overhead space is limited (as it often is), there are replacement anode rods that have flexible links between shorter rod lengths that allow them to be inserted into the tank.  Removing the old anode rod may have the same issue with overhead space.  In this case, bending or breaking the old rod may be required.  Just be very careful to make sure that if it breaks, the bottom piece does not fall back down into the water heater – you may end up buying a new water heater if it does!  A replacement anode rod with space restrictions can be purchased and fitted - it looks kind of like sausage links.  Incidentally, replacement anode rods run anywhere from $20 to $100.

 

After the anode rod is replaced, be sure to make a note of this on the side of your water heater.  Using a sharpie to write “anode replaced MM/DD/YY” on the unit just makes sense for your future reference.

 

 

SUMMARY

 

Nothing is forever - but with these maintenance steps, your water heater can almost be.  By draining and flushing your tank annually and replacing the anode rod every five years, you can significantly extend the life of your water heater and help avoid a water heater replacement cost of $600 to $2,000.  Thank you for taking the time to read this article.  I hope it helps to you save some money.  Feel free to contact me with any questions.

 

© 2019 Tim Wiley All Rights Reserved

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ADDENDUM

 

Procedure to flush the water heater tank

 

  1. Turn “off” the water heater.

    • Gas water heater:  Turn the thermostat to the vacation setting, or to the lowest setting.

      • Be sure to note where the thermostat was originally set

    • Electric water heater:  Throw the water heater breaker to OFF in the electrical panel.

  2. Shut-off the cold water supply to the tank.

    • This valve is normally located directly above the water heater on the cold water inlet line.

  3. Connect a garden hose to the water heater drain valve at the bottom of the water heater.

  4. Place the other end of the hose in a floor drain, sump pit (with pump), or other receptacle that allows you to dispose of the water.

    • Make sure no part of the hose or collection point is higher than half the height of the water heater tank.  Otherwise, the water will not flow properly.

  5. Go to the nearest hot water faucet and open it.

    • Water should not flow out since you shut off the water (and thus the water pressure) to the tank in the first step.

      • If water does flow out under pressure, then you didn’t shut off the correct valve.

    • This open faucet will now serve as an air vent to allow the water from the tank to drain.

    • NOTE:  I do not recommend opening the water heater TPR valve (temperature pressure relief) on the top or side of the tank as a vent.  These tend to leak or drip after being manually opened.

  6. Open the drain valve to the water heater

    • Be VERY CAREFUL – the water temperature can cause scalding burns.  The hose will become hot (use gloves).  Make sure no one is splashed by the hot water coming from the hose.

    • Water should flow out of the connected garden hose into your receiving point.  If it does not, double check the previous steps.

  7. Drain approximately half the water out of your tank.

    • You can tell if half the water is drained by lifting the discharge end of the hose to half the height of the water heater.  If the flow stops, then it is halfway drained.

    • Do NOT completely empty the water heater

      • You will likely clog the water heater tank drain.

      • If it is a gas heater, the flame may come on and damage the tank if there is insufficient water in it.

  8. Turn the water heater cold water inlet valve back on

    1. This will begin to agitate the water in the tank and loosen the scale and buildup

    2. More water will start to exit the drain hose – and you should begin to see sediment or discoloration in the discharge water.

  9. Let the water drain from the hose until it starts to run clear – or a minimum of 5 minutes.

  10. After the drain water runs clear, turn the water heater drain valve OFF.

    • Your water heater will now start to refill with water.

    • You know your water heater is completely refilled when water starts running out of the hot water faucet you opened as  an air vent

  11. Turn the hot water faucet off after it has water running out of it.

  12. Remove the drain hose

  13. Turn the water heater back “on”

    • Gas water heater:  turn the thermostat back to where it was set

    • Electric water heater: throw the breaker in the panel back to the ON position

  14. Done!

 

 

© 2019 Tim Wiley All Rights Reserved

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Tankless Water Heaters and their Maintenance

Tankless water heaters have four main advantages:

  1. They generally last longer than conventional tank-style water heaters (20-30 years vs 10-15 years for tank-style)

  2. Higher efficiency:  They do not waste energy keeping water hot during idle times

  3. You will never “run out” of hot water (unless of course you lose your energy source)

  4. They take up considerably less space than conventional water heaters

 

However, the initial cost may be significantly more expensive.  And in the end, you may only break-even on the increased cost vs energy savings, if at all.  It is frankly a personal decision about what is important to you and what your needs are.

 

Most tankless units use gas for heating the water due to the extremely high BTU input required to quickly transfer energy to the water in the heat exchanger pipes of the unit.  Electric models do exist and there is generally no difference in operational costs.  However, electric tankless water heaters require a lot of electrical capacity.  These units commonly need 150 Amps at 240 Volts.  For some homes, that is their entire electrical service.  So expect to pay a lot of money for electrical work.  You may need to increase your service capacity.  And you will need to run a very high amperage double circuit to the water heater.

 

Even though they last nearly twice as long as conventional tank-style water heaters, tankless heaters still need periodic maintenance.  In fact, my opinion is that they require annual maintenance.  The primary issues affecting the performance of your tankless water heater are the buildup of scale inside the heat exchanger plumbing, and any accumulation of debris on the cold-water inlet filter.  Scale is the result of the dissolved minerals in hard water coming out of solution.  The hardness of your water will affect how quickly this scale builds up. 

 

For this maintenance, your system should be installed with two service valves; one at the cold water input and one at the hot water output of your water heater.

 

See the diagram to the right for examples of hot and cold service valves.

(diagram from Rheem Manufacturing)

 

By performing the following annual maintenance, you should avoid most issues with your tankless water heater:

 

  1. Clean the combustion air intake filter (if installed)

  2. Drain the internal plumbing of the water heater

  3. Remove, clean, and then reinstall the cold-water inlet filter

  4. Flush the internal plumbing of the water heater to clear it with a descaling kit

 

Before we talk about the annual maintenance in more detail, there is maintenance task recommended for tank-style units that is not required for most tankless units.  Most (if not all) tankless water heaters do not have a sacrificial anode rod that needs replacement every five to six years.  Tankless units have no anode rod because there is no tank that needs protection from corrosion.

ANNUAL MAINTENANCE

 

For all of the steps above, I recommend following the manufacturer’s maintenance instructions of your tankless water heater manufacturer.  For step #4, Flushing the internal plumbing, you will also need to follow the instructions of the kit manufacturer.  I also provide a summary of this procedure below.

 

Water heater flush

 

The purpose of using the flush kit is to remove the built-up of scale inside the heat exchanger plumbing of your tankless water heater.  This is accomplished by circulating a weak acid solution through the system for a short period of time (about 45 minutes) to dissolve the scale inside the pipes.  Be sure to put this recurring annual maintenance in your electronic calendar or task/reminders list.

 

Please see the addendum below for an idea of the general step-by-step procedure to flush the water heater.

 

Flush kits

These kits run from $120 to $180 and are required to perform this annual maintenance.  After you have made the initial investment, all you need in the future is the acidic descaler solution that costs about $25.  You can search for a flush kit on the internet that meets your needs.  Here are two examples:

Home Depot:

https://www.homedepot.com/p/Eccotemp-Eccotemp-EZ-Flush-System-350-GPH-Pump-NSF-ANSI-60-Certified-Descaler-Kit-EZKIT/301356674

 

Amazon:

https://smile.amazon.com/Whitlam-FLOW-KIT-Flow-Aide-System-Descaler/dp/B00E5P5VYG/ref=sr_1_2?keywords=tankless+flush+kit&qid=1573358932&sr=8-2

 

Videos

There are also several informative videos on YouTube on how to flush your tankless water heater.  I really like Matt Risinger’s channel.  Here is one he posted:

https://www.youtube.com/watch?v=znuACzzav_Y

 

Example diagram of a tankless heater flush kit setup:
 

V1=hot water shutoff, V2=cold water shutoff, V3=hot water service valve, V4=cold water service valve.  D1,2,3= supply and return hoses with circulation pump.  (diagram from Rheem Manufacturing)

SUMMARY

 

Tankless water heaters offer many advantages, but do not buy one thinking you are going to save money in the long run.  Instead, buy one for reasons of longevity, endless hot water, space saving, or lower carbon footprint.  But even though they last longer, they require descaling at an appropriate interval consistent with your water hardness.  Invest in a descaling kit and you are investing in the worry-free operation of your water heater for years to come.

© 2019 Tim Wiley All Rights Reserved

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ADDENDUM

 

General Procedure to flush a tankless water heater lines
(be sure to follow the instructions of your kit and/or water heater manufacturer)
 

  1. Remove the power to the water heater (unplug it, remove the electrical disconnect, or flip the breaker to off – which ever makes sense for your unit)

  2. Shut off the gas to the unit (disregard if an electric tankless water heater)

  3. Turn off the cold water supply valve to the unit, and turn off the hot water supply valve from the unit

  4. Remove the caps to both flush valves

  5. Connect the hoses from your kit to the flush valves (submersible pump supply to cold, discharge from hot)

  6. Mix the descaler solution with water in the kit supplied bucket as directed by the instructions

  7. Place the submersible pump in the supplied bucket, and place the end of the discharge hose into the bucket as well

  8. Open both of the service valves connected to the unit – one for hot, one for cold

    • Do NOT confuse these with the cold water supply and hot water supply valves!

  9. Plug in the pump and it should start running

  10. Check that the solution is coming out of the discharge hose after 15 seconds or so

  11. Run the pump with the solution through it for 45 minutes

    • This is the descaling part of the operation

  12. After 45 minutes, unplug the pump

  13. Disconnect only the kit supply side hose (the one with the pump) and replace the cap on the cold water flush valve

  14. Turn off the service valve on the cold water side

  15. Remove the end of the discharge hose from the bucket and direct it to a drain or other place that will handle a large amount of water

    • Note: the kit discharge hose is still connected to the water heater

  16. Open the cold water supply valve to the water heater for two minutes or so to flush the unit out

    • The unit will not fire because the gas is still off and the unit is unplugged

    • The purpose of this is to clear the pipes of any loose scale that may be remaining

  17. After two minutes, shut the cold water supply back to off

  18. Remove the discharge hose from the water heater and replace the cap on the hot water flush valve

  19. Turn off the service valve on the hot water side

  20. Confirm that both the hot and cold service valves are off and the caps have been replaced

  21. Open the water heater hot water discharge valve and the water heater cold water inlet valve

  22. Go to a nearby fixture and open the hot side of the faucet

    • Let this run for a minute until any air has blown out of the line, then shut it off

  23. Open the gas valve to the water heater

  24. Plug the water heater back in (or flip the breaker or switch the disconnect to on)

  25. Go to a nearby fixture and open the hot side of the faucet

    • Confirm that the water heater fires up and that hot water start running from the faucet, then turn off

  26. Properly dispose of the descaling solution

  27. Finished!

 

 

© 2019 Tim Wiley All Rights Reserved

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