Don’t forget the Sacrifical Anode

Rob Driver · Guru

Don’t forget the Sacrifical Anode

Mike Harding · Guru

More detail please?

My van is 12 months old and I am about to replace the sacrificial anode but I do not have access to flushing water - do you suggest I should wait until I do?

Warren-Pat_01 · Guru

Hi Mike,
I assume you are not anywhere near a good water source(?). If so I wouldn't touch the anode until you have access to a hose & town water. You might get some zinc residue out, but not all of it. And just refilling the HWS may spread the remainder to places you don't want it to go.
Do the job on a warm day, as you'll get a bit wet too!

Rob x2. I'm certain that 6 months is the perfect "change anode time" as I see the same "wear" in that time

Possum3 · Guru

Whilst there is still some mag alloy on the anode it is still doing it's required job - the anode pictured still has half it's life left. One way to get gunk out of tank is to remove anode without letting the pressure out of tank first ( I did it once) "Ka-blewie" - technical term used by ordinance specialists.

Cupie · Guru

Possum3 wrote:
Whilst there is still some mag alloy on the anode it is still doing it's required job - the anode pictured still has half it's life left. One way to get gunk out of tank is to remove anode without letting the pressure out of tank first ( I did it once) "Ka-blewie" - technical term used by ordinance specialists.

This is exactly my procedure.

I just let the anode blow out & hit the side fence about 600mm away. First time gave me a fright.

I then scrub the anode with a wire brush to remove all the gunk & blow out the bottom of the tank with a special copper pipe hose attachment.

I do it after every trip as part of my mtce routine.

littledick · Senior Member

Yeah, release the pressure first, don't have one in current or previous van.

Dick.

Tony LEE · Guru

RE:

The Kramer · Member

RE: Don’t forget the Sacrifical Anode

Cupie · Guru

The Kramer wrote:
bentaxlebabe wrote:
Twelve months old.
I might bring the service interval to 6 months, after all they are not that expensive and ensure you give it a real good flush out.
I use a brass pipe with a hose fitting on one end and a 90 degree fan nozzle on the other end to flush out the residue. If it is not flushed properly you will have trouble with tap washers and some other bits depending on how your RV / Van is plumbed up.
Regards
Rob

Well they say the only "Dumb Question" is the one you don't ask. So here it is. What is the Sacrificial Anode in? What's its purpose in an RV?

Suburban Hot Water Systems (Perhaps the most common) have a rod (Sacrifical Anode) that is sacrificed by the electrolytic action that takes place in the HWS holding tank. This way the rod deteriorates over time and not the metal tank. If the tank were to eaten away then obviously it would soon leak.

As a matter of maintenance the Sacrificial rod (Anode) must be withdrawn before it becomes too enlarged with gunk (a technical term) or worn through. 3 or 6 months is the normal mtce cycle period but more often if using highly mineralised water like in the WA north.

JayDee · Guru

Possum3 wrote:
Whilst there is still some mag alloy on the anode it is still doing it's required job - the anode pictured still has half it's life left. One way to get gunk out of tank is to remove anode without letting the pressure out of tank first ( I did it once) "Ka-blewie" - technical term used by ordinance specialists.

That is exactly what I do, but stand back unless you want the white stuff all over you. Then with the hose on full pressure, I then place the nuzzle into the open hole and eventually it back force will release the hose nozzle and clean out the tank. Do this procedure several times and all should be ok to replace or install a new anode.

Jay&Dee

Mike Harding · Guru

Thanks Warren and others: excellent advice. I shall wait until I have town water and a hose.

Tony LEE · Guru

RE:

Santa · Guru

RE: Don’t forget the Sacrifical Anode

dorian · Guru

Why is the recommended anode inspection/replacement interval for a domestic HWS around 5 years but only 6 months for an RV?

Iva Biggen · Senior Member

dorian wrote:
Why is the recommended anode inspection/replacement interval for a domestic HWS around 5 years but only 6 months for an RV?

The anode in a domestic water heater is many times larger than the anode in a suburban RV water heater.

My own water heater anode at home was approx four to five feet long.

Cheers

Ivan

Iva Biggen · Senior Member

I think I have noticed also that there is available a smaller anode for the suburban heater and it is a bit cheaper but personally I would not bother.
On another note after reading some of the above posts, I would not recommend allowing the anode to be blown out of the heater under pressure as this practice could damage the thread in the heater body by the force actually breaking the leading edge of the thread and causing difficulty in screwing the new anode back in.
Apart from the damage that practice is just plain dangerous.
Surely it is not that hard to let the pressure out, after all that is how the manufacturers recommend to do it.

To the OP, there is a special tool you can buy which hooks onto the garden hose for flushing but you will be able to flush it with a garden hose without any nozzle by just pushing it in and out of the threaded hole until all the residue is gone and the water runs clear.
Most new anodes these days come with thread tape on the thread but if you get one without tape then you will need to wind a bit onto the thread for sealing. It WILL leak if you dont seal the thread.

Cheers

Ivan

Iva Biggen · Senior Member

Here is a Camco one,

dorian · Guru

Santa wrote:
A tip for those who have a Truma HWS installed, they have a stainless steel tank and don't use a sacrificial anode, so don't tear your hair out looking for this non existent device, you won't find it.

What are the economics of a stainless steel tank versus vitreous enamel, if maintenance costs are included?

Santa · Guru

dorian wrote:
Santa wrote:
A tip for those who have a Truma HWS installed, they have a stainless steel tank and don't use a sacrificial anode, so don't tear your hair out looking for this non existent device, you won't find it.
What are the economics of a stainless steel tank versus vitreous enamel, if maintenance costs are included?

No idea, however my gas electric 14 litre Truma unit is now 13 years old and has been trouble free.

Peter_n_Margaret · Guru

I replaced my Truma HWS at 14 years of faultless operation with a diesel heated calorifier that is copper. Neither require a sacrificial anode.
It should be noted that sacrificial anodes can be various materials and various prices depending on water to be used, life of the anode its effectiveness and its cost.
Known as 'sacrificial anodes', magnesium, zinc and aluminium rods attract the natural ions in water preventing them from causing damage to the interior of the tank (cathode). This is known as the anode protecting the cathode. The corrosion of the magnesium, aluminium and zinc anode is known as galvanic corrosion.

https://www.anodesaus.com.au/applications/hot-water-anodes

Cheers,

Peter

Steel Dog · Veteran Member

Hi All,
Thanks for this valuable information, I never new anything about this anode, after reading your advice I have just change mine today and my JAYCO Conquest is only 18 months old and the anode was in about the same condition as your photo.
I would never have changed it had I not been on this forum, you have definitely saved me a lot of cash and headache.
Thanks again.
Steel Dog

The Kramer · Member

The Kramer wrote:
Well they say the only "Dumb Question" is the one you don't ask. So here it is. What is the Sacrificial Anode in? What's its purpose in an RV?
Suburban Hot Water Systems (Perhaps the most common) have a rod (Sacrifical Anode) that is sacrificed by the electrolytic action that takes place in the HWS holding tank. This way the rod deteriorates over time and not the metal tank. If the tank were to eaten away then obviously it would soon leak.
As a matter of maintenance the Sacrificial rod (Anode) must be withdrawn before it becomes too enlarged with gunk (a technical term) or worn through. 3 or 6 months is the normal mtce cycle period but more often if using highly mineralised water like in the WA north.

__________________
See Ya ... Cupie

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I think I am, therefore, I am ... I think (Geo Carlin)

Thanks for that. Still learning something new each day. :)