How to Change a Sacrificial Anode
What is a sacrificial anode?
What brands of hot water systems have sacrificial anodes?
How to know when to change the sacrificial anode in a caravan hot water
tools are required to change the sacrificial anode in a caravan hot water
Types of Hot Water Systems
caravans, campervans or RVs come with a hot water system/hot
water heater. If the caravan, motorhome, campervan,
camper trailer or
RV does not have a hot water heater then you need to boil
the jug (electricity) or kettle (gas) for washing up and
are two main types of hot water heaters ie: storage and
continuous or tankless. Storage hot water systems hold hot
water in a tank where continuous (or instant/tankless)
systems heat the water as it passes through a heater. The
hot water heater storage tanks are available in various
RVís have the storage type hot water heater. These storage
type hot water heaters operate on mains power or LPG gas.
If operating on gas, you must remove the gas cover or cowl
located on the outside of some of the earlier model RVís
prior to switching the gas unit switch on.
How To Change a Sacrificial Anode
those caravans, fifth-wheelers and motorhomes with a
Surburban Hot Water System a replacement of the sacrificial
anode will be required at some time. The storage tank in
this hot water system is protected by a magnesium or
aluminium anode to prolong the life of the tank. The anode
should be checked every 6 months and replaced if below 50%
of original diameter.
To extend anode life, drain water from the
tank whenever your caravan, fifth-wheeler or motorhomes is
not in use BUT be sure to refill the HWS storage tank with
water before use.
An 'Operating Instruction Manual' should have
been provided with the appliance so refer to it as a first
A sacrificial anode can be purchased at RV
stores or on-line stores but check the model number of your
HWS before ordering as some anode dimensions do vary. The
'Operating Instruction Manual' states - to prevent a water
leak when replacing the anode, a pipe thread sealant
approved for potable water (such as Teflon Tape) must be
applied to the threads of the anode rod.
If you are not confident you can do this
anode replacement yourself seek out a caravan or RV service
centre to do it for you.
Gas/Electric Hot Water System Cover
Showing the anode once the cover is removed.
Anode Rod (Suburban Magnesium Anode
Rod# Part No: 232767)
Teflon thread sealant tape
1-1/16" diameter wrench socket
Turn Off Water Heater
1. Turn water heater switch to off
2. Turn off electrical power to the appliance
3. Turn off gas supply (gas cylinder/bottle)
NOTE: For safety reasons, turn the water
heater off the night before to let the hot water in the
storage tank 'cool' first to avoid any chance of scalding
from hot water before proceeding with the following steps -
Replacing the Sacrificial Anode
Wrap top of new anode in a clockwise direction thread with
sealant tape. Don't put the sealant tape on too thick or you
will have difficulty tightening the anode. Have the wrench
and socket close at hand.
5. Turn off the water pump inside the RV/
turn off town water - then turn the water tap in sink to
'hot' water and let run out as this depressurises the hot
6. Attach the socket wrench to the anode top
and unscrew (counter clockwise) and remove the anode. Water
(may include some coloured gunk - you may want to place a
bucket underneath to catch this) will pour out so stand back
and be careful to avoid scalding. Let the water heater tank
drain out. Then, using another hose connected to mains
water, inset it into the tank to flush out any sediments. Shut off the 'hot' water tap inside the
RV and turn the water pump back on waiting until the water
flowing outside is clear.
7. As soon as water is clear, turn off the
water pump, and then insert the new anode and tighten
(clockwise). The anode may not tighten all the way to end of
thread. Do not over-tighten.
8. Turn on one 'hot' water tap and the water
pump in RV. Be patient and wait as the water is re-filling the hot
water storage tank. Once it is full, water will come
through the hot water tap. Turn the tap off.
"Bleed" the air out of the HWS storage tank by lifting the
small valve handle outside on the appliance until the water
flows out continuously. Check the unit for any water leaks.
10. Unit is then ready to turn on power/gas
11. Clean up and then order another anode as