Changing The Sacrificial Anode

Types Of Hot Water Systems

Not all 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 showering.

There 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 sizes.

Most RV’s 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 RV’s prior to switching the gas unit switch on.

How To Change A Sacrificial Anode

For 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 step.

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.

Tools/Equipment Required

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

4. 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 water tank.

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.

9. “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 for heating.

11. Clean up and then order another anode as a spare.

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