The most common caravan & RV Hot Water System (HWS) used in Australia is the Suburban. These gas and electric hotwater systems require some simple maintenance. You should inspect them every 6 months or before a big trip.
Video Guide to Suburban Maintenance in 3 mins
What is an Anode?
Suburban Heaters are fitted with a sacrificial anode. The water in Hot Water Systems is slightly corrosive. The job of the anode rod is to protect the metal inner tank. The anode is made of a softer metal than the tank and so redirects the corrosion. Because the annodes are intended to corrode they need to be inspected / replaced periodically.
1. How to Inspect / Replace an Anode Rod
Before trying to inspect the anode make sure your Hot Water System has been turned off long enough to cool down. The water will drain out when you remove the anode.
1) Switch of the HWS and disconnect 240 volt power to the caravan.
2) Turn off the gas supply at the bottle.
3) Turn off the 12 volt pump.
4) Disconnect mains pressure water from the caravan.
5) Turn on your taps to release any pressure.
6) Open the pressure relief valve.
7) Remove anode with a tube spanner (below).
8) Flush and rinse the tank.
9) Install new anode if needed.
10) Refill the tank before turning on.
To remove the anode you will need a 27mm socket or 1 1/16" tube spanner, don't forget you will need some pipe thread tape. The anode is located near the bottom below the burner tube. Using the tube spanner loosen the anode remember this is going to allow the water to drain from the tank. Removed the anode and inspect, it is recommended to replace anode if it is less than 50% of original diameter.
If you are inspecting the anode it is a great idea to flush and rinse your tank before you close it up. You will be surprised at the amount of muck that accumulates in your drinking water. The correct method to drain the hot water system is by removing the anode as described above.
You can flush the tank by sticking a garden hose inside the tank. The hose method is better than nothing but it is hard to get enough pressure to clean it properly. The Camco Rinser attaches to a hose and does a much better job.
All electric Suburban Water Heaters are fitted with a 1440watt / 240volt element. This element has been updated from the original design but will still fit older units. The new design increases the surface area of the element producing a more efficient and quieter system. As the unit ages it is common for calcium build-up to develop on the element, this can lead to an increase in noise level and recovery time.
3. How to Inspect / Replace an Element
Before starting any maintenance work on Suburban water heaters ensure you have disconnected all forms of electricity and gas.
You will find the element under a protective cover. For combined gas/electric units this is located behind the main burner tube.
1) Use the Anode Removal Section to drain the tank.
2) Using a small spanner you will be able to disconnect and remove the burner tube giving easy access to the element cover.
3) Remove the cover by unscrewing the 2 or 3 holding screws to expose the element.
4) Remove the 2 x 240 volt wires from the Element head using a philips head screwdriver.
5) Flush and rinse the tank.
6) Remove and Inspect the element. Speciality 1 1/2 inch tube spanner required (below).
7) Install the new element so that the final position of metal terminals are horizontal.
8) Reconnect the 2 x 240 volt wires. Polarity not important.
9) Replace plastic cover and reconnect burner tube.
10) Refill the tank before turning on.
Gas models of the Suburban Heaters have a gas burner tube which needs to be cleaned periodically. The burner tube is susceptible to cobwebs, rust and other debris which will stop it working efficiently. A yellow flame is a sign that things need a clean. Use a toothbrush and compressed air to clean the burner tube. It is rare that they need to be fully replaced.