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Hot Water System Maintenance

RMC Plumbing Services are aware that your gas storage hot water system will make some noise whilst heating this is normal.

But! When your gas storage hot water system starts popping and banging it is telling you that it really needs servicing.

What needs servicing on a gas storage hot water system?

  1. Every 3 to 5 years the sacrificial anode inside your hot water system cylinder needs replacing! Unfortunately the water supply in the South West is hard water that is sourced from a bore. When heated it can become corrosive as well as mixed with Chlorine is a harsh combination. (some hot water systems have 2 anodes)

  2. Replacing the cold water expansion valve on the water inlet every 5 years (this valve protects the cylinder from over pressure whilst heating).

  3. Replacing the hot water temperature relief valve every 5 years.(this safety valve which is set to protect the hot water cylinder from over temperature if the temperature exceeds 98’ C.

  4. Removal and cleaning of main burner and pilot flame assembly.


When the anode/anodes are replaced the hot water cylinder is drained and the bottom of the hot water cylinder is flushed out with clean water to ensure all residue from the old anodes is cleaned out from the cylinder. The hot water system is fitted with new anode/anodes and re-filled and put back into service.

Hot water heater Sacrificial Anode Replacements

Electric storage hot water systems and heat pumps

These hot water systems only have the anode replacement as part of their service.

Gas Instantaneous Hot Water Systems


The main manufacturer of these systems are Bosch with some Rinnai and other brands on the market. The main appliance we get to service is the Bosch 10 pilot or Hydro.


When these particular hot water systems need servicing you will know as you simply lose hot water temperature.

Tempering Valves


Generally servicing involves replacing the diaphragm rubber and o rings inside the water section and the hot water system is back to where it was.

RMC Plumbing Services wish to advise that all bathrooms must be protected from receiving scalding hot water which can cause severe burns to the elderly or infirm, also the possibility of burns to children.

The temperature protection is achieved through a tempering valve which must be fitted (minimum to any bathroom) . Kitchen and Laundry can receive hot water above 50’ Celsius.

Unfortunately with our poor water quality some times the tempering valves can seize and not mix hot and cold water effectively therefore you would only receive luke warm water. If this is the case the tempering valve will need to be replaced as they are a consumable item.

Tempering Valve maintenance

Rory, Scott & our friendly plumbing team are just a phone call away 0412 287 673

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