Maintenance of hot water heaters

Everything in your home will last longer if it is well cared for and properly maintained. There usually isn't much that you can do to preserve and extend the life of your hot water heater, other than use it according to the manufacturer's instructions. However here are a few tips that might help.

Just remember that different types of heaters and geysers operate in different ways, so if you are in any doubt whatsoever, rather call in a professional plumber to assist you. In any case, most countries have legislation that specifies only the pros may do repairs and active maintenance work on hot water heaters. Certainly, only a qualified plumber should install a hot water heater in your home.

How to avoid unnecessary deterioration of your cylinder

Some hot water heaters deteriorate more rapidly than others, depending on what they are made of.

When sediment builds up inside the heater it sometimes gets trapped. If this happens (which it can do, particularly in older model cylinders), it can prevent efficient heat transfer to the water. Instead it will tend to leak up through the vent or flue, wasting energy and minimizing efficiency. You may not even realize this is happening, although if you hear a rumbling-type sound, it may indicate the presence of a sediment build-up.

While most hot water heaters manufactured today incorporate features that limit and even stop sediment from building up, if yours is an older model, it's a good idea to regularly drain the water heater. This will have the effect of flushing out any sediment that has built up (see below). Sediment and rust often go hand-in-hand, and so it is always wise to keep an eye out for rust. You'll pick this up when you fill a bath or ceramic basin with hot water. If you do notice that the water appears a bit dirty – usually slightly orange – then call in a plumber immediately. Hot water heaters do sometimes split when they rust! Rather have it checked out and if necessary, replace the heater.

How to drain and flush-out a hot water tank

First and foremost, NEVER flush out your tank or cylinder with hot water. First turn off the power (be it electricity or gas) and allow the water to cool.

When the water from the hot tap runs cold, close the inlet valve (so no water can flow into the tank) and attach a suitable flexible rubber or plastic hose to the outlet valve, ensuring the water can escape into the garden or down a drain. Now turn on a hot tap in the house (this will allow air to enter and ensure there isn't a pressure build up), and then open the valve to drain the water.

Once the tank is empty, open the inlet valve and flush the tank. Continue turning the cold water valve on and off until the water coming out of the tank is clear and clean. If the cold water is still dirty, there is probably a problem with the quality of the water supply. This sometimes happens during very heavy rain or flooding.

Refill the tank fully before turning the power back on.

Check that your hot water heating system incorporates the correct valves

Pressure reducing valves are used to control the inlet water pressure entering a hot water heater. If there is too much pressure in the cylinder, it may split, in which case you will need to have it replaced.

If you are having a new unit installed, check that your plumber has installed the valve. If you buy an older home and inherit an old cylinder that doesn't incorporate this valve, call in a plumber to check the unit and see if one should be fitted. It will, as mentioned previously, depend on the type of hot water heater you are using.

Another type of valve that is commonly used within a hot water heating system is a tempering valve which stops the water going above a specific temperature. In fact in many countries, all new installations and replacement heaters must incorporate a tempering valve. So check on this too.

A tray under your cylinder will minimize possible water damage

It is a fact of life that sometimes hot water cylinders leak, particularly if they are not properly maintained. In the event of a leak, a tray installed under the cylinder will catch any drops and thus prevent unnecessary water damage to carpets and the like.

Just be aware that if the cylinder is not properly maintained and it splits, or worse still bursts, a tray is not going to contain the water flow from the cylinder. This is why it is so essential to keep it clean and well maintained.