How to maintain water heaters
A guide to water heater maintenance is provided by DAVID MICALLEF from Rheem.
Water heating systems require little servicing to maintain their performance; however, there are a number of requirements that should be adhered to in order for them to operate efficiently and safely. This quick guide is an overview and does not replace the advice provided in the operations manuals that are supplied with products. Some service items can be performed by the system owner; however, there are some maintenance requirements that should only be undertaken by qualified personnel.
Storage water heaters include those heated by integrated gas burners or electric heating elements, and include storage tanks used with solar, heat pump and external gas heaters. The maintenance requirements of all storage tanks are similar and include completing the following every six months:
- Operate the easing lever on the temperature pressure relief (TPR) valve and the expansion control valve (ECV), if one is fitted. It is very important to raise and lower the lever gently. Exercise care to avoid any splashing of water, as water discharged from the drain line will be hot. Stand clear of the drain line’s point of discharge when operating the valve’s lever.
- Check that the drain line from the safe tray is not blocked, if one is installed.
The annual service requirements for a water heater include the following:
- inspect and flush the TPR
- inspect and flush the ECV, and
- inspect all connections.
In addition, for gas and electric models, the following maintenance procedures should be performed:
- check and, if necessary, adjust the inlet gas pressure
- check the operation of and clean the main burner
- check the operation of electric elements and thermostats
- in hard water areas, check for excessive build-up of lime scale on the heating elements, and
- visually check the unit for any potential problems.
MAJOR FIVE-YEAR SERVICE
It is recommended that a major five-year service be conducted on the water heater, which includes the following actions:
- replace the TPR
- inspect and flush the ECV and, if required, replace the valve
- inspect and, if required, replace the anodes in vitreous enamel lined tanks (if the anodes are not replaced, they should be replaced within three years of this service), and
- drain and flush the water heater, if required.
In commercial applications, where large volumes of hot water are used, sediment may build up on the bottom of the cylinder and reduce the heating efficiency. In extreme cases, particularly in areas of high water sediment, draining and flushing out may be necessary.
CONTINUOUS FLOW WATER HEATERS
Continuous flow water heaters (CFWH) require the following routine maintenance every six months:
- Inspect around the air inlet, flue terminal and the water heater in general for plant growth. Trim back any shrubs, bushes or other plants that are encroaching on the water heater.
- Inspect around the water heater for insect infestations, such as ants, and have them treated. Insects encroaching into or nesting in the water heater can interfere with the operation of the water heater and damage components.
- Check and clean line strainers on the cold water inlet and hot water return, and the filter on the CFWH cold water inlet.
Annual CFWH maintenance procedures include:
- check and, if necessary, adjust the gas pressure
- check the operation of and clean the burner
- visually check the unit for any potential problems, and
- inspect all connections.
SOLAR WATER HEATERS
For solar water heaters, all actions relating to storage tanks should be observed. In addition:
- clean the glass on the solar collectors as necessary, especially in dusty environments or where birds may foul the glass
- check operation of the pump, and
- for heat exchange systems, check the level and pH of the heat exchange fluid annually.
David Micallef is the technical marketing manager at Rheem Australia.