Water Heaters
Diagnosing hot water faults, servicing storage and tankless units, and sizing replacements against real demand.
Hot water complaints fall into a few groups: none at all, not enough, not hot enough, too hot, or hot water that arrives with noise, discolouration or smell. Each group points at a different part of the system, such as the heat source, controls, storage, or the distribution pipework between the unit and the outlet.
Water heating equipment also has a maintenance life. Sediment, scale and anode depletion in storage units, and scale in tankless heat exchangers, reduce output long before a unit fails outright.
Symptoms
Signs this is the right service
- Hot water runs out faster than it used to
- Water arrives lukewarm however the thermostat is set
- Rumbling, popping or kettling noises from a storage cylinder
- Rusty or cloudy hot water that clears when the cold tap is used
- Moisture, corrosion or staining around the base or connections of the unit
What the work covers
Methods and scope
Which method applies depends on what the system is doing, the materials involved and the condition of the pipework.
- Fault diagnosis
- Checking the heat source, thermostats, elements or burner, safety cut-outs, and the mixing and distribution arrangement, because a lukewarm outlet can be caused by a mixing valve rather than the heater itself.
- Servicing and descaling
- Flushing sediment from storage tanks, inspecting or replacing sacrificial anodes, checking pressure relief devices and expansion provision, and descaling tankless heat exchangers in hard water areas.
- Repair versus replacement
- A failed thermostat, element, valve or control board is usually a repair. A leaking tank, a heavily corroded vessel or a unit that is undersized for current demand is a replacement decision.
- Sizing and selection
- Storage units are sized on peak demand and recovery rate; tankless units on simultaneous flow and the temperature rise required from the incoming supply. Fixture counts and usage patterns drive both.
Process
How the work is sequenced
Confirm the symptom precisely
No hot water, insufficient duration, and inadequate temperature are three different faults with different likely causes.
Check controls and safety devices
Thermostats, cut-outs and relief valves are inspected before any conclusion about the vessel or heat exchanger.
Assess the vessel or exchanger
Sediment level, scale, anode condition and corrosion determine remaining service life.
Present the options
Where both repair and replacement are viable, the difference in expected life and running cost is set out so the choice is informed.
Commission and set up
New or repaired units are set to a safe delivery temperature and the relief and expansion arrangements are verified.
Questions