How hard water ages a tank
La Mirada's water is hard, a blend of local groundwater and imported supply. When water is heated, some of those minerals settle to the bottom of the tank as sediment. On a gas heater the burner has to push heat through that layer, which causes popping and rumbling and stresses the steel. Scale also builds up on valves and heating elements.
Inside every steel tank is an anode rod that corrodes so the tank does not. Once the rod is used up, the tank itself starts to rust. A tank that leaks from the body or the bottom seam is past repair, but many other symptoms come from parts that can be replaced.
Symptoms and what they usually mean
| Symptom | Common cause | Usually |
|---|---|---|
| No hot water on a gas unit | Pilot out, thermocouple or flame sensor, gas valve | Repairable |
| No hot water on an electric unit | Tripped breaker, failed element or thermostat | Repairable |
| Popping or rumbling | Sediment on the tank bottom | Flushing may help; often a sign of age |
| Rusty hot water only | Depleted anode rod or internal corrosion | Anode may help on a younger tank |
| Water dripping from the relief valve pipe | High pressure, high temperature or a worn relief valve | Diagnose before replacing the valve |
| Water leaking from the tank body | Corroded tank | Replace |
Repair or replace?
- IfThe tank is leakingThenReplace. Close the cold inlet and turn the gas to off or the breaker off in the meantime.
- IfA single part failed on a fairly young heaterThenRepair is usually reasonable.
- IfThe heater is older, noisy and has needed several repairsThenReplacement is often the better value.
- IfThe venting, gas connector or strapping is out of dateThenFactor the cost of bringing them up to standard into the decision.
- IfYou want more hot water or lower standby lossesThenAsk about a larger tank, a high-efficiency tank or a tankless unit.
What a proper replacement includes
- Seismic straps or bracing, which California requires on water heaters.
- A temperature and pressure relief valve with a discharge pipe routed to an approved location.
- Correct venting for the unit, with proper clearances and slope.
- A new flexible gas connector and sediment trap where required.
- An expansion tank if the system is closed, for example by a pressure regulator.
- Platform height or other protections required in a garage installation.
- A permit and inspection where the city requires one.
Questions to ask before replacing
- Is this a repairable part, or is the tank itself failing?
- Will the new heater be strapped, vented and connected to current code?
- Do I need an expansion tank?
- Who pulls the permit and arranges the inspection?
- What happens to the old heater?
Common questions
Should I flush my water heater?
Many manufacturers recommend periodic flushing to reduce sediment. On an old tank that has never been flushed, ask a plumber first, since disturbing heavy sediment can cause the drain valve to leak.
Is a dripping relief valve dangerous?
It is a sign the valve opened or is worn. Do not plug or cap it. Have the cause checked, since high pressure or temperature is a safety issue.
Does replacing a water heater need a permit?
Water heater replacements commonly need a permit and inspection. Check with the City of La Mirada or ask your contractor to confirm.
General information for La Mirada, not a quote or professional advice. In an emergency, call 911.