Some anode rods are connected to hot water nipple <> read owner's manual <> see list of water heater manufacturers and brands to find manual.
Before starting, close shutoff valve, turn on hot water faucet to relieve pressure, and turn off electricity or gas to heater. Open drain valve near bottom of tank and drain 2 gallons of water what if tank won't drain? Rod will be rusted in place, use generous amount WD-40 <> WD-40 spray is flammable and will burn so be careful around heat source. Loosening rod: go slow and check that water does not seep up when loosening rod because hot water can spew out hole if tank is very hot ... it is important to drain enough water out of tank to avoid accidental scalding.
Install new anode rod: One source says/ use pipe compound on thread instead of teflon tape. Other sources say use teflon tape. Either way, tank metal and anode metal must meet, so rod will work.
Replace
anode rod and extend
life of water heater
When two metals are connected, water reacts with lower noble metal first. Anode rod is made from lower noble metal than steel tank. Water dissolves anode rod instead of rusting water heater.
Once anode rod dissolves, water quickly rusts water heater. Other damage occurs if old anode rod breaks off and bounces around while water is heated.
Replace anode rod when inspection shows exposed core is visible at top or bottom Water softener or acidic water <> inspect anode every 1-2 years
Hard water <> inspect anode 3-5 years
Tank with dual anode rod lasts longer. For example, 6-year tanks have one rod. All 12-year tanks have dual anode rods. Both rods are made of same metal to achieve longer life.
Read more > consider powered anode rod
Video of anode replacement
Home waterheatertimer.org
is a self-help site
Spring is stretched to length of tank during installation
Anode life: 100 yr for coated tanks
Visit seller's web site
Visit seller's pro water heater forum
Read about product
Read review of product and company
Anode rod depletion leads to rusted tank and possible water heater rupture ... the cost of water heater failure may not be fully covered by insurance .. home may be uninhabitable until water damage is repaired.
Intelligent anode rod warns homeowner before tank begins to rust
See insurance data on water heater failure (technical)
Hard-water WITH water-softener
Efficiency of gas and electric water heaters is unchanged over time when hard water
is softened, however soft water corrodes anode rod and will reduce life of
water heater unless anode rod inspected and replaced every 2 years.
Read more
Hard-water with NO water-softener:
> Gas: Efficiency of gas heater drops 6-8% after two years > cleaning tank of
sediment build-up will not restore full efficiency > however, regular
flushing to prevent sediment does maintain efficiency
> Gas: Tankless gas heater will fail when pressure sensor clogs with sediment
within 2-3 years depending on hardness of water > regular de-liming will not
restore efficiency > softener is required
> Electric: Efficiency of electric heater stays at 99% until sediment reaches bottom
element > cleaning tank restores full efficiency > regular flushing to
prevent sediment build-up also maintains efficiency
Water-softener reduces life of anode rod in gas and electric water heaters
Whirlpool water heater manual says: "Artificially softened water is exceedingly
corrosive because the process substitutes sodium ions for magnesium and calcium
ions. The use of water softener may decrease life of water heater tank."
Read pdf: water-softener/water-heater efficiency comparison
Electric storage-type water heaters operate at 99% efficiency
Gas storage-type water heaters operate at 69% efficiency
Tankless gas heaters operate at 80% efficiency
High-efficiency storage-type gas heaters up to 96% efficiency