When to Replace Your Water Heater (Not Just Repair It)
When to Replace Your Water Heater (Not Just Repair It)
Repair or replace? It's the question every homeowner faces when a water heater starts acting up. Here's the honest framework — including the Maryland well water factors most guides ignore.
How Long Should a Water Heater Last?
A standard tank water heater should last 10–15 years with proper maintenance. Tankless water heaters last 20+ years with annual descaling. But in Southern Maryland, untreated well water significantly shortens these lifespans:
High iron (above 1 ppm)
Iron deposits on the heating elements and inside the tank, reducing efficiency and causing early failure. We regularly see water heaters fail at 5–7 years in homes with untreated iron.
Low pH (acidic water)
Acidic water corrodes the tank lining and anode rod from the inside. The anode rod — which is designed to sacrifice itself to protect the tank — is consumed rapidly by acidic water, leaving the tank unprotected.
High hardness (above 10 GPG)
Scale deposits on the heating elements and at the bottom of the tank reduce efficiency and cause overheating. A water heater with significant scale buildup uses 20–30% more energy.
Signs It's Time to Replace (Not Repair)
The Maryland Well Water Rule: Treat the Water First
Replacing a water heater without addressing the water quality that destroyed the old one is a mistake we see regularly. The new unit will fail just as early as the old one — sometimes faster, because the scale and iron deposits from the old unit have already conditioned the pipes to deliver contaminated water.
Before replacing a water heater in a Southern Maryland well water home, we always test the water. If iron, hardness, or pH are outside the acceptable range, we recommend addressing the water quality as part of the replacement project.
- Iron above 0.3 ppm: install an iron filter upstream of the water heater
- Hardness above 7 GPG: install a water softener or TAC scale inhibitor
- pH below 7.0: install a calcite acid neutralizer
- All three: a whole-home treatment system in the correct sequence
Frequently Asked Questions
How long should a water heater last?
A standard tank water heater should last 10–15 years with proper maintenance. In Southern Maryland, untreated well water with high iron, hardness, or low pH can cut that to 5–8 years. Tankless water heaters last 20+ years with annual descaling.
Should I repair or replace my water heater?
If the water heater is under 8 years old and the repair cost is less than 50% of replacement cost, repair is usually the right choice. If it's over 10 years old, has a leaking tank, or has had multiple repairs, replacement is more cost-effective. Always address water quality issues alongside replacement.
How do I find the age of my water heater?
The age is encoded in the serial number on the label. The format varies by manufacturer, but typically the first two characters represent the year and month of manufacture. You can also look up the serial number on the manufacturer's website.