Water heater repair or replace: how to decide

This is the most common question we get asked, and there is a reasonably clear framework for answering it. Three factors: age, what has failed, and what the repair costs relative to a replacement.

Start with age

A conventional tank water heater lasts eight to twelve years. In hard water without regular flushing - which describes a lot of Iowa - the lower end of that range is more realistic.

You can find the manufacture date in the serial number on the label. Most manufacturers encode the year and week in the first four characters, though the format varies by brand. If you cannot decipher it, we can.

Rough guide:

• Under 6 years: repair, nearly always. It should have plenty of life left.
• 6 to 10 years: depends on the failure and the repair cost.
• Over 10 years: lean toward replacement, especially for anything expensive.
• Over 12 years: replace. You are spending money on a tank that will fail anyway.

Then look at what failed

Almost always worth repairing

• Thermocouple (pilot will not stay lit) - inexpensive part, quick job
• Heating element (electric, no or little hot water) - inexpensive
• Thermostat - inexpensive
• Temperature and pressure relief valve - inexpensive and important
• Anode rod - moderate, and it extends tank life significantly
• Dip tube - moderate

Depends on age

• Gas control valve - a meaningful cost. Worth it under eight years, questionable past ten.
• Heavy sediment - a flush is cheap, but on an old tank the improvement can be limited.

Always replacement

• The tank itself is leaking. This is the one absolute. A tank leaks because the steel has corroded through from the inside. It cannot be welded, patched or sealed, and it will get worse. If water is coming from the body of the tank rather than a fitting, the heater is finished.

Worth distinguishing carefully: water at the base of a heater might be a dripping fitting, a weeping T&P valve, or condensation, all of which are fine. It is only terminal when it is the tank body itself.

The cost test

The rule of thumb we use: if the repair costs more than half the price of a replacement and the unit is past eight years old, replace it. Below that threshold, or on a younger tank, repair.

The reason is straightforward. Spending a meaningful sum on a ten year old tank often buys eighteen months, at which point you pay for the replacement anyway and have gained nothing.

Things that push toward replacing early

• It sits above a finished space. The consequences of a failure are much higher. Replacing on your schedule beats replacing at 6am with water in the ceiling below.
• It has never been flushed and it is over eight. Interior condition is likely poor.
• You have outgrown it. If you are already unhappy with capacity, a repair keeps you unhappy.
• Efficiency. A modern unit is meaningfully more efficient than one from the mid-2000s, which offsets part of the cost over its life.

Things that push toward repairing

• The unit is under eight and the failure is a common inexpensive part
• It has been flushed regularly and runs quietly
• You are selling within a year or two and a new heater will not return its cost
• Cash flow makes a replacement genuinely difficult right now - a repair buying twelve months is a legitimate choice, as long as you understand that is what you are buying

While you are deciding, consider tankless

If you are replacing anyway, it is the right moment to consider a tankless unit. It costs more up front, needs an adequately sized gas line, and wants descaling every year or two in hard water. In return you get hot water that does not run out and the floor space back.

It is not automatically the right answer. For a two-person household that never runs out of hot water, a good tank is better value. We will give you both prices and say what we think.

What we do

We diagnose first, then give you the repair number and the replacement number side by side, and let you choose. We are not going to condemn a serviceable heater, and we are not going to sell you a repair on a tank that is about to fail.