Five signs your water heater is about to go

Most water heaters don't fail out of nowhere — they give you warnings for weeks or months first. Here are the five we see most in San Antonio homes, roughly in the order they tend to show up.

1. Rumbling or popping sounds

Sediment from our hard Bexar County water settles on the tank floor and traps steam bubbles underneath. That rumble you hear is water boiling its way through a layer of mineral scale — the tank working far harder than it should. It also means the bottom of your tank is being cooked every heating cycle.

2. Rusty or discolored hot water

Run the hot tap into a white bucket. If the water comes out rusty on the hot side only, the tank is usually corroding from the inside out. The anode rod — the sacrificial part that's supposed to corrode instead of the tank — is likely spent. Once the liner goes, replacement beats repair every time.

3. Water around the base

Even a small ring of moisture deserves a look. Sometimes it's a loose drain valve or a sweating fitting — cheap fixes. But a tank that has started to weep through a hairline crack will never leak less over time. It only picks the timing.

A 40-gallon tank flushed yearly can last 12+ years in San Antonio. Unflushed, expect 6–8.

4. Lukewarm showers that run out early

A failing heating element, a stuck dip tube, or a sediment blanket between the burner and the water all show up the same way: the hot runs out sooner than it used to. If your recovery time is getting noticeably longer, something inside is on its way out.

5. Age

Check the serial plate — most manufacturers encode the year in the first digits. Past year ten, you're on borrowed time, and it's worth budgeting for a replacement before the tank chooses its own moment (usually a holiday weekend, in our experience).

What to do about it

If your heater is showing two or more of these signs, have it inspected. A flush and an anode rod swap can buy years on a healthy tank — and if it's genuinely at the end, replacing on your schedule is always cheaper than replacing at midnight with a flooded garage.