The shower goes lukewarm halfway through. Or there is a rust-colored ring on the garage floor that wasn’t there last week. Either way, you are about to make a phone call, and the thing you want to know before you make it is whether this is a repair or a replacement.
The short version: if the tank itself is leaking, it is a replacement. Almost everything else is a repair, and the age of the unit decides whether the repair is worth making. The rest of this guide is how to tell which one you are looking at.
First, find out how old it is
Every water heater carries a rating plate, usually a sticker on the side of the tank near the top. The serial number on it encodes the month and year the unit was built. The format varies by brand, but the date is on there, and it is the most useful fact you can have before you call anyone.
Why it matters: a tank heater in this area typically runs eight to twelve years. That is the number we gave in our tank versus tankless guide, and it holds. A repair on a four-year-old unit is money well spent. The same repair on a thirteen-year-old unit is money spent on a tank that is already living on borrowed time, and you will often be back on the phone within the year.
The one symptom that is always a replacement
Water coming from the tank itself. Not from a fitting on top, not from the relief valve, not from a drain valve at the bottom that was never fully closed. From the steel.
A storage water heater is a glass-lined steel tank. Once the lining fails and the steel starts to rust through, there is no patch, no weld and no sealant that fixes it. The leak starts as a damp spot or a slow drip, and it only goes one direction. It doesn’t get better.
If you see water pooling under the unit, do three things: shut off the cold water supply valve on top of the heater, shut off the gas (or flip the breaker on an electric unit), and call. Those first two steps turn a flood into a puddle.
Symptoms that are usually a repair
No hot water at all. On a gas unit, this is often the pilot, the thermocouple or the gas control valve. On an electric unit, it is usually a heating element or a thermostat. All of those are parts.
Not enough hot water, or it runs out fast. On electric units, one of the two elements has usually failed and the other is doing all the work. Also a part.
Rumbling, popping or knocking from the tank. That sound is water trapped under a layer of sediment on the bottom of the tank, boiling and forcing its way up through it. Houston-area water carries plenty of mineral, and a tank that has never been flushed builds that layer faster than you would expect. Flushing clears it. If the noise has been there for years, the sediment may have already cooked the bottom of the tank, which is worth a look before you decide.
A drip from the relief valve. The temperature and pressure relief valve on the side or top of the tank is designed to open if the tank gets too hot or the pressure climbs too high. An occasional drip can mean it is doing its job because your house’s water pressure runs high. A constant drip usually means the valve itself has failed. Either way, a valve is a part. Don’t cap it or plug it. It is the safety device on a pressurized tank of hot water.
Rusty or discolored hot water, from the hot side only. This one sits on the fence. Often it is the sacrificial anode rod, a metal rod inside the tank that corrodes on purpose so the tank doesn’t. A fresh rod in a younger tank buys years. Rusty water from an older tank can mean the steel itself has started to go, and then you are back to the replacement column.
Where the line actually falls
Put the age next to the symptom:
- Under about eight years, and it is a part: repair it.
- Under about eight years, and the tank is leaking: replace it, and check whether the tank is still inside the manufacturer’s tank warranty. The date on the plate is what that claim rides on.
- Over about ten years, and it is a part: you can repair it, but ask for the replacement number in the same visit and compare. A sizable repair on a tank that could go any winter is not a good trade.
- Over about ten years, and the tank is leaking: replace it. There’s no other column.
That last case is the one that catches people, because it tends to arrive on the first cool morning of the year, when the incoming water finally drops and the heater has to work for the first time since spring. A tank that limped through a Houston summer gets found out in November.
One setting worth checking while you are down there
The thermostat. The U.S. Consumer Product Safety Commission urges households to set water heaters to 120 degrees Fahrenheit, and notes that most tap-water scald injuries are to the elderly and to children under five. A tank set hotter than that is also working harder than it needs to. It costs nothing to check.
What to have ready when you call
Three things make the call short:
- The date from the rating plate, or a photo of the plate.
- What you are seeing, as plainly as you can put it: no hot water, not enough, noise, a drip and where from, or water on the floor.
- Gas or electric, and roughly what size. The plate says this too.
With those, a plumber can usually tell you on the phone whether you are looking at a part or a tank.
How we handle it
We quote before we touch anything, and the quote is the number you pay. If it’s a part, we tell you it’s a part. If the tank is done, we say so, and we keep common models in stock for same-day swaps. Water heaters are our specialty, and our services page covers what that includes, from standard tank swaps to full tankless conversions.
If the water heater in your Magnolia, Pinehurst, Tomball, The Woodlands or Houston-area home is doing any of the above, call (281) 786-3695. Read the plate first if you can. It saves everybody a step.