Why Highland Lakes water heaters fail the way they do
Two things shorten water heater life around Marble Falls. The first is well water: untreated wells in the Hill Country run hard — calcium, magnesium, sometimes iron and fine sediment — with no treatment plant in between. That mineral load bakes into sediment at the tank bottom and scales heat exchangers, while the anode rod sacrifices itself at an accelerated pace. A tank that might last 12 years on soft city water can be struggling at 8 on a raw well.
The second is usage pattern. Vacation cabins and rentals swing between empty for weeks and packed with guests running every shower in the house. That thermal cycling — cold, hot, cold — stresses tanks more than steady daily use, and a unit sized for a couple suddenly faces six adults showering back-to-back. Add long vacancies where sediment settles undisturbed, and you get the Highland Lakes failure profile: scaled, anode-depleted, and undersized for peak weekends.
No hot water
Electric: failed element or thermostat. Gas/propane: thermocouple, gas valve, or pilot. Tankless: ignition, flow sensor, or scale-choked heat exchanger — very common on unmaintained well-water units.
Running out too fast
Sediment displacing capacity (well water accelerates this dramatically), a failed lower element, or a broken dip tube mixing cold water into the hot outlet.
Rusty or metallic water
Rust from hot taps only means the tank lining is failing — replacement territory. Orange or metallic tint from both taps on a well system may be iron in the supply, which is a filtration question.
Rumbling and popping
Sediment boiling — the signature sound of hard-water neglect. A flush helps early; years of baked-on scale may have already stressed the tank.
Water at the base
Rule out the TPR discharge pipe, drain valve, and condensation first. If the tank itself weeps, it can't be repaired — replacement is the only fix.
Rotten-egg smell
Classic well-water issue: sulfate-reducing bacteria reacting with the anode rod. Often fixed with a higher-temperature flush or an aluminum-zinc anode — not necessarily a new heater.
The anode rod matters more here
The anode rod — the sacrificial metal rod that corrodes so your tank doesn't — gets consumed faster in mineral-heavy well water, sometimes in as little as 2 to 3 years. Once it's gone, the tank itself starts rusting, and tank corrosion doesn't reverse. Checking the rod during a service visit takes minutes; replacing it costs a fraction of a new unit and can add years of life. If your heater is on well water and the rod has never been checked, that's the highest-value maintenance call you can make.
Well-water extras worth knowing
- Sediment filters. A whole-house sediment filter upstream of the heater keeps sand and grit out of the tank and valves. It's inexpensive and extends the life of everything downstream — not just the heater.
- Flush schedule. On a raw well, annual flushing isn't overkill — it's the baseline. We can show you how to do it yourself or handle it on a maintenance visit.
- That sulfur smell. Rotten-egg hot water on a well is usually bacteria reacting with a magnesium anode — not a dead heater. Treatment or an aluminum-zinc rod typically solves it.
- Pressure tanks and heaters. Well systems with failing pressure tanks send pressure spikes through the plumbing. If your TPR valve keeps weeping, the pressure tank may be the real culprit.
Our repair-vs-replace framework
- Under 8 years + failed component: repair it. Elements, thermostats, igniters, and gas valves are maintenance, not obituaries.
- 8–10 years + minor issue: repair if the tank is sound — no rust, no weeping — and check that anode while we're there.
- Over 10 years + significant failure: replacement usually wins, especially on well water where the tank has endured maximum mineral stress.
- Any age + leaking tank or rusty hot water: replace. The steel has failed; no part fixes that.
When replacement is the call, the deeper questions — tank vs. tankless for a rental, sizing for peak guest load, propane units, real costs — are covered in our Marble Falls repair vs. replacement guide.
What a repair visit includes
Diagnosis first: we test elements and thermostats, check gas or propane pressure and venting, inspect the TPR valve, trace any moisture to its source, and assess sediment load and anode condition. Then an exact upfront price — with repair and replacement options side by side when it's close, so you decide with real numbers. Most common repairs finish same-visit from truck stock.
