Residential plumbing ยท Denver Metro, Colorado
Water heater maintenance and flushing
Flushing sediment out of the tank, checking the anode rod, testing the relief valve and checking the expansion tank help a water heater last longer and run quieter. On an older tank that has never been flushed, ask first, because opening the drain can start a leak.
Tank water heaters don't need much, but the little they need makes a real difference. Most problems we see on younger heaters trace back to sediment, a spent anode rod or pressure the system wasn't built to handle.
Flushing sediment
Minerals settle out of heated water and collect on the bottom of the tank. On gas heaters that's the popping or rumbling you hear: water trapped under the sediment boiling as the burner fires. On electric heaters, sediment can bury the lower element and burn it out. Flushing drains the tank under supply pressure until the water runs clear.
How often depends on your water and use. Many manufacturers suggest once a year; check your heater's manual.
The anode rod
Inside the tank is a metal rod designed to corrode instead of the tank lining. When it's used up, the tank starts to rust. Checking and replacing the anode on a heater that's a few years old is one of the few things that can actually extend tank life. A rotten-egg smell from hot water can also trace back to the anode reacting with the water; a different rod material often fixes it.
Relief valve and expansion tank
The temperature and pressure relief valve is a safety device; testing it briefly confirms it isn't stuck. In homes with a pressure-reducing valve or check valve, a thermal expansion tank absorbs the water's expansion as it heats. If its air charge is gone, pressure spikes every time the heater runs, which wears the tank and makes the relief valve drip.
Gas heater checks
On gas models, we look at the burner and flame, the vent connection and draft, and combustion air. A yellow, lazy flame or soot points to a combustion problem that should be corrected.
Tankless maintenance
Tankless units collect scale in the heat exchanger rather than sediment in a tank. They're descaled with a pump and solution through the isolation valves. See tankless repair and descaling.
A simple yearly routine
- Look around the base and fittings for damp or rust.
- Listen for popping or rumbling while it heats.
- Check that the relief valve discharge pipe is intact and points down to within a few inches of the floor or a drain.
- On gas models, look at the flame through the sight glass if there is one; it should be mostly blue.
- Flush per the manual, or have it done if the tank is older and has never been flushed.
- Every few years, have the anode rod checked.
Signs your water heater needs attention
- Popping or rumbling while the heater runs
- Hot water runs out sooner than it used to
- Sulfur smell from hot water only
- Relief valve drips
- The tank has never been flushed
- Rusty hot water
How a visit goes
- Check age and conditionOlder, never-flushed tanks get a careful look before we open the drain.
- Flush and inspectSediment out, anode checked.
- Test safety devicesRelief valve, expansion tank charge, gas draft.
- Report backWhat we found, what's fine, and anything to plan for.
What's different here
- Hardness varies. Front Range water ranges from soft to moderately hard depending on the source; Denver Water's reports, for example, describe its South Platte supply as harder than its Moffat supply. Check your provider's annual water quality report for the number.
- Closed systems. Many metro homes have pressure-reducing valves, which makes a working expansion tank important.
- Altitude. Burner and draft checks matter more at elevation.
What affects the cost
Every home is set up differently, so we price the job after we've seen it. These are the things that move the number.
- Tank ageOld tanks need more care when flushing.
- Anode replacementAccess and rod type.
- Expansion tankRecharge or replace.
- Relief valveReplace if it's stuck or leaking.
- Gas checksBurner cleaning or venting fixes if needed.
- AccessTight spaces take longer.
Questions we hear
How often should I flush my water heater?
Many manufacturers recommend about once a year; harder water or heavy use may call for more. Your manual has the specifics.
Can flushing an old water heater cause a leak?
Sometimes. Sediment can keep an old drain valve from resealing. On older tanks that have never been flushed, ask before doing it yourself.
What does the anode rod do?
It corrodes so the tank doesn't. Replacing it before it's used up can extend tank life.
Why does my hot water smell like rotten eggs?
Often a reaction between the anode rod and the water. A different anode material usually solves it. A gas smell is different: leave and call your gas utility.
Do I need an expansion tank?
If your home has a pressure-reducing valve or check valve, usually yes. It protects the heater and plumbing from pressure spikes.
Does maintenance void my warranty?
No; manufacturers generally call for it. Check your heater's manual for its schedule.
Can I maintain my water heater myself?
Many homeowners do the visual checks and a basic flush. Anode replacement, gas burner work and older never-flushed tanks are better left to a plumber.
Related services
Water Heater Repair & Replacement
Tank water heaters that leak, run out of hot water or won't light. Repaired when it makes sense, replaced when it doesn't.
Tankless Water Heaters
Wall-mounted tankless installs sized for Colorado winters, plus repair and descaling for the units you already have.
Water heater maintenance and flushing near you
We're based in Thornton and work across the Denver Metro:
Emergency plumber by city
Water leaking now? Shut off the main, then call.
Something leaking, dripping or cold?
Call and tell us what's going on, or pick a time online. If it's not something we handle, we'll say so.