New fittings, disturbed sediment or corrosion may contribute to a metallic taste after a water-heater replacement, but taste cannot identify the cause or show that water is safe. Use cold water for drinking and cooking. Have the installer check the work and consider certified-lab testing, especially if cold water also tastes unusual.
Why would a new water heater make water taste metallic?
New copper or brass fittings can contribute, and a replacement may also disturb material in existing piping. The amount released depends on the materials and water chemistry, so new fittings do not establish the cause on their own.
Metal release depends on corrosion conditions and the water's chemistry. EPA's secondary-standard guidance identifies corrosion as a possible cause of metallic taste. That is a reason to investigate, not evidence that all new installations will cause a temporary taste.
### What the taste tells you
The EPA links a metallic taste to several metals. Its guidance on secondary drinking water standards lists a metallic taste for copper, iron, zinc and manganese, along with low pH. It also notes that corrosion of iron and copper can "impart objectionable metallic taste and red or blue-green color to the water supply."
These are taste and appearance standards. The EPA says it set them as "non-mandatory water quality standards" and that the contaminants "are not health threatening at the SMCL." A metallic taste is a signal to look closer. It doesn't by itself tell you the water is unsafe, and it doesn't tell you it's safe either.
So the color and staining can point to the source:
| What you notice | Likely metal (per EPA) |
|---|---|
| Metallic taste, blue-green stains | Copper |
| Metallic taste, rusty color or reddish stains | Iron |
| Bitter metallic taste, black or brown staining | Manganese |
| Metallic taste, no color | Copper or zinc |
Is it the hot water, the cold water, or both?
Note whether the reported change affects hot water, cold water, one outlet or several. Do not drink hot tap water to investigate. Tell the installer what you have already noticed and whether there is discoloration.
Cold-water piping normally bypasses the heater, so a change on the cold side broadens the investigation to shared fittings, the supply and possible mixing or cross-connections. It does not conclusively exclude the replacement work or a second cause. See why tap water tastes like metal for those causes.
A change limited to the hot side points the investigation toward the heater and hot-water piping, but inspection or testing is needed to identify the cause.
### Does it smell like rotten eggs instead?
That's a different problem. Rheem's manual says the heater's anode rod is "slowly consumed" to protect the glass-lined tank, and that water with high sulfate or mineral content, together with that process, "can produce a hydrogen sulfide, or rotten egg odor in the heated water." See whether a rotten egg smell in water is harmful. Rheem also says not to remove the anode rod except for inspection or replacement, since running without it "will greatly shorten the life of the glass lined tank and will exclude warranty coverage."
What should I do about it?
### 1. Drink and cook with cold water
This is good practice anyway, and it matters more with new plumbing. The EPA says to "Use only cold water for drinking, cooking and making baby formula."
### 2. Run the water after it sits
Metal builds up in water that sits in pipes. The EPA says "The more time water has been sitting in pipes, the more lead it may contain," and suggests flushing your pipes by running the tap, taking a shower, doing laundry or running the dishwasher. Follow the water supplier's flushing guidance for the property; a fixed flushing time does not establish safety for every plumbing layout.
### 3. Use your filter the right way
If you have a filter on the kitchen tap, it can help while the new fittings settle in. The EPA says to "make sure you use a filter certified to remove lead" and to replace the cartridge on schedule, since an expired cartridge is less effective. It also says, "Do not run hot water through the filter." A lead-removal certification does not establish removal of copper, iron or other possible causes; choose treatment based on test results.
### 4. Ask the installer to investigate
Report a new or worsening change rather than assuming it will fade. Ask which fittings were changed and whether the system was flushed according to the equipment and installation requirements. Testing can determine whether treatment or further repair is needed.
Was the new heater installed correctly?
A few installation details affect metal in the water.
Lead-free parts. Phoenix's adopted plumbing code, Section 605.2.1, says pipe, fittings, joints, valves and faucets used to supply water for drinking or cooking "shall comply with NSF 372 and shall have a weighted average lead content of 0.25 percent or less." The fittings used on a water heater install should be marked for drinking water use.
Dielectric protection. Where copper pipe meets the heater's steel fittings, dissimilar metals can corrode. A. O. Smith's manual says "To protect against untimely corrosion of hot and cold water fittings, it is strongly recommended that di-electric unions or couplings be installed on this water heater when connected to copper pipe." Our page on which connector a water heater should use covers the connection rules.
A full, purged tank. Rheem's fill steps say to open each hot water faucet slowly "to allow the air to vent from the water heater and piping," and that a steady flow from the hot faucet means the heater is full. For new piping, the code goes further. Section 610.1 says "New potable water systems shall be purged of deleterious matter and disinfected prior to utilization," and that the system is flushed "until dirty water does not appear at the points of outlet."
When should I test the water?
Taste alone can't tell you how much metal is in the water. Test it when:
- A new or persistent change has no confirmed explanation.
- You see blue-green stains, which point to copper.
- The household has a health concern requiring advice from the health department or a clinician.
- The cold water tastes metallic too.
EPA's Lead and Copper Rule uses a copper action level of 1.3 milligrams per liter in its public-system treatment requirements. That is not an individual household safety test. A certified lab can test for copper and lead together; ask the supplier or health department how to interpret the results. Cold-water and flushing guidance reduces some exposure risks but does not establish safety. If contamination is suspected, follow the water supplier or health department's advice about an appropriate drinking-water source while testing is arranged.
If the taste started with your new heater and won't go away, HQ can check the fittings, connectors and dielectric protection on the install. We're licensed and insured, and every estimate is free with upfront pricing.