Small puddle only after heating
The floor gets wet after a heating cycle, but the tank body may look dry at first glance.
Start here: Check the temperature and pressure relief valve discharge pipe and the hot-side fittings before blaming the bottom.
Water heater leak troubleshooting
Ruud Water Heater Leaking From Bottom
Direct answer: If your Ruud water heater is leaking from the bottom, the water is often running down from somewhere higher first. The usual culprits are the drain valve, the temperature and pressure relief discharge, nearby fittings, or normal-looking condensation on some units. If the steel tank itself is leaking from the lower seam, the fix is replacement, not a part swap.
Most likely: Start by drying the heater and checking the drain valve and relief valve discharge path before you assume the tank is cracked.
Bottom leaks fool a lot of homeowners because water follows the jacket and piping before it drips onto the floor. Reality check: a puddle under the tank does not automatically mean the tank is bad. Common wrong move: tightening every fitting you can reach before you know which one is actually wet.
Don’t start with: Don’t start by buying a new water heater or replacing random valves while the jacket is still wet and the leak source is unclear.
Most common first checkDry the tank, valves, and pipes completely, then watch for the first fresh drip.
When to get serious fastIf water is coming from the tank seam, the burner area, or is spreading into walls or flooring, shut off the water supply and plan for repair or replacement now.
Last reviewed: 2026-04-17
What the leak looks like matters here
Steady drip at the front lower area
Water shows up near the plastic drain valve or lower front panel area.
Start here: Dry the drain valve and threads first, then watch for a fresh bead forming there.
Water around the whole base ring
The bottom edge looks wet all around and you cannot spot one obvious drip point.
Start here: Look higher for a fitting leak or relief discharge running down the jacket, then rule out condensation.
Rusty water or seepage from the tank seam
You see rust tracks, mineral crust, or seepage from the lower tank seam itself.
Start here: Treat that as a likely tank failure and move quickly to shut off water and arrange replacement.
Most likely causes
1. Water heater drain valve leaking
This is one of the most common true bottom leaks. The drip usually forms right at the drain outlet or around the valve threads at the lower front of the heater.
Quick check: Wipe the drain valve dry and wrap a paper towel around it. If the towel gets wet first, that is your leak source.
2. Temperature and pressure relief valve discharging water
A relief valve can drip into its discharge pipe, and that water often ends up at the base where it looks like a bottom leak.
Quick check: Feel and inspect the end of the discharge pipe after drying it. Fresh moisture there points to relief valve discharge, not a tank seam leak.
3. Leaking water line or top fitting running down the jacket
A slow leak at the hot outlet, cold inlet, or nearby union can track down the outside of the tank and collect at the bottom.
Quick check: Run your hand carefully around the top fittings and look for a wet trail or mineral streaks down the jacket.
4. Internal tank leak or lower seam failure
If the steel tank has failed, you may see rusty seepage, mineral buildup, or water appearing from under the jacket with no valve or fitting above it leaking.
Quick check: After drying everything you can reach, watch the lower seam and underside. If water returns there first, the tank is likely done.
Step-by-step fix
Step 1: Shut down the easy damage path and identify where the first drip starts
You need a clean starting point. On water heaters, the first fresh drip tells the story better than the puddle on the floor.
- If water is spreading, move stored items away and put down towels or a shallow pan to limit floor damage.
- If this is a gas water heater and you smell gas, stop immediately, leave the area, and call the gas utility or a qualified pro.
- Dry the floor, the lower jacket, the drain valve, the relief discharge pipe, and the visible piping with towels.
- Wait a few minutes and watch with a flashlight for the first new bead of water rather than the biggest wet area.
Next move: You spot the first fresh drip and can follow the leak source instead of guessing from the puddle. If everything stays dry until the heater runs, check again during or just after a heating cycle.
What to conclude: A leak that appears only during heating often points to relief discharge, expansion-related seepage, or condensation rather than a constant tank seam leak.
Stop if:
- You smell gas.
- Water is reaching electrical connections or controls.
- The leak is heavy enough that you cannot safely contain it while checking.
Step 2: Check the drain valve first
The drain valve sits low, so even a small seep there looks exactly like a bottom tank leak.
- Find the water heater drain valve near the bottom front of the tank.
- Dry the valve body, outlet, and the area where it threads into the heater.
- Place a dry paper towel under and around the valve, then watch for fresh moisture.
- If the valve handle is slightly open, close it gently by hand. Do not force it.
- If a hose cap or threaded cap is already installed and loose, snug it carefully by hand.
Next move: If the fresh drip starts at the drain valve and stops after it is fully closed or capped, you found the leak. If the drain valve stays dry, move up to the relief discharge and top fittings.
What to conclude: A wet drain valve usually means the valve itself is leaking or not fully seated. A dry valve pushes you toward another source.
Step 3: Rule out relief valve discharge and top fitting leaks
Water from above commonly runs down the jacket and fools people into thinking the bottom failed.
- Inspect the end of the temperature and pressure relief discharge pipe for drips or recent moisture.
- Check the area around the relief valve body if it is visible near the upper side of the tank.
- Look at the cold-water inlet, hot-water outlet, and any nearby unions or flex connectors for wetness, green corrosion, white mineral crust, or rust trails.
- Run a dry paper towel around each fitting and along the jacket below it to see where the water path starts.
Next move: If the discharge pipe or a top fitting gets wet first, the bottom puddle is just where the water ends up. If the top and relief path stay dry, keep going and check for condensation or a failed tank.
Step 4: Separate condensation from a real leak
Some water heaters sweat enough to make a small puddle, especially in humid spaces or when heating a cold tank full of incoming water.
- Look for fine moisture over a broad area instead of one clear drip point.
- Notice whether the leak shows up mainly when the heater has been working hard after a lot of hot water use.
- Check whether the water is clear and cool with no rust streaks or mineral trail leading to one fitting or valve.
- Wipe the jacket dry and watch whether it mists up evenly again rather than forming one bead at a valve, seam, or pipe.
Next move: If the moisture returns as light sweating over a wide area, you are likely dealing with condensation rather than a failed part. If one spot starts dripping again, that spot is the leak source and needs repair or replacement.
Step 5: Decide between a supported valve repair and tank replacement
Once you know the exact wet point, the next move gets much clearer and you avoid buying the wrong thing.
- If the drain valve is the only wet point and the tank body is dry, replace the water heater drain valve or have it replaced.
- If the relief valve or discharge path is the only wet point, the water heater temperature and pressure relief valve may need replacement, but repeated discharge also needs the underlying pressure or overheating cause checked.
- If water is seeping from the lower tank seam, from under the jacket, or from rusted steel itself, shut off the cold-water supply to the heater and plan for water heater replacement.
- For electric units, turn off power before any valve replacement work. For gas units, use a qualified pro if the repair puts you near gas controls, venting, or the burner area.
A good result: You end up with a clear next action: replace a confirmed leaking valve or replace the heater if the tank has failed.
If not: If you still cannot isolate the source, shut off the water supply to the heater and bring in a plumber before hidden damage gets worse.
What to conclude: A leaking service valve is repairable. A leaking steel tank is not a practical DIY repair.
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FAQ
Does a water heater leaking from the bottom always mean the tank is bad?
No. Bottom puddles often come from the drain valve, relief valve discharge, or a fitting above the tank. Dry everything first and look for the first fresh drip.
Can condensation make it look like my Ruud water heater is leaking?
Yes. In a humid space or after heavy hot water use, the jacket can sweat enough to make a small puddle. Condensation usually shows up as broad moisture, not one steady drip point.
Is it safe to keep using the water heater if it is leaking a little?
Only if you have confirmed it is a minor external seep and it is not reaching gas controls, venting, or electrical parts. A tank seam leak or active relief discharge is not something to ignore.
Should I replace the relief valve if water is coming out of the discharge pipe?
Maybe, but do not assume the valve is the only problem. Relief discharge can also mean excess pressure or overheating. If it keeps happening, have the cause checked.
Can I repair a leaking water heater tank with epoxy or sealant?
No. If the steel tank itself is leaking, patch products are temporary at best and usually fail quickly. The practical fix is water heater replacement.
What should I shut off first if the leak gets worse?
Shut off the cold-water supply to the water heater first. For electric units, turn off power. For gas units, use the proper shutdown setting and call a pro if the leak is near the burner or gas control.