No hot water anywhere in the house
Every hot tap runs cold, even after waiting a few minutes.
Start here: Confirm whether the water heater is electric or gas, then check power or fuel supply first.
Water Heater Troubleshooting
John Wood Water Heater No Hot Water
Direct answer: If your John Wood water heater gives you no hot water at all, the first thing to sort out is whether you have an electric unit with no power or a gas unit that is not firing. Most no-hot-water calls end up being a tripped breaker, a reset button that popped, a pilot or ignition problem, or a failed heating element or thermostat on an electric tank.
Most likely: Start with the fuel type, then check the obvious supply issue before touching parts. On electric tanks, a tripped breaker or upper reset is common. On gas tanks, a pilot outage or ignition failure is more likely than a bad tank.
No hot water feels like a major failure, but a lot of the time the tank itself is fine. Reality check: one dead electric element can still give you some warm water, but no hot water at all usually points to lost power, a tripped safety, or a gas burner that never lights. Common wrong move: turning the thermostat way up before you know whether the heater is even running.
Don’t start with: Do not start by buying a gas valve, control board, or a whole new water heater just because the water is cold.
Electric or gas matters first.Find the rating label or look for a vent and gas line versus a power cable and breaker.
No hot water is different from not enough hot water.If every faucet stays cold after several minutes, follow this page. If water starts warm then fades fast, suspect a different issue.
Last reviewed: 2026-04-17
What no hot water looks like on a water heater
Electric water heater has gone completely cold
No burner sound, no recovery, and the tank does not seem to be heating at all.
Start here: Check the breaker, disconnect, and upper reset before assuming a bad element.
Gas water heater is cold and quiet
You do not hear burner ignition, and the pilot may be out or the status light may show a fault.
Start here: Look through the sight glass if present and verify whether the pilot or burner is actually lit.
Water heater was working, then stopped
Hot water was normal, then suddenly every shower and sink went cold.
Start here: Think supply interruption first: breaker trip, power loss, gas shutoff, pilot outage, or a reset that opened.
Most likely causes
1. Power loss to an electric water heater
A tripped breaker, disconnect issue, or loose supply leaves the tank completely cold with no recovery.
Quick check: At the panel, look for a tripped double-pole breaker and make sure any nearby disconnect is on.
2. Upper reset button tripped on an electric water heater
When the high-limit opens, the heater stops heating until the fault is corrected and the reset is pressed.
Quick check: Turn power off first, remove the upper access cover, and see whether the red reset button has popped.
3. Failed water heater heating element or thermostat
On electric tanks, a bad upper thermostat or upper element can leave you with little to no hot water at all.
Quick check: If power is present and the reset holds but the tank stays cold, the heating parts move to the top of the list.
4. Pilot, ignition, or burner problem on a gas water heater
If the pilot is out or the burner never lights, the tank will not heat no matter where the temperature setting is.
Quick check: Look for a live pilot flame or burner ignition through the viewing area and verify the gas shutoff is open.
Step-by-step fix
Step 1: Identify whether the heater is electric or gas, then check the basic supply
No-hot-water diagnosis goes in two very different directions. Sorting that out first saves time and keeps you from opening the wrong panels.
- Look for a metal vent pipe and gas line at the heater. If you see those, treat it as a gas water heater.
- If there is no vent and the unit is fed by a heavy electrical cable from a breaker, treat it as an electric water heater.
- For an electric water heater, check the home's electrical panel for a tripped double-pole breaker. Turn it fully off, then back on once.
- For a gas water heater, make sure the gas shutoff valve at the heater is parallel with the gas pipe, not crosswise.
- Check whether other gas appliances in the home are working if you suspect a gas supply issue.
Next move: If hot water returns after restoring power or fuel, keep using the heater but watch it closely over the next day. A repeat trip usually means an underlying fault. If supply is present and the heater still does nothing, move to the heater's own safety and heating checks.
What to conclude: This tells you whether the problem is outside the heater or inside it.
Stop if:
- You smell gas anywhere near the heater.
- The breaker trips again immediately after reset.
- You see burned wiring, melted insulation, or scorching around the heater connection.
Step 2: On gas units, check whether the pilot or burner is actually running
A gas water heater with no hot water is often just not lighting. That is more common than a failed tank.
- Set the thermostat to a normal hot setting, not maximum.
- Listen near the heater for ignition attempts or burner sound after hot water has been used.
- Look through the sight glass or burner view area if your heater has one. Check for a steady pilot flame or active burner flame.
- If the pilot is out and the lighting instructions are printed on the heater, follow only those printed instructions exactly.
- If the pilot lights but will not stay lit, or if the burner never comes on even with a live pilot, stop at diagnosis and arrange service.
Next move: If the pilot relights and the burner fires normally, give the tank recovery time and then test a faucet again. If there is no stable pilot, no ignition, or repeated shutdown, this is no longer a simple homeowner fix.
What to conclude: A gas heater that will not maintain flame points to ignition, combustion, or gas-control trouble, which is not a good guess-and-replace job.
Step 3: On electric units, check the high-limit reset before testing parts
The upper reset is a common no-hot-water stop point on electric tanks, and it is one of the few internal checks a careful homeowner can do safely with power off.
- Turn the water heater breaker fully off and verify no one turns it back on while you are working.
- Remove the upper access cover and insulation carefully.
- Press the red reset button once. It should feel firm; if it clicks, it had tripped.
- Reinstall the insulation and cover before restoring power.
- Turn the breaker back on and give the heater time to recover.
Next move: If the heater starts making hot water again, the reset had opened. That restores service, but it does not explain why it tripped. If the reset will not click, will not hold, or hot water still does not return after recovery time, the thermostat or heating element is more likely.
Step 4: If power is present on an electric unit, narrow it to thermostat or heating element failure
Once supply power is confirmed and the reset is not the whole story, the most likely repair parts are the upper thermostat or one of the water heater heating elements.
- Notice the pattern: absolutely no hot water often points to the upper thermostat or upper heating element on an electric tank.
- If you have some warm water but it runs out very quickly, the lower heating element is often the better suspect.
- Use a multimeter only if you know how to work safely with the power off and how to verify the circuit is dead before touching terminals.
- Inspect for obvious signs like a burned terminal, melted wire end, or mineral leakage around an element opening.
- If you do not test electrical components confidently, stop here and book service instead of guessing.
Next move: If testing confirms an open element or a thermostat that is not switching properly, replace only the failed water heater part with a correct match. If the readings are unclear or more than one control issue shows up, professional diagnosis is the safer move.
Step 5: Finish with the right next action instead of turning knobs and hoping
Once you know which path you are on, the fastest fix is a targeted repair or a clean service call with useful notes.
- If the breaker or reset tripped once and now the heater works, monitor it through a full day of normal use. If it trips again, schedule repair and mention the repeat trip.
- If an electric water heater test points to a failed thermostat or heating element, replace that confirmed water heater part and refill or re-energize the tank correctly before use.
- If a gas water heater will not keep a pilot or burner going, stop DIY and call for service. Describe whether the pilot is out, lights briefly, or never lights.
- If you find water leaking from the tank body, heavy rust at fittings, or active dripping onto electrical parts, shut the heater down and move straight to replacement planning or pro service.
- After any repair, run a hot faucet long enough to confirm steady hot water and normal recovery.
A good result: If hot water returns and stays consistent through several uses, the repair path was correct.
If not: If the heater still produces no hot water after the safe checks above, the remaining causes are not good guesswork jobs.
What to conclude: A clean diagnosis saves money here. Randomly replacing controls on a water heater is one of the easiest ways to waste time and still have cold water.
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FAQ
Why does my water heater have no hot water at all instead of just running out fast?
No hot water at all usually means the heater is not heating in the first place. On electric tanks that often means lost power, a tripped high-limit reset, or an upper thermostat or upper element problem. On gas tanks it usually means the pilot or burner is not staying lit.
Can I just press the reset button and be done?
You can press the reset on an electric water heater once after shutting power off and opening the upper access panel. If it restores hot water, that is useful information, but a reset that trips again points to an overheating or control problem that still needs repair.
If the breaker tripped once, should I keep resetting it?
No. One reset is reasonable for diagnosis. If the breaker trips again, stop there. Repeated trips can mean a shorted heating element, damaged wiring, or another electrical fault.
What part usually fails on an electric water heater with no hot water?
After power and reset checks, the most common repair parts are the upper thermostat and the heating elements. Which one is right depends on testing and on whether you have no hot water at all or only a short burst of warm water.
Should I replace the gas control valve if my gas water heater is cold?
Not as a first move. A cold gas water heater can be caused by a pilot outage, ignition problem, venting or combustion issue, or gas supply problem. Gas controls are not good guess-and-buy parts for homeowners.
How long should I wait after restoring power or relighting the heater?
Give the tank time to recover. A full tank water heater does not make hot water instantly. Small draws may warm up sooner, but a full recovery can take a while depending on tank size and fuel type.