How Long Does It Take to Fix a Hot Water Heater? Real Repair Times & What Delays It

You want a straight answer before the cold showers begin: how long will it take to get hot water back? Most fixes are under two hours once the tradie is on site, but a few jobs stretch longer because of draining, parts, or safety checks. In Wellington and across New Zealand, the big swing factor isn’t the wrench work-it’s diagnosis, access, and whether a part is on the van or needs a quick run to the supplier.

If you only need a ballpark for how long to fix water heater issues: small electrical or control faults often wrap in under an hour; parts swaps (like elements, thermostats, gas valves, tempering valves) usually take 45-120 minutes; messy leaks or full replacements run 3-8 hours. Below, I’ll break down real-world times by problem, what can speed things up, what slows them down, and how to plan your day so you’re not stuck waiting in a towel.

TL;DR: Repair times at a glance

• Quick wins (10-45 minutes): relight pilot, reset breaker/RCBO, clear error code, tighten a dripping joint, simple thermostat reset.
• Typical repairs (45-120 minutes): electric element or thermostat, tempering valve, anode, tankless igniter/flow sensor, descaling a gas califont.
• Longer jobs (1.5-3 hours): gas control valve, flue or condensate fixes, stubborn leaks, partial re-pipe, hard-to-access roof space work.
• Major work (3-8 hours): full cylinder replacement, relocation, seismic strapping upgrades, switch to continuous-flow gas (excludes consent steps).
• Heat recovery after the fix: tank systems need 30-180 minutes to reheat; tankless is instant once repaired.

New Zealand specifics that matter: gas work must be done by a licensed gasfitter (Plumbers, Gasfitters and Drainlayers Board). Electrical work on elements/thermostats should be done by a licensed electrician (Electrical Workers Registration Board). Building Code G12 and Building Act exemptions apply to some like-for-like replacements, but upgrades can need certification or consent. These rules can add time for booking, sign-off, and safety checks.

Diagnose the delay: problem-to-time map (electric, gas, tank, tankless)

Use this section like a decision map. Match your symptom to the likely fix and an honest time window. I’ll reference common NZ setups: mains-pressure cylinders (180-250 L), older low-pressure copper tanks, and continuous-flow gas units (Rinnai/Rheem are everywhere).

No hot water at all

• Electric cylinder - tripped breaker/RCBO or high-limit reset: 10-20 minutes to test and reset, plus 60-120 minutes for water to heat if the tank cooled fully.
• Electric cylinder - failed element or thermostat: 45-90 minutes if drain-down is minimal; 90-120 minutes if the tank must drain fully. Heating recovery: 60-150 minutes depending on element size (2-3 kW) and tank volume.
• Gas cylinder - pilot out: 10-30 minutes to relight and safety-check; if the thermocouple is shot add 30-60 minutes for swap (if on hand).
• Gas cylinder - gas valve/control issue: 90-180 minutes including pressure tests and leak checks; sometimes needs a return visit if parts aren’t in stock.
• Tankless (gas califont) - error code, no ignition: 30-90 minutes for diagnosis, sensor/igniter swaps, or intake/exhaust checks. Descaling adds 45-90 minutes.

Not enough hot water

• One element failed in a dual-element electric cylinder: 45-90 minutes for element/thermostat swap; reheat 60-150 minutes to full temp.
• Tempering valve stuck or mis-set: 30-60 minutes to test/replace and set to ~55°C outlet as per NZ scald safety norms.
• Heat pump water heater in cold weather: control setting change or defrost check 20-45 minutes; major component replacement can be 2-3 hours.
• Tankless undersized or flow-limited by a blocked filter: 20-45 minutes to clean filters and check gas supply; upsizing is a project (half-day+).

Leak or drip

• Drip at a compression fitting or union: 20-45 minutes to isolate, re-make, and test.
• Leaking tempering valve: 30-60 minutes to replace and commission.
• Leaking TPR (temperature and pressure relief) valve: 30-60 minutes to test and replace; add time if the drain line needs work.
• Tank body leak (cylinder itself): replacement job, 3-8 hours depending on access, seismic strapping, and pipe/flex connections.

Smelly water, popping noise, discoloured water

• Anode rod replacement (for glass-lined steel tanks): 60-120 minutes; longer if seized. This can cure odour from sulphur bacteria.
• Flushing sediment: 30-60 minutes, faster if there’s a full-bore drain cock. Popping sounds often settle after a good flush.

Flue, venting, and condensate (gas/tankless)

• Blocked flue/intake screen: 20-45 minutes.
• Condensate trap or drain blocked: 30-60 minutes to clear and test.
• Relocating or extending flue: 2-4 hours and may require extra materials and compliance checks.

Why draining can dominate the clock

Many electric element jobs are fast-if you don’t have to fully drain the cylinder. A typical 180 L tank drains at 8-12 L/min through a 10-15 mm drain cock on paper, but in real homes it often takes 30-60 minutes due to partial blockages, vacuum issues, or a buried drain hose. Opening a hot tap to break vacuum helps. If the element is high on the tank, a partial drain saves time.

Common Wellington-specific snags

• Older low-pressure copper cylinders: fragile joints slow the job; allow 30-60 minutes extra for care and re-making unions.
• Roof cavities and tight cupboards: access can add 30-90 minutes just for safe setup and spill control.
• Wind and flues: on the hill suburbs, downdrafts trip safeties; testing and fitting a cowl or baffle adds 45-120 minutes.

Who can legally do what (NZ)

• Gas work: licensed gasfitter required (Plumbers, Gasfitters and Drainlayers Board).
• Electrical work on elements/thermostats: licensed electrician (Electrical Workers Registration Board).
• Building/consent: Like-for-like water heater swaps can be exempt under Building Act Schedule 1 if done by licensed pros; changes in system type, location, or venting may need certification/consent per the NZ Building Code G12.

Plan the day: checklists, prep steps, and time-saving tips

Your time matters as much as the fix. Here’s how to help the job run to the short side of the estimate.

Quick decision tree

• No hot water and you have an electric cylinder? Check the switch and breaker/RCBO. If it re-trips, stop and call-likely a failed element or thermostat (45-120 minutes on site).
• Gas unit with no flame? Try a relight per the label. If it won’t hold, you’re looking at thermocouple or valve time (30-180 minutes depending on parts).
• Tankless with an error code? Note the code before you reset. A quick sensor swap or descaling is 45-90 minutes.
• Leak at the tempering valve or a union? Put a towel down, isolate if you can, and book it-most are 30-60 minutes.

How long will the tradie actually be at your place?

• Arrival window: 30-120 minutes is common. Peak winter and first cold snap days stretch this.
• Diagnosis: 10-30 minutes if symptoms are clear; longer if intermittent or hidden (roof space flues, buried leaks).
• Part run: add 20-60 minutes if it’s not on the van. Suppliers like Reece or Plumbing World are quick, but traffic and parking add noise.

Prep checklist to shave 15-45 minutes off the visit

• Clear access: 1 m around the cylinder or unit if possible. Move boxes, laundry, and anything that can get wet.
• Know the model: snap a photo of the data plate. For gas, include the error code.
• Water and power isolation: know where your mains water to the cylinder is, and the breaker or gas isolation point.
• Drain path ready: if there’s a chance of drain-down, have a hose and a safe drain point in mind (outside gully trap is common).
• Pets and kids: keep them clear; hot water work means hot pipes and tools.

What commonly delays repairs

• Seized fittings and elements: add 20-60 minutes. Old copper tanks are delicate.
• Stuck anode rods: can turn a 60-minute job into two hours if cut-outs or impact tools are needed.
• Hidden leaks: small drips show up only at pressure; finding them takes methodical testing.
• Compliance hurdles: gas pressure tests and leak checks are not optional; allow time.
• Cold ambient temps: heat pumps and adhesives cure slower in winter; factor extra time.

Cheat sheet: typical repair durations

Rules of thumb

• If draining is involved, add 30-60 minutes.
• If the flue or gas line is touched, add 30-45 minutes for safety tests and documentation.
• Every hard-to-reach cupboard or roof space adds 30-90 minutes.
• Winter callouts run longer than summer because everything takes longer when it’s cold and busy.

DIY vs pro: be honest about risk and time

• Safe DIY checks: power/breaker, thermostat setting on accessible covers, relighting a pilot per the appliance label, cleaning tankless inlet filters, flushing sediment via hose.
• Call a pro for: any gas work, wiring, elements/thermostats under covers, flues, and anything involving cutting or sweating copper. NZ law backs this up for safety.

FAQs and next steps: when to DIY, when to call, and how long until hot water returns

How fast will I have hot water after the fix?
Tankless: instantly. Gas cylinder: 30-60 minutes to feel it at taps. Electric cylinder: 60-150 minutes for a standard 180-250 L tank, slower if it started ice-cold or the element is smaller than 3 kW. Heat pump water heaters: 2-4 hours in cool weather.

Do all element jobs need a full drain?
No. If the element sits high on the tank, partial drain is enough. A full drain is needed when the element is low or when replacing a stuck anode. Partial drains cut 20-40 minutes.

Can I shower while the tradie works?
Usually not if they’ve isolated water or power. If the fix doesn’t need a drain-down (like a quick control swap), you might keep cold water. Ask before you plan around it.

Is a weekend or after-hours fix slower?
The on-site work isn’t slower, but parts runs can be. If it needs a specific valve or anode that isn’t on the van, you may get a temporary make-safe and a return visit on Monday.

What about consents in New Zealand-do they add time?
Like-for-like replacements by licensed people can be exempt under the Building Act’s Schedule 1. Upgrades (new gas installation, relocation, flue work, tempering valve changes) may need certification and sometimes consent. Gasfitting always needs a gas safety certificate. These steps add planning time more than wrench time.

How do I know if it’s a quick fix or a big job?
Three quick checks: 1) Is there an error code or tripped breaker? 2) Is the unit old (10+ years) or leaking from the tank body? 3) Is there a gas smell or soot around a flue? If it’s 1), likely quick. If it’s 2) or 3), plan for longer and don’t delay calling.

What brands matter for time?
Rheem and Rinnai are common here, and parts are usually easy. Obscure imports can add days if parts aren’t local. Your tech will tell you right away if something has to be ordered.

Is descaling a tankless worth the time?
Yes. In our water, scale builds up fast in continuous-flow units. A 45-90 minute descale often restores heat and flow and can stop ignition faults.

Why do tradies quote ranges instead of exact times?
Hidden surprises. A seized element, a fragile copper union, or a blocked drain valve can turn 45 minutes into 90. Quoting a range keeps it honest and avoids cutting corners.

How can I speed up the reheat after a repair?
For electric cylinders: switch to a higher element setting only if it’s within safe limits and per label, and avoid heavy hot water use until it’s back at temp. For gas, set to normal and wait 30-60 minutes before a long shower.

Is my system too small if hot water always runs out?
Maybe. A 180 L tank suits a small household; larger families often need 250 L or continuous-flow gas. Upsizing or switching is a half-day job plus any paperwork.

Next steps by scenario

• Electric, sudden no hot water: check breaker and the cylinder’s high-limit reset. If it trips again, stop. Book an electrician or hot water specialist; expect 45-120 minutes on site plus reheat time.
• Gas pilot out on a cold, windy night: try a relight following the sticker on the unit. If it won’t hold, you likely need a thermocouple (30-60 minutes) or valve (90-180 minutes). Keep windows open if there’s any odour.
• Tankless error after a big load (laundry + shower): note the code, clean the inlet filter, power-cycle. If it returns, book a pro-descaling and sensor checks take 45-90 minutes.
• Warm but not hot water at taps, suddenly: suspect the tempering valve. A swap and set-up is 30-60 minutes.
• Wet floor under the cylinder: isolate water if you can. If the body is leaking, plan for a replacement (3-8 hours) and protect the area from water damage.

Safety notes (because time isn’t worth a shortcut)

• Gas: only a licensed gasfitter should work on it. That’s not red tape; it’s life safety.
• Electric: power must be isolated and verified. Water and electricity don’t forgive mistakes.
• Hot surfaces: after repairs, pipes and valves can burn. Keep kids and pets away until it cools.

Realistic expectations if you’re booking today

• Same-day slot: mornings book out fast in winter. Afternoons are likelier for quick fixes.
• Parts: common parts (elements, thermostats, tempering valves) are usually in stock. Odd anodes or specific gas valves might be a next-day job.
• Communication: a good tradie gives you an arrival window, a first-hour diagnostic, and a clear go/no-go before opening more time.

Bottom line: most hot water problems are fixed in under two hours once someone qualified is in your cupboard. Things stretch when the tank has to drain, a part is seized, or a safety test flags another issue. Prep your space, note your model and symptoms, and you’ll stack the odds for a quick repair and a hot shower tonight.