What Size Water Heater Do I Need in Nigeria? | Volga

Water Heaters

Sep 12, 2026

The right water heater size depends less on how many people live in your home and more on how many people need hot water within the same busy period. For a storage water heater, start with your longest or most crowded run of showers, measure the flow, then check whether the model can deliver that amount before it needs time to reheat.

As a practical starting point, investigate about 45-50 litres for one regular shower at a time and around 80 litres for two regular showers taken back-to-back. Light handwashing or limited sink use may need only 5-15 litres. Long showers, high-flow showerheads, baths, several consecutive users or more than one outlet at once may require 100 litres or more, or a separately designed system.

These are comparison starting points, not universal prescriptions or statements of Volga model availability. Your actual requirement depends on flow rate, shower length, inlet-water temperature, heater setting, recovery time and the manufacturer's tested output.

Quick water heater size guide

Busiest hot-water use

Storage capacity to investigate first

What could change the answer

One hand basin or light, occasional sink use

5-15 litres

Sink size and how often hot water is drawn

One regular shower at a time

About 45-50 litres

Shower flow, duration, desired temperature and model performance

Two regular showers back-to-back

Around 80 litres

Long showers, a high-flow showerhead or another tap running

A bath, several consecutive showers or multiple outlets

100 litres or more, or project-specific sizing

Bath volume, simultaneous use, recovery time, plumbing layout and available power

Do not choose from this table alone. Use it to shortlist capacities, then ask the supplier or installer to confirm the model's usable hot-water delivery and recovery time for your routine.

Size the heater for your busiest period, not your household headcount

A family of four does not automatically need the same heater as every other family of four.

Suppose two adults shower before work while two children bathe later in the day. The heater mainly needs to cover the two morning showers. Another four-person household may take four showers one after another, which creates a much larger peak demand. A person who enjoys a long shower under a high -flow showerhead may also use more warm water than two people taking short showers.

This busiest period is often called peak-hour demand: the hot water used during the most demanding hour of a normal day. The related first-hour rating tells you how much hot water a storage heater can supply in an hour when it starts fully heated. Tank capacity contributes to that figure, but so do the heating element and the unit's recovery performance.

First-hour rating may not appear on every product listing in Nigeria. If it is unavailable, ask for the closest verified information: heating time from cold, recovery time after a draw, usable hot -water delivery and the test conditions behind those figures.

Measure one shower in five minutes

You can make a better estimate with a bucket, a measuring jug and a timer. Use cold or unheated water for the test.

  1. Set the shower to the flow you normally use.

  2. Collect the water for 15 seconds.

  3. Measure the number of litres collected and multiply it by four. That is the approximate flow in litres per minute.

  4. Multiply the flow by the usual shower length.

  5. Repeat for every shower or hot-water outlet used during the busiest period.

For example, a shower flowing at 6 litres per minute for 7 minutes uses about 42 litres of mixed warm water. Two such showers taken consecutively use about 84 litres.

That does not mean you automatically need an 84-litre tank. The shower mixes hot and cold water, while cold water enters the tank and the element may begin reheating. The correct comparison is between your estimated demand and the heater's verified usable output, not just the number printed on the tank.

For this example, an 80-litre class storage heater is a sensible place to begin comparing models. Move the shortlist up if the showers are longer, the flow is higher, another outlet runs at the same time or the heater cannot recover before the next user. A supplier or suitably qualified installer should confirm the final choice from the product data.

Check four specifications after choosing a capacity range

  1. Usable hot-water delivery: Nominal capacity is the amount the tank is designed to hold. It is not necessarily the exact amount of comfortable shower water you will receive. Tank design, thermostat setting, cold-water temperature, mixing and test method all affect usable delivery.

    Ask: "How many litres of mixed warm water can this model deliver under its stated test conditions?" A documented answer is more useful than a promise that a size is "good for a family".


  2. Heating and recovery time: Heating time describes how long the unit takes to bring its stored water to the stated temperature under stated conditions. Recovery describes how quickly it replaces the heat removed as water is used.

    These figures matter when people shower one after another. A smaller unit may be workable when users are separated by a reliable reheating period. The same unit may be frustrating when everyone must get ready within 30 minutes.


  3. Rated electrical input: Tank litres and electrical demand are different specifications. The rated input, shown in watts or kilowatts, determines the heater's immediate electrical load; tank volume influences how much water must be heated and often how long heating takes.

    If you plan to use grid electricity, a generator, an inverter or a solar -backed system, have a qualified professional compare the heater's nameplate rating with the supply, wiring, protection, battery capacity and other loads that may run at the same time. Do not assume a heater will work safely on backup power because its tank looks small.


  4. Installation requirements: Confirm the unit's dimensions, orientation, full installed weight, mounting surface, water -pressure range, plumbing arrangement and required safety components. Water weighs about one kilogram per litre, so the water alone in an 80-litre tank is roughly 80 kilograms before the appliance and fittings are added.

    A larger tank is not helpful if the wall cannot support it, the unit will not fit with safe access for servicing, or the electrical and plumbing systems are unsuitable.

Nigerian homes need a few extra checks

Work with the water pressure you actually have

Some homes receive water by gravity from an overhead tank; others use a pressure pump. The same showerhead can deliver different flow rates under different conditions. Measuring your real shower flow captures this difference better than guessing from the number of bathrooms.

If pressure changes when a pump switches on or when another tap opens, tell the installer. The heater must suit the plumbing arrangement and the pressure limits in its manual.

Plan around the available power window

Where grid supply is intermittent, households may heat water when electricity is available and use it later. In that situation, heat retention and enough stored usable water may matter more. If reliable power is available between showers, recovery may carry more weight.

Neither approach makes "bigger" automatically better. Compare the heater's documented heating time and heat-retention information with the hours when your preferred power source is available. Verify any efficiency or retention claim from current product documentation.

Treat borehole-water scale as a maintenance issue

If your water leaves visible scale on taps or showerheads, mention it when selecting a heater. Hard water can form scale when heated, but buying a larger tank is not a substitute for following the manufacturer's water-quality limits and service instructions.

Keep the electrical installation out of DIY territory

Water heaters combine electricity, heat, water and pressure. The Nigerian Electricity Supply and Installation Standards Regulations hosted by NERC specify an individual final circuit and an adequately rated doublepole switch for applicable single-phase domestic heaters, along with earthing and permanent -connection requirements. They also place bathroom switching outside the room in the circumstances described by the regulations.

Use a suitably qualified installer who follows the heater manufacturer's instructions and current Nigerian requirements. Do not improvise with a plug, extension lead, undersized cable or missing safety component.

Is a 30-litre water heater enough for a shower?

Do not treat 30 litres as a safe default for a normal shower. Published manufacturer guidance varies by product and market, but one established storage-heater guide places a regular shower in the 45-50-litre range and says its 30-litre units are not sufficient for a satisfactory shower.

A 30-litre model may still suit basins, a limited sink application or a very short, low-flow shower if themanufacturer's data and your measured demand support it. Check rather than assume.

What size water heater does a family of four need?

For a family of four, first count the showers taken during the busiest hour.

  • If only one person showers at a time and there is a reheating gap, begin by comparing models around the 45-50-litre range.

  • If two people take regular showers back-to-back, begin around 80 litres.

  • If all four shower consecutively, or a basin runs during the same period, compare larger capacities and recovery performance with a supplier or installer.

  • If the household mainly uses small buckets rather than showers, measure the actual litres used per person; the answer may be lower.

This method is more reliable than buying from family size alone.

Avoid these common sizing mistakes

  • Buying by bedrooms: bedrooms do not reveal shower length, simultaneous use or flow rate.

  • Treating tank litres as delivered shower litres: mixing and recovery change the usable amount.

  • Ignoring the second user: a heater that handles one shower may not handle two without a reheating gap.

  • Choosing the largest tank that fits: extra capacity can mean more stored water, more wall load and potentially more heat loss; it should serve a real need.

  • Judging backup-power compatibility by litres: the rated electrical input and required operating time.

  • Using an unverified online size chart as a guarantee: recommendations depend on product design and test conditions.

  • Forgetting future use: regular guests, a planned additional bathroom or a change from bucket baths to showers may justify more capacity.

Your final water heater sizing checklist

Before you choose a model, write down:

  • the number of showers or hot-water tasks in the busiest hour;

  • the measured flow and normal duration of each shower;

  • whether outlets run one after another or at the same time;

  • whether you can wait for the heater to recover;

  • the model's usable delivery, heating time and recovery time;

  • the rated input and the power source you intend to use;

  • the available wall space, mounting support and service access;

  • the home's water-pressure arrangement and any known water-quality issue; and

  • the installer's confirmation that the product and installation suit current requirements.

Volga supplies storage water heaters, not instant or tankless models. Once you have this use profile, compare Volga storage water heaters and ask the Volga Nigeria team to confirm current capacities, specifications and availability for your home or project. If you are unsure, contact Volga with the checklist above so the conversation starts with your actual needs.