Plumbing Guides
What Size Water Heater Do You Need for Your Home?
A simple sizing guide for Nigerian homes — 10, 15, 30, 50 or 100 litres? How many people, bathrooms, bath tubs and your power supply decide the answer.
Quick answer
For one or two people, a 15–30 litre water heater usually works well; a family sharing one bathroom is safer with 50 litres; and filling a bath tub needs about 80–100 litres. A 10 litre heater suits one person or a small guest bathroom.
Key things to know
- Size the heater by how many people shower one after the other.
- A bath tub uses far more hot water than a shower.
- One heater per bathroom means less waiting and smaller heaters.
- Plan around your power supply — heat the water when power is available.
Buy a water heater that is too small and someone always ends up with a cold shower. Buy one that is too big and you pay more — upfront and in power — for hot water you never use. Here is a simple way to choose the right size for your home.
Quick sizing guide
| Who will use it | Suggested storage size |
|---|---|
| One person, or a small guest bathroom | 10 – 15 litres |
| A couple, one bathroom | 30 litres |
| A family of 3–4, or two bathrooms | 50 litres |
| A large family, a bath tub, or several bathrooms | 80 – 100 litres |
This is a starting point. The four questions below will help you fine-tune it.
Question 1: How many people shower one after the other?
A storage heater holds a fixed amount of hot water. If three people shower back-to-back in the morning, the tank must be big enough for all of them — or it needs time to heat up again between showers.
Question 2: Will you fill a bath tub?
A bath uses far more hot water than a shower. If you have a freestanding tub or a jacuzzi, choose a larger heater (often 80–100 litres) for that bathroom.
Question 3: One heater for the house, or one per bathroom?
In many Nigerian houses, each bathroom has its own heater. This keeps hot water close to the shower (less waiting and less wasted water) and lets you choose smaller heaters. A single large heater serving several bathrooms needs longer hot water pipes.
Question 4: What is your power situation?
Storage heaters heat the tank and then keep it warm thanks to insulation, so you can heat while power is available and use the water later. Instant heaters heat only while water is running but draw a lot of power at that moment — which matters if you rely on an inverter or a small generator. Read how to choose a water heater in Nigeria for more.
When in doubt between two sizes for a family bathroom, choose the bigger one. A slightly larger tank gives more comfort, and you can always set the thermostat lower.
When an instant heater makes sense
If one person uses a bathroom, or you need hot water at a single basin, an instant heater can be enough. It takes little space and only heats while water is running. But it draws a lot of power while running, so make sure your wiring and power supply can carry it.
Signs your heater is too small
- The last person in the morning always gets a cold shower.
- You have to wait a long time between showers for the water to heat again.
- You turn the thermostat to maximum just to get enough hot water.
If this sounds familiar, the next size up — or a separate heater for a second bathroom — will make a big difference.
Sizes we stock
- Ariston Andris RS — 15 L and 30 L
- Ariston Blu R — 10 L, 15 L and 30 L
- Ariston Pro1 R — 50 L and 100 L
- Maxilon Italy compact — 10 L, 15 L and 30 L
- Maxilon Italy instant — with digital display
Stock changes, so ask us what is available today. See storage water heaters and water heaters in Lagos.
Still not sure?
Send us three things on WhatsApp — how many people, how many bathrooms (and any bath tub), and whether you run on grid, generator, inverter or solar — and we will recommend the right size.
Get advice
Not sure what to buy? Ask us.
Send your photos, measurements or list on WhatsApp — or call — and we’ll recommend the right product with today’s price and delivery to your area.
Written by
Ecemeahara Global Ventures
A registered building materials dealer (OBMDA Reg. No. 1292) at Odun-Ade Building Materials Market, Badagry Expressway, Lagos. We write about the questions our customers ask us every day. About us · Our founder
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