A solar water heater is one of the bigger home purchases you'll make for your bathroom, and it's a fixture you'll live with for a decade or more. So it pays to buy it right, not just buy it fast.
The good news is that the decision is simpler than the showroom makes it look. This buying guide takes you through it step by step: the type to choose, what a complete system should include, the right size for your household, whether your roof works, and who solar genuinely suits so you walk in knowing exactly what to ask for.
First, a quick refresher on how it all works, in the short video below.
How Solar Water Heaters Work
Source video: Sunbank Solar on YouTube
1How to choose a solar water heater: the 5 decisions
Quick Answer: Choosing a solar water heater means making five decisions in order: the collector type, what the system includes, the tank size for your household, whether it fits your roof, and whether your home suits solar at all. Get these right and the rest brand, model, finish falls into place.
In short, a roof collector heats your water using the sun, an insulated tank stores it, and a backup electric heater covers cloudy days. That's the whole system. The buying decision is about matching that system to your home, and it breaks into five clear steps:
- Decision 1 — Type: flat-plate, evacuated-tube or split.
- Decision 2 — What's included: the parts a complete system should have.
- Decision 3 — Size: the tank capacity for your household.
- Decision 4 — Roof fit: whether your roof has the sun and space.
- Decision 5 — Suitability: whether solar is the right call for your home.
We'll take them one at a time, then finish with a checklist you can take to the showroom. You can follow along against Big Bath's solar water heater range as you read.
2Decision 1: Which type should you buy?
Quick Answer: For most Malaysian homes, buy a flat-plate (thermosiphon) system — reliable, low-maintenance and well-suited to our sun. Choose evacuated tubes if your area is often cloudy, or a forced-circulation (split) system if you have a flat roof or want the tank kept indoors.
Your first decision is the collector type, because it shapes performance and how the system mounts. Here are your three options:
- Flat-plate, thermosiphon. A flat collector panel with the tank just above it; water circulates naturally with no pump; the default buy for most Malaysian homes.
- Evacuated tube. Vacuum-sealed glass tubes that lose less heat, so they hold up better on cloudy or hazy days.
- Forced circulation (split system). A pump moves water between the roof collector and an indoor tank, handy for flat roofs or when you'd rather not see the tank on the roof.
You'll also be asked to choose "pressurised" or "non-pressurised". Pressurised gives stronger flow at multiple outlets; non-pressurised is simpler. Big Bath carries both across its solar product range.
| Type | How it works | Buy it if... |
|---|---|---|
| Flat-plate (thermosiphon) | Flat panel + roof tank, natural flow | You have a sunny roof and want value |
| Evacuated tube | Vacuum glass tubes, less heat loss | Your area is often cloudy or hazy |
| Forced circulation (split) | Pump moves water; tank indoors | You have a flat roof or want the tank hidden |
Illustrative comparison; confirm the right system for your roof and climate.
Not sure which type fits your roof?
Compare systems side by side before you decide. Browse solar water heaters →
3Decision 2: What should the system include?
Quick Answer: Before you buy, confirm the package includes all the essentials: a roof collector, an insulated storage tank, a backup electric heater with a safety thermostat, and the mounting frame, pipes and valves. A quote that leaves parts out isn't a like-for-like comparison.
Solar is sold as a system, so the smart buyer checks what's actually in the box (and the quote). Use this as your inclusions checklist when comparing offers:
| Component | What it does / what to look for |
|---|---|
| Solar collector panel | Heats the water; a larger panel with copper riser tubes captures more |
| Insulated storage tank | Holds hot water; good insulation keeps it warm into the evening |
| Backup electric heater | Covers rainy days; insist on a resettable safety thermostat |
| Mounting frame | Secures everything to the roof; should suit your roof type |
| Pipes, valves & install | Connects the system; check if delivery and fitting are included |
Typical inclusions for a residential solar water heater; confirm exactly what each quote covers.
For reference, Big Bath's TORA system pairs a large 42-square-foot collector (with copper riser tubes) and an insulated tank with a backup electric heater and a resettable safety thermostat, and lists free delivery and installation so you can see what a fully-inclusive package looks like.
4Decision 3: What size should you buy?
Quick Answer: Buy the tank size to match your household. A 1–2 person home is usually fine with 40 gallons; a 3–4 person family suits 60 gallons; 5 or more people should buy 66 gallons or larger. Bigger tanks need a larger collector and more clear roof space.
Capacity is the number buyers most often get wrong. Buy too small and you run out during the evening rush; too big and you've paid for tank and roof space you don't use. Match it to the number of people in the home. Big Bath's solar range comes in 40G, 60G and 66G to cover most households.
| Household | Buy this tank | Roof / collector space |
|---|---|---|
| 1–2 people | ~40 gallons (150L) | Smaller; one collector panel |
| 3–4 people | ~60 gallons (225L) | Medium; larger collector |
| 5+ people | 66 gallons (250L) or larger | Larger, unshaded roof area |
General sizing guide based on typical Malaysian household use; confirm against your hot-water demand and roof.
5Decision 4: Will it fit your roof?
Quick Answer: Before buying, confirm you have a clear, unshaded patch of roof that gets good sun for most of the day. Pitched roofs are easiest; flat roofs need a tilted mounting frame; shaded or tight roofs may need a split system. Settle this before you pay a deposit.
The collector lives on the roof, so check your roof before you check out. The one non-negotiable is sunlight: the panel needs a spot facing the sun with little or no shade from trees, walls or taller buildings. Match your roof to the right setup:
- Pitched roof. The collector and tank mount directly on the slope, the simplest buy, and what most landed homes have.
- Flat roof / rooftop. Add a tilted mounting frame to angle the collector at the sun; common on bungalows and extensions.
- Tight or shaded roof. Look at a split system, which puts the collector where the sun is and the tank elsewhere.
- High-rise condo. Usually not possible for a single unit unless the building offers a shared system check with management before buying.
6Decision 5: Is solar the right buy for your home?
Quick Answer: Solar is the right buy for homeowners in landed houses with a sunny roof and steady hot-water use especially larger families. It's the wrong buy for renters, condo units without roof access, or very low hot-water homes, where a simpler electric heater is the better purchase.
Before you commit, sanity-check that solar genuinely suits your situation. It's a strong buy when you own a home with a good roof and use enough hot water to justify it. Find your row:
| Your situation | Should you buy? | Why |
|---|---|---|
| Landed home, sunny roof, big family | Strong yes | Roof space, sun and high hot-water use |
| Terrace or semi-D, 2–4 people | Yes | Most roofs work with the right mount |
| Shaded or very small roof | Maybe | A split system may still work |
| High-rise condo unit | Usually no | Usually no private roof access |
| Renting, or very low hot-water use | No | A fixed install or an instant heater fits better |
General suitability guide; your roof, ownership and hot-water habits decide the final call.
If solar isn't the right buy for you, an electric option may be — our guide on instant vs storage water heaters helps, and you can compare every option in the full water heater range.
7Your pre-purchase checklist
Quick Answer: Before you pay, run through five checks: the collector type for your climate, the tank size for your household, a built-in electric backup, the warranty length, and professional installation on a clear, sunny roof. Tick all five and you're ready to buy.
Take this to the showroom or run it past your supplier before you confirm the order:
- Collector type. Flat-plate for sunny areas; evacuated tube if your area sees a lot of cloud.
- Capacity. The tank matches your household using the sizing guide above.
- Backup heater. There's an electric backup with a safety thermostat for rainy days.
- Warranty. A long warranty on a rooftop fixture Big Bath's TORA carries 12 years on internal components.
- Installation and roof. Professional installation is included, and your roof has clear, unshaded, sun-facing space.
8The bottom line
Quick Answer: Buy by working through the five decisions — type, inclusions, size, roof fit and suitability then run the pre-purchase checklist. Do that and you'll buy a solar water heater that fits your home and keeps delivering hot water for years.
A confident purchase comes from a few clear decisions, not a leap of faith. Settle the type, the inclusions, the size and the roof, confirm solar suits your home, then you're ready to buy well. Still weighing it up? Our makeover consultants can walk the whole checklist with you and match the right system to your home.
Ready to buy the right solar water heater?
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9Frequently Asked Questions
1. How do I choose the right solar water heater?
Work through five decisions in order: the collector type for your climate, what the system includes, the tank size for your household, whether your roof has sun and space, and whether solar suits your home. Then run a final checklist covering the backup heater, warranty and professional installation before you buy.
2. What size solar water heater should I buy?
Buy by household. A 1–2 person home usually suits a 40-gallon tank, a 3–4 person family fits 60 gallons, and 5 or more people need 66 gallons or larger. Bigger tanks need a larger roof collector, so check you have clear, sunny roof space before buying.
3. What should be included when I buy a solar water heater?
A complete package includes a roof collector, an insulated storage tank, a backup electric heater with a safety thermostat, and the mounting frame, pipes and valves — ideally with delivery and installation. Compare quotes on inclusions so you're judging like for like, not just headline figures.
4. Does a solar water heater work on rainy or cloudy days?
Yes. A good solar system includes a backup electric element that switches on automatically when sunlight isn't enough, so you always have hot water. The insulated tank also keeps water warm into the evening, so a few cloudy hours rarely leave you cold.
5. Can I buy a solar water heater for a condo or rented home?
It's difficult. A solar water heater needs roof access and a fixed installation, so high-rise condo units usually can't have their own unless the building offers a shared system. Renters need the owner's approval. In both cases, an instant or storage electric heater is often the more practical buy.
6. How long does a solar water heater last?
A well-made solar system can last well over a decade, which is part of why it's worth buying carefully. Big Bath's TORA carries a 12-year warranty on internal components against manufacturer defects, a good indication of the expected lifespan when it's properly installed and maintained.
