How to Choose a Water Pump for Your House in Sri Lanka

Short answer: for a single-storey house with one or two bathrooms, a 0.5 HP pump is usually enough. For a two-storey house, or a house where a shower and a kitchen tap run at the same time, take 0.75 HP. Go to 1 HP when the tank sits high, the pipe run is long, or three or more outlets can be open at once.

The three things that decide the size

1. How high the water has to go. A ground-level pump feeding a roof tank on a two-storey house is lifting roughly seven to nine metres. Every extra metre of lift costs the pump pressure.
2. How many outlets can run at once. One bathroom is one thing; two bathrooms plus a kitchen plus a garden tap is another. Add up what realistically runs together on a weekday morning.
3. How long the pipe run is. A long horizontal run, and every elbow in it, eats pressure just as height does. Two houses with the same tank height can need different pumps.

The sizes we stock

All of these are in the Electricals section of the shop.

Do not buy bigger “just to be safe”

An oversized pump costs more to run, cycles on and off more often, and wears its pressure switch and seals faster. An undersized one never gets to rest, which is worse. The right answer is to match the size to the house, not to round up.

Fitting it right matters as much as the size

• Keep the suction side as short and straight as you can. Restricting the inlet is the most common installation mistake, and it makes any pump struggle.
• Fit a non-return valve on the suction line so the pump stays primed and the tank does not drain back when it stops.
• Use a flexible connector at the pump rather than hard pipe, so vibration does not crack the joint over time.
• Give the pump a dry, ventilated spot. A pump sitting in a wet pit fails on its electrics long before the mechanics wear out.

Signs your existing pump is the wrong size

• It runs continuously and never switches off — too small for the demand, or there is a leak in the line.
• It switches on and off every few seconds when a tap is barely open — usually the pressure switch or the tank, not the pump size.
• Pressure drops badly the moment a second tap opens — too small for the number of outlets.

Where to buy in Sri Lanka

WPL Trading in Warakapola stocks S-Lon and Solex pumps in all three sizes, along with the tanks, hoses, valves and fittings that go with them. Tell us your tank height and how many bathrooms the house has, and we will tell you which size fits.

Common questions

What HP water pump is best for a two-storey house in Sri Lanka?

0.75 HP is the usual choice for a two-storey house with two bathrooms and a roof tank. Move up to 1 HP if the tank sits higher than the roof slab, the run from pump to tank is long, or three or more outlets are used at the same time.

Can I use a 1 HP pump for a small house?

You can, but it is not better. A pump that is too large for the house switches on and off more often and costs more to run, without improving the pressure at the tap.

Why does my water pump keep running without stopping?

Either the pump is too small for the demand, or water is escaping somewhere — a running toilet cistern, a leaking joint, or a non-return valve that has failed and is letting the line drain back.

Does WPL Trading deliver water pumps?

Yes. Pumps go by courier anywhere in Sri Lanka, or you can collect from the shop at No. 305, Kandy Road, Dummaladeniya, Warakapola. Call +94 71 302 4843.

Need help choosing? Call +94 71 302 4843, message us on WhatsApp, or send your list through Request a Quote. WPL Trading, No. 305, Kandy Road, Dummaladeniya, Warakapola — open every day, 9.00 a.m. to 6.30 p.m., with island-wide delivery.

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