Storage or instant geyser for a Nellore family? Size, wiring and water

For most Nellore families, a 15 or 25 litre storage geyser in the main bathroom is the right answer, with a 3 litre instant geyser worth considering for a second bathroom, a kitchen sink, or a single person who wants hot water without planning ahead. A gas geyser is a third option only for homes that can mount it outside the bathroom with real ventilation. The decision comes down to five things: how you bathe, how many of you, what wiring the bathroom already has, how often the power goes, and the fact that winter here is mild.

Bucket or shower decides the litres

A bucket bath uses roughly 15–20 litres of mixed water, of which perhaps half comes hot from the geyser. A shower of a few minutes uses more, and all of it passes through the geyser. So:

Household	Bucket baths	Showers
One or two people	6–10 L storage, or 3 L instant	15 L storage
Family of three or four	15 L storage	25 L storage
Larger family, one bathroom	25 L storage	25 L plus a second unit elsewhere
Kitchen sink, hand wash	1–3 L instant	—

Bigger is not free: a 25 L tank costs more to heat, loses more heat standing, and weighs close to 35 kg full, which matters on a hollow-brick bathroom wall.

Nellore's mild winter works in your favour

Inlet water in Nellore is rarely cold. Even in December and January it comes out of the tank on the roof at a temperature that needs only modest heating, and from March to September many homes do not use the geyser at all. Two consequences:

• You need fewer litres and less wattage than a buying guide written for Delhi suggests.
• An instant geyser performs better here than up north, because the small rise in temperature it has to deliver is within what a 3 kW unit can do at a usable flow.

Wiring: the deciding factor for instant

A storage geyser of 2 kW runs happily on an ordinary 16 A bathroom point with 2.5 sq mm wire. A 3 kW instant geyser is at the edge of that. A 4.5 kW instant geyser — the kind that gives a proper shower — needs 4 sq mm copper and a 20 A point, and evening voltage dips make it worse, because the same heater draws more current when the voltage sags. If the bathroom has an old light-and-fan wire to a single socket, an instant geyser means new wiring, and that belongs in the budget before the purchase. It is the reason most "new instant geyser keeps tripping the MCB" calls happen.

Power cuts

A storage geyser heated before a cut holds hot water for hours; an instant geyser gives nothing the moment the power goes. In a locality where evening cuts are routine, that is a real point for storage. Neither type should ever be run from an inverter — the load is far beyond a household unit.

Hard water and the coast

On borewell water, both types scale, but the instant geyser's tiny heating chamber scales faster and is less forgiving; it is the one to pair with an inline sediment filter. For storage, look for a glass-lined tank with a magnesium anode and plan an annual flush. On the coastal side — Muthukur, Krishnapatnam, the eastern edge of the city — pick a unit with a corrosion-resistant outer body and keep the terminal box dry.

Gas geysers, briefly

Fast, cheap to run, and unsuitable for a closed bathroom because of carbon monoxide. If you have a ventilated utility space outside the bathroom and the discipline to close the cylinder valve after every use, it can work. If not, this is not the option. We have a separate guide on gas geyser safety.

Features worth paying for, and not

Worth it: a BEE star label on a storage unit (insulation quality), a visible thermostat knob, a pressure-relief valve with a drain outlet, a glass-lined tank with a good anode, and a copper element if you are on hard water. Nice but optional: digital displays and app control, which add a board that is the expensive part to replace. Not worth it: capacity you will not use.

Installation and cost

Whatever you choose, installation is ₹699 — bracket mount, plumbing and electrical connection with an earth and RCCB check — and removing an old unit is ₹399. Extra wiring or plumbing runs are quoted separately before work starts. A geyser sized right and wired right is the one that never appears in the fault guides.