Buying guide

How to Choose a Shower System

Shower systems are sold on the head and decided by the supply. A rain head that looks superb on a display board can be disappointing on a gravity-fed system and can overwhelm a drain when paired with a hand shower. Start from what the plumbing can deliver and remove, and the rest of the choice becomes straightforward.

The short answer

Quick Reference

Check supply pressure and flow before choosing any outlet.
A rain head needs volume; a low-pressure supply will disappoint with one.
Every simultaneous outlet adds to both supply demand and drain load.
Thermostatic valves prevent scalding when another outlet is used.
Concealed valves look better and must have planned service access.

A gold shower set mounted on a dark wall

Start here

Start at the Supply, Not the Head

A shower is a system with a fixed budget of water. The supply provides a certain pressure and flow, the valve controls it, the outlets consume it, and the drain removes it. Choosing outlets first and discovering the supply afterwards is how people end up with a rain head that produces a gentle drizzle.

Two numbers govern: the available pressure, and the available flow. High pressure with low flow behaves differently from low pressure with high flow, and a rain head needs volume rather than force, which is exactly the opposite of what people assume.

The drain is the fourth part of the system and the one most often forgotten. Everything that comes out has to go somewhere.

Supply pressure and flow set the budget
The valve controls and protects
Outlets consume, and they add up when used together
The drain must remove the total
A rain head needs volume, not pressure

Establish What the Supply Can Do

Single-hole, three-hole widespread and wall-mounted faucet types compared

Before anything else, establish the type of system and its performance. A mains-pressure system, an unvented cylinder, a gravity-fed tank system and a combination boiler all behave differently, and a fitting that performs beautifully on one can be poor on another.

Gravity-fed systems in older buildings are the common trap. They deliver low pressure, and many contemporary fittings, particularly rain heads with fine outlets, need more than that to perform. Fittings rated for low pressure exist and should be specified explicitly rather than hoped for.

The other direction matters too. Very high mains pressure without a regulator can be noisy and hard on cartridges, and some fittings state a maximum as well as a minimum working pressure.

Identify the system type before choosing fittings
Gravity-fed systems need fittings rated for low pressure
Rain heads need volume; fine outlets need more of it
Check both minimum and maximum working pressure
Where the supply is marginal, prefer fewer, larger outlets

Choosing the Outlet Combination

Each outlet is useful for something different, and the combination decides the total demand.

A rain head gives a soft enveloping spray and is what most people picture. It is also the least useful outlet for rinsing hair quickly or cleaning the shower, which is where a hand shower earns its place. A hand shower on a rail is the single most practical addition to any shower and is what makes the enclosure cleanable.

Body jets consume a great deal of water for a modest experiential gain and are the first thing to cut when the supply is marginal.

The important arithmetic is what happens when outlets run together. A rain head and a hand shower simultaneously can double the demand, and if the supply cannot deliver it, both perform poorly. If the drain cannot take it, the floor floods, which in a wet room with no upstand happens quickly.

Rain head for the experience; hand shower for practicality
A hand shower is what makes the enclosure cleanable
Body jets consume disproportionately; cut them first
Add up simultaneous demand, not individual figures
Confirm the supply can deliver the combined flow

Valve Type and Control

A wall-mounted faucet spout and handle shown separately

The valve is the safety component and the one that determines how the shower feels to use.

A thermostatic valve holds a set temperature regardless of pressure changes elsewhere in the building, which is what prevents the sudden scald when a toilet is flushed. A pressure-balanced valve maintains the hot to cold ratio and achieves much of the same protection more simply. For hotels, family bathrooms and any accessible installation, thermostatic control is worth specifying.

Where two outlets are fitted, a diverter directs flow between them. Confirm whether it allows both to run together or only one at a time, because that single detail changes the flow arithmetic above completely.

Concealed valves sit in the wall behind a plate and look considerably better. The cost is service access: the plate aperture is the only route to the cartridge, so confirm before specifying that the components likely to fail can actually be reached through it.

Thermostatic holds temperature through pressure changes
Pressure balanced maintains the hot-cold ratio more simply
Confirm whether the diverter allows simultaneous outlets
Concealed valves look better and constrain service access
Check what can be reached through the flush plate aperture

The Drain Has to Keep Up

A long linear floor drain in dark stone tiling

This is the step that gets skipped, and it produces a failure that is blamed on the enclosure or the waterproofing rather than on the specification.

Compare the total simultaneous outlet flow against the drain's rated capacity. A modest point drain sized for a single conventional shower can be overwhelmed by a rain head and hand shower running together, and in a wet room there is no tray upstand to buy time while the water clears.

Linear drains generally offer higher capacity for their footprint because the inlet is a long slot, which is one practical reason they suit high-output showers.

And confirm the floor falls toward the drain across the whole wet area, not just near it. No drain capacity compensates for a floor that sends water toward the door.

Compare total simultaneous flow against drain capacity
A rain head plus hand shower can overwhelm a small drain
Wet rooms have no upstand to buy time
Linear drains offer more capacity for their footprint
Confirm the fall runs away from the entry

Common questions

Shower System Questions

Why is my rain shower weak?

Usually because the supply cannot deliver the volume it needs. Rain heads require flow rather than pressure, and a gravity-fed system in an older building frequently cannot provide it. Fittings rated for low pressure should be specified explicitly.

Do I need a thermostatic valve?

It is worth specifying wherever a sudden temperature change would matter: hotels, family bathrooms and accessible installations. It holds a set temperature despite pressure changes elsewhere, which prevents the scald when another outlet is used.

Can a rain head and hand shower run at the same time?

It depends on the diverter. Some allow simultaneous operation and some do not, and the answer changes the flow arithmetic completely. Confirm it before sizing the supply and the drain.

Are body jets worth it?

They consume a great deal of water for a modest gain and are usually the first thing to remove when the supply is marginal. A hand shower adds more practical value for far less demand.

What drain do I need for a high-output shower?

One rated for the total simultaneous flow of the outlets specified, not for a single conventional shower. Linear drains generally offer more capacity for their footprint, which is why they suit rain head installations.

Are concealed shower valves harder to maintain?

Yes. The valve body is in the wall and the only access is through the plate aperture. Before specifying one, confirm that the components most likely to fail can actually be reached through it.

In short

The Supply and the Drain Bracket Everything

Establish what the supply can deliver, choose outlets that fit inside that budget, control them with a valve appropriate to who is using the shower, and confirm the drain can remove the total when everything runs at once.

A rain head plus a hand shower is the combination most people want and the one that most often exceeds both ends of the system. Check both before ordering rather than discovering it at first use.

Identify the supply type and its real pressure and flow
Rain heads need volume; specify low-pressure rated where needed
A hand shower is the most practical outlet in any shower
Thermostatic control where scalding matters
Size the drain for simultaneous flow, not a single outlet

Specifying showers for a project?

Talk to WNS Global

Tell us the supply type and the outlets you want and we will confirm the flow demand, recommend a valve arrangement, and check the drain capacity against the total so the shower performs rather than disappoints at handover.