How to Choose a Booster Set? Selection Guide for Homes, Apartments and Industry (2026)

Weak water pressure on the upper floors, pressure dropping in the shower, or a pump that keeps switching on and off? Most of these complaints come from having no booster set at all, or from a booster pump sized wrongly for the building. This guide explains step by step how to choose a booster set, how to calculate flow and head, whether to choose a single or twin pump set, and which Pedrollo booster set suits which building.

Short answer: for a detached house or a single flat, a ready-to-use packaged booster set with a tank (e.g. Pedrollo Hydrofresh) is enough. Apartment buildings need a twin pump set (pumps alternate, and if one fails the other keeps supplying water), and buildings that need quiet operation and high pressure should use a booster set with vertical multistage pumps. Two values decide the right model: flow (m³/h) and head (m).

Quick Selection Table: Which Booster Set for Which Building?

What Is a Booster Set and How Does It Work?

A booster set (called a hidrofor in Turkey) is a water pressurisation system made up of a pump, a membrane pressure (expansion) tank, a pressure switch or electronic controller, and connection fittings. When a tap is opened, the line pressure drops, the controller detects it and starts the pump. When the tap is closed, the pressure rises to the set value and the pump stops. The tank prevents the pump from starting for every small draw-off, which saves energy and extends pump life.

Step 1: Determine the Flow You Need

Flow is how much water the booster set can deliver per hour (m³/h). In homes not every tap is open at the same time, so sizing is based on simultaneous use, not on the total number of taps. The values below are approximate figures for a first selection:

Step 2: Calculate the Head

Head shows how high, and at what pressure, the pump can deliver water (metres of water column; 10 m ≈ 1 bar). It is found with a simple calculation:

Required head = Building height + Pressure required at the highest tap + Pipe losses

• Building height: number of floors × about 3 m (add the basement if the pump is installed there).
• Pressure at the highest tap: usually 1.5 – 2 bar for comfort, i.e. 15 – 20 m.
• Pipe losses: depend on pipe length, elbows and valves; for small buildings add 5 – 10 m for a first estimate.

Example: in a 5-storey apartment block, building height is 5 × 3 = 15 m. With 20 m of pressure required on the top floor and 5 m of losses, the required head is about 40 m. The selected pump must deliver at least 40 m at the required flow, and this duty point should sit near the middle of the pump curve, not at its limits.

Step 3: Single Pump or Twin Pump?

• Single pump booster set: the economical choice for detached houses and small businesses. If the pump fails, the water supply stops.
• Twin pump booster set: the pumps run in turn (alternating) and wear evenly; under heavy demand both run together, and if one fails the other keeps supplying water. This is the type to choose for apartment buildings, residential complexes, hotels, hospitals and schools.

Step 4: Choose the Pump Type

Step 5: Choose the Right Tank Size

The tank reduces the number of pump starts. If the tank is too small, the pump cycles on and off too often, the motor overheats and its life is shortened. According to the Pedrollo catalogue, a 100 litre expansion tank is recommended for single pump MK-1H sets and 200 – 300 litres for twin pump MK-2H sets. Hydrofresh sets come ready to use with a 24 or 50 litre tank. To replace an existing tank, see our Nema membrane expansion tanks.

Pedrollo Booster Set Prices (November 2026)

At Isımatik, all Pedrollo booster sets and pumps are sold at list price excluding VAT; prices are shown on the site in Turkish lira at the daily exchange rate. Starting prices:

For all models and power options, see our Packaged Booster Sets category. Prices are list prices at the time of publication; the current price is shown on each product page.

5 Things to Watch During Installation and Use

1. Prevent dry running: on tank-fed booster sets, use a level float switch to protect the pump. See our float selection guide for details.
2. Check the tank pre-charge: the air pressure of the membrane tank should be about 0.2 – 0.3 bar below the pump's cut-in pressure. Check it at least once a year.
3. Install the suction line correctly: the suction pipe should not be narrower than the pump inlet, avoid unnecessary elbows, and fit a strainer at the start of the line. Otherwise cavitation will damage the pump.
4. Use a check valve and isolation valves: the check valve stops water flowing back when the pump stops; isolation valves let you separate the pump from the system for maintenance.
5. Choose the right power supply: models with an "m" (e.g. MKm, 2CPm) are single-phase 220 V; models without it are three-phase 380 V. Choose the model that matches your building's electrical supply.

Frequently Asked Questions

Why does my booster pump keep switching on and off?

The most common cause is a burst tank membrane or a low tank pre-charge. A leak in the plumbing or an undersized tank shows the same symptom. Check the tank air pressure first.

What pressure should a booster set deliver?

In homes, 1.5 – 2 bar at the highest tap gives comfortable use. The booster set's operating pressure is found by adding building height and pipe losses; use the head calculation above.

Should I buy a booster set or a pressure controller?

If you only want to run an existing pump automatically, a pressure controller is more economical. In systems with frequent small draw-offs, where the pump needs protecting, a booster set with a tank lasts longer.

Can an apartment building use a single pump booster set?

It can, but if the pump fails the whole building is left without water. That is why twin pump, alternating booster sets are recommended for apartment buildings and residential complexes.

Where are Pedrollo booster sets made?

Pedrollo has been manufacturing pumps in Italy since 1974. Pedrollo products sold at Isımatik are genuine and supplied with an invoice.