Pump & Water System FAQs

Low water pressure in Irish homes usually comes from one of five things:

1. A gravity-fed system with too little height. Water flows down from the attic tank under its own weight, so showers on the top floor get very little pressure.
2. Weak or varying mains pressure in your area, often worse at busy times of day.
3. Narrow or long pipe runs that slow the water down.
4. A partly closed stopcock or valve.
5. Blocked shower heads or tap aerators, often from limescale.

The first one is by far the most common, and it's exactly what a booster pump solves. Use our low water pressure troubleshooter to pin down your cause.

Work through these steps in order. They take about 10 minutes.

1. Is it one tap or all of them? If it's just one tap or shower, the problem is at that outlet: a blocked aerator, a limescaled shower head or a faulty valve. A pump won't fix it.
2. Is it hot water, cold water, or both? Hot only usually points to the hot water cylinder or boiler. Both points to your supply.
3. Is it worse upstairs? That's the classic sign of a gravity-fed system without enough height. A booster pump is the fix.
4. Is your stopcock fully open? It's usually under the kitchen sink. Turn it fully anticlockwise.
5. Is your cold water tank filling properly? Look in the attic. If the tank is low or slow to refill, fix the supply first. A pump can raise pressure, but it can't create water.
6. Is it the whole area? Ask a neighbour. If they have the same problem, especially at certain times of day, contact Uisce Éireann.
7. Could there be a leak? If you have a water meter, turn every tap off and check whether it's still turning.

Still low, with the tank full? You need a booster pump. Call us on +353 1 456 4099 and we'll size one for your home, free of charge.

Yes, as long as you have enough water and it simply lacks pressure. A booster pump takes water from a storage tank and pushes it to your taps and showers at a strong, steady pressure. It can't create extra water, so the tank needs to refill properly. If your mains supply is too weak to keep a tank topped up, a PowerBox stores its own water reserve. If you're unsure, run through our troubleshooter first.

No. Water bylaws and Uisce Éireann's rules don't allow a pump to be connected directly to the public water main. It can pull water and pressure away from neighbouring homes and draw contaminated water back into the public supply. Every booster pump must be fed from a break tank: your attic tank or a dedicated tank at ground level. No tank? A PowerBox solves this: it combines a storage tank and booster pump in one unit that fills from the mains.

Yes. A PowerBox is built for exactly this. It's a complete package: a 300L or 500L tank, a submersible pump, controls and an acoustic pad, all pre-plumbed. It fills from your incoming mains, stores the water, and delivers it to every tap and shower at up to 3 bar and up to 100 l/min. That makes it the answer to low or unreliable mains pressure in homes and light commercial premises.

The pump sits underwater inside the tank, so it's quiet and never needs priming. It starts and stops on demand, with dry-run protection. There are three variants:

The 300L model is 630 mm in diameter and 1,170 mm high. The 500L model is 700 mm in diameter and 1,460 mm high.

For most homes, the Walrus HQ_B series is the answer. It's our flagship booster, in three sizes. Choose the EBARA Hydrostation where demand varies a lot through the day, or a PowerBox where you need stored water.

Tell us how many bathrooms and floors you have, and where your water comes from, and we'll recommend the right one, free.

The Walrus HQ_B performs exactly like the original Walrus HQ, with silver ions added to the casing. It puts the pump, motor, pressure tank and controller in one compact, quiet unit. It starts when a tap opens and stops when you're done. Its anti-cycling feature stops it restarting constantly because of a dripping tap or minor leak. It protects itself with a dry-run shut-off that resets automatically, plus motor overload protection. With a foot valve, it can lift water up to 7.6 m, so it can sit above the tank. It suits most homes, which is why it's our flagship booster.

The HQ series is our flagship booster pump range. The WQ series differs in two ways: it has a water-cooled motor, and its outlet can be taken from the top or the side. Otherwise the two are closely matched: the same tap ratings (up to 2, 3 or 4 taps), electronic control, dry-run protection and quiet running. Tell us about your home and we'll recommend the right model.

No. The booster pumps we stock are designed to run quietly, so they suit apartments, hot presses and homes where the pump sits near living space. The Walrus HQ_B has a low-noise design made for the home. The EBARA Hydrostation is near-silent at 43 dBA. The PowerBox pump sits underwater on an acoustic pad. Wherever the pump goes, fit stainless steel flexible couplings and a pump mat to reduce vibration travelling through the pipework.

For most homes, a fixed-speed pump like the Walrus HQ_B does the job well and keeps costs down. A variable speed pump, like the EBARA Hydrostation, ramps up and down with demand. That keeps pressure steady however many taps are open, and its IE5 motor matches energy use to demand. Choose variable speed for larger or high-use homes, or where demand varies a lot through the day. The Hydrostation also comes with a 3L pressure vessel and can be set up from your phone through the Hydrostation app.

Most booster pumps go beside or below the break tank, but they don't have to. The Walrus HQ_B can lift water up to 7.6 m with a foot valve, so it can sit above the tank. The EBARA Hydrostation is self-priming and handles a suction depth of up to 6 m. The PowerBox pump sits inside its own tank, so it never needs priming. Wherever it goes, keep the pump indoors and protected from frost, and fit flexible couplings and a pump mat to reduce noise.

The Walrus HQ_B and PowerBox both have dry-run protection. If the water supply runs out, the pump shuts itself off to avoid damage, and the Walrus resets automatically when water returns. If your pump keeps stopping, check that the break tank is refilling properly.

It depends on the pump:

• Walrus HQ_B: has a pressure tank built in, so most installations don't need a separate vessel. Where there are a lot of draw-offs or outlets, like a hair salon or a building with many wash hand basins, installers sometimes add one. If you do, match its air charge to the pump's own vessel, about 1 bar.
• EBARA Hydrostation: comes with a 3L pressure vessel to prevent frequent cycling.
• PowerBox: the Economy has its vessel in the controller. The Standard has one fitted externally. For the Variable, the vessel is supplied separately.

For other systems, a pressure vessel reduces how often the pump starts and extends its life. We'll tell you whether your setup needs one.

Yes. PowerBox pumps and controllers are sold separately, for replacement or for retrofitting an existing tank. Send us a photo of the rating plate on your current pump and we'll match the part.

Most apartment blocks, hotels, offices and schools need a twin-pump variable speed booster set, like the EBARA 2GPE Matrix. Two pumps share the load and back each other up, so the building is never left without water. The 2GPE handles up to 500 l/min and 72 m head. For light commercial and residential buildings, the single-pump EBARA 1GPE Matrix handles up to 250 l/min and 72 m head. We size every commercial set to the building, free of charge.

It depends on the number of flats and floors. This guide is for flats with two bathrooms and a kitchen, using the EBARA 2GPE Matrix:

The codes are 2GPE Matrix pump sizes. The guide assumes a new installation, with the set at ground level near the outlets. If the set will sit in a basement or garage, add one floor. Every building is different, so send us the details and we'll confirm the size.

Duty/standby means one pump (the duty pump) does the work, while a second pump stands ready to take over if the first stops. Duty/assist means that when demand rises beyond what one pump can deliver, the second pump joins in automatically. The EBARA 2GPE Matrix does both. Its pumps also alternate starts, so they wear evenly. That's why it's the standard choice for buildings that can't afford to lose water.

Both use EBARA's stainless steel Matrix multistage pumps with inverter control, holding a constant pressure however demand changes. The difference is how many pumps share the work:

• 1GPE Matrix: one pump, up to 250 l/min and 72 m head. It comes with a potable pressure vessel sized to the pump, and has dry-run, overload and voltage protection. Best for light commercial and residential buildings.
• 2GPE Matrix: two pumps on one base, each with its own inverter, up to 500 l/min and 72 m head. It has duty/assist and built-in standby, and comes factory assembled with manifolds, valves and two vessels. Best for apartment blocks, hotels, offices and schools.

Both run on a 230V single-phase supply as standard, with 400V three-phase drives available on request.

Yes. Every booster set is assembled, tested and commissioned by our team before it leaves us. It goes through factory hydraulic, mechanical and electrical tests, the pressure is set, and every function is checked. It arrives set up for your building, ready to connect, with the pressure vessels sized to the pump. On-site commissioning by our engineers is available on request.

A variable speed booster set runs only as hard as the building needs at any moment. Pressure stays steady whether one tap or fifty are open, running costs drop, and the pumps last longer because they aren't constantly switching on and off at full power. In buildings with uneven demand, like hotels at 7am, the energy saving is significant.

Under cover and protected from frost, at an ambient temperature between 0 and 40 °C. The water must be clean, with no solids or aggressive chemicals. The maximum working pressure is 10 bar. Set the vessel pre-charge to 20% below the running pressure. If the set sits in a basement or garage below the outlets, allow for the extra height when sizing it.

To size a commercial system properly, we need:

• The number of flats or units, and the number of floors.
• The number and type of outlets (showers, WCs, basins, kitchens).
• Where the set will sit: ground floor, basement or garage.
• The size and location of the break tank.
• The power supply available (single- or three-phase).

Drawings help if you have them. See Before you call us, or send us the details.

A submersible water pump works fully underwater, pushing water up to where it's needed rather than sucking it. That makes submersible pumps quiet and efficient, and able to lift water from great depths. There are three main types, and the right one depends on the job:

• Borehole and well pumps: long, slim pumps that sit deep in a borehole and supply a home, farm or irrigation system. See our borehole pumps.
• Drainage pumps: for clean, grey or lightly dirty water, like flooded cellars, sumps and rainwater. See our drainage pumps.
• Sewage pumps: built to handle solids, for wastewater and sewage. Also on our drainage and sewage page.

Not sure which you need? Call +353 1 456 4099 and we'll point you to the right one.

It depends on how deep the water is, how high it has to be lifted, and how much water you need. We stock three Stairs ST series of 4-inch stainless steel pumps:

Each series has several models, so the pump can be matched to the depth. For example, the ST-05 series runs from the ST-0510 to the ST-0526. Units of 2, 3 and 5.5 HP are available on request. Tell us the well depth and what it's supplying, and we'll match the pump, motor and control box, free.

Our 4-inch pumps and motors are built for boreholes of 4 inches and larger. Your well driller's report should show the casing size. If you don't have it, measure the inside diameter of the casing at the top of the borehole, or call us and we'll help you work it out.

A borehole set has three essential parts, plus an optional pressure system. We supply them together, matched and ready to install:

1. A 4-inch Stairs ST pump. It's stainless steel, with a built-in non-return valve that keeps the rising main full.
2. A matched 4-inch motor. It's stainless steel and factory tested. Single-phase 230V is standard, and three-phase versions are available.
3. A control box. Every single-phase motor runs through a control box matched to its size, containing the run capacitor, overload protection and an on/off switch.
4. Submersible cable. Four-core cable, cut to the length of your borehole and sized to the motor (4 × 1.5, 2.5 or 4 mm²).
5. A pressure system (optional). A pressure vessel, pressure switch, gauge, brass 5-way connector and 1-inch lever valve, supplied together. A 60L vessel is standard, horizontal or vertical, and other sizes are available.

The pump lifts water from the borehole into a pressure vessel, and a pressure switch turns the pump on and off. When you open a tap, water comes from the vessel first. When the pressure drops to the cut-in point, the switch starts the pump. When it reaches the cut-out point, the pump stops. Our pressure switch is factory set at 1.4–2.8 bar and can be adjusted on site between 1.4 and 4.6 bar.

In almost every case, yes. Without one, the pump would start every time someone opened a tap, even for a glass of water. Our Stairs motors are rated for a maximum of 40 starts an hour, so constant starting shortens their life. A correctly sized vessel gives you steady pressure and fewer, longer pump runs. Our borehole pressure system comes with a 60L vessel as standard, horizontal or vertical, and we supply drinking-water vessels from 2L to 1000L.

Rapid on-off switching (called "short cycling") is usually caused by the pressure vessel. Either it has lost its air pre-charge or its membrane has failed. Check the pre-charge first (see How do I check a pressure vessel's pre-charge?). Other causes include a leak in the system or a faulty pressure switch. Fix it quickly, because short cycling wears out the pump and motor.

Fit a filter housing on the supply into the house to catch sand, grit and rust before they reach taps, appliances, impellers and valves. For wells and boreholes, use a 10" Jumbo housing, or a 20" Jumbo for heavy sediment, with a cotton cartridge for sand, grit and rust or a PP cartridge for finer particles. If the water is still cloudy after filtering, get it tested. See our water treatment range.

Choose by what's in the water. Every pump we stock is stainless steel and fully submersible:

Never use a drainage pump for sewage. It will clog and fail. Tell us what you're pumping and how high it has to go, and we'll match the pump to the job.

For a flooded cellar, basement or small sump, a compact 0.25 kW pump like the EBARA Optima or EBARA Best One is the usual choice. They handle clean and grey water with solids up to 10 mm, at up to 150–170 l/min. The outlet is on top, so they stay slim enough for small manholes. Choose a float version and the pump runs automatically. For bigger volumes, the EBARA BEST 2–5 moves up to 360 l/min. Flooded right now? You can collect the same day from our Ballymount premises in Dublin 12. Call +353 1 456 4099 first to check stock.

In a vortex pump, the impeller sits recessed above the pump inlet. That makes it better equipped to handle solids than a standard drainage impeller. Our vortex range includes:

• EBARA Best One VOX: solids up to 20 mm.
• EBARA RIGHT and Stairs XV-07: solids up to 35 mm.
• Stairs XV-10 / XV-15 and EBARA DW VOX: solids up to 50 mm.

The standard EBARA DW uses a single-channel impeller instead, which gives more head and flow, up to 900 l/min and 21.8 m on the DW 300.

Yes. Many of our pumps come with a float switch as standard, so they start as the water rises and stop when it drops. Single-phase versions of the EBARA BEST 2–5, RIGHT and DW, and the Stairs XD and XV, are supplied with a float switch. The Optima, Best One and X1-03 come in cable, vertical or ball float versions, with the same performance as the non-float models. Use a vertical float in a tight sump, and a cable float where there's room for it to swing. Three-phase pumps need a separate float switch and a motor starter with overload protection.

The EBARA BEST 2–5 is built for it. It's all stainless steel, inside and out, with two mechanical seals instead of one. It moves up to 360 l/min, with up to 19 m of head, and can be submerged up to 7 m deep. A built-in strainer keeps out debris over 10 mm. You can fix it in a sump or carry it to wherever the water is. It runs on a single-phase supply with a float switch, or on three-phase.

It depends on the problem. Well, borehole and mains water can each carry different things, and each needs a different treatment:

If you're combining treatments, fit them in this order: sediment, then carbon, then UV. Filtering first stops particles shading microorganisms from the UV light. If you don't know what's in your water, get it tested first so you treat the right problem.

A UV steriliser treats microorganisms in your water using ultraviolet light, without adding any chemicals, taste or smell. As water flows past the UV lamp, the 254 nm light damages the DNA of microorganisms, including Giardia and Cryptosporidium. It's most often fitted on private wells and boreholes. Our UV sterilisers handle flows from 7.6 to 91 l/min. For it to work:

• Fit it last, after the sediment and carbon filters.
• Size it to your peak flow, not the average flow.
• Keep it switched on.
• Leave room at one end to slide the lamp out for changing and cleaning.

If a test finds bacteria in your well water, follow your local authority's advice before drinking it.

A reverse osmosis (RO) system pushes water through an extremely fine membrane that reduces dissolved solids and heavy metals, giving you clean drinking water at a dedicated tap. We stock two:

• Compact RO (1200 GPD): high-flow drinking water. It makes about 4,540 litres a day at 3.12 l/min and fills a glass in about five seconds. It's just 150 mm wide and uses two stages, with twist-and-pull filters you change by hand. It needs a socket and a drain connection under the sink.
• 5-stage RO with booster pump: five filters in series plus a 3-gallon storage tank. Its built-in booster pump keeps the membrane working on low mains pressure, and it uses standard 10" cartridges. It's designed for mains water. On a well or borehole, treat the supply first.

A 20-inch housing takes a cartridge twice the length of a 10-inch one, so it holds more dirt and needs changing less often. Jumbo housings take a wider cartridge for even more capacity.

Every housing takes cotton (sand, grit and rust), PP (fine particles) and block carbon (chlorine, taste and odour) cartridges. A clear bowl lets you see when the cartridge needs changing.

It depends on your water quality and how much you use. As a typical guide, based on our 5-stage RO system:

• Sediment cartridges: every 4–6 months.
• Carbon cartridges: every 6–12 months.
• RO membranes: every 12–24 months.

Sediment cartridges block faster where there's a lot of sediment, and a drop in pressure or a dirty clear bowl tells you one is due. The Compact RO has a filter-life reminder. Before opening a filter bowl, always press the relief button to release the pressure. When refitting, seal threads with PTFE tape only, never paste or hemp.

Get it tested by an accredited laboratory. We don't test water ourselves, but your local authority can point you to testing options. If you have a private well, the EPA advises testing it at least once a year. Once you have the results, send them to us and we'll put together the right treatment.

FRP (fibreglass reinforced plastic) tanks hold the treatment media in water softeners and whole-house filters. Fill one with the media that suits your problem:

• Softener resin: removes hardness, so there's less scale in kettles, boilers and pipes.
• Activated carbon: reduces chlorine, taste and odour across the whole supply.
• Sand or multimedia: traps sediment and cloudiness at higher flows than a cartridge.

They won't rust, and they're light enough for one person to position. They're rated to 10 bar and take the standard 2.5-inch top-mounted control valves. Sizes are 39, 50 and 104 litres. Tanks are supplied empty, with the base fitted. The media, control valve and internals are sold separately. Send us your flow and a water test result and we'll size it.

A pressure vessel stores water under pressure in your system. When you open a tap, small draws come from the vessel instead of the pump, so the pump starts less often and runs for longer when it does. That means steadier pressure and a longer pump life. In our drinking-water vessels, the water sits inside a potable-grade membrane and never touches the steel.

It depends on the job:

Tell us the pump and the pressure you need, and we'll size the vessel and set it up. See all pressure vessels.

A pressure vessel stores water under pressure so the pump starts less often. An expansion vessel sits on a closed heating circuit and takes up the extra volume as the water heats, so the pressure stays in range and the relief valve stays shut. Don't swap one for the other. Our MaxiVarem LR heating expansion vessels are for closed heating circuits only, not drinking water. For drinking water, use a potable vessel such as the Varem ExtraVarem, where the water sits inside a potable-grade membrane and never touches the steel.

Fit it close to the pump outlet, ideally on a brass 5-way connector, which joins the pump, vessel, pressure switch, gauge and outlet in one fitting. Add an isolating valve so the vessel can be serviced without draining the system. Our horizontal vessels (36–100L) have a pump stand built in, so the pump sits on top of the vessel.

A pressure vessel needs the right air pressure (pre-charge) to work. Check it once a year:

1. Switch off the pump at the electrics.
2. Open a tap until the water stops flowing and the water side has no pressure.
3. Check the air valve on the vessel with a tyre pressure gauge.
4. Compare the reading with the correct setting:
   • Fixed-speed pumps: 0.2 bar below the pump's cut-in pressure.
   • Extra vessel added to a Walrus HQ_B: match the air charge in the pump's built-in vessel, about 1 bar.
   • Variable speed pumps: 20% below the running pressure.
   • PowerBox: 1.5–1.8 bar.
5. Top up with a tyre pump if it's low.

If water comes out of the air valve, the membrane has failed and the vessel needs a new membrane or replacing.

Flexible couplings reduce pump vibration travelling down the pipework, so installations are quieter, and they protect joints from stress. Ours have a corrugated HDPE core that bends tight without kinking, an AISI 304 stainless braid and brass ends. They're drinking-water approved, fitted by hand without tools, rated to 10 bar, and come in sizes from ½" to 2". See flexible couplings.

We stock everything that goes after the pump:

• Pressure switch: starts and stops the pump. Factory set at 1.4–2.8 bar, adjustable from 1.4 to 4.6 bar.
• Float switch: switches a pump on water level, to fill a tank or empty a sump. Single or dual function.
• Pressure gauge: shows system pressure at a glance, in 0–6 or 0–10 bar.
• Brass 5-way connector: one fitting that joins the pump, vessel, pressure switch, gauge and outlet.
• Brass fittings: EN 1982 brass, drinking-water safe, ½" to 2".
• Polypropylene fittings: blue-pipe compression (19 mm × ½" to 63 mm × 2") and threaded (½" to 2").

See all accessories.

A pressure switch starts the pump when pressure drops to the cut-in point and stops it at the cut-out point. Ours is factory set at 1.4–2.8 bar, and both points can be adjusted on site between 1.4 and 4.6 bar. Always isolate the power before you open the cover. Fit a pressure gauge so you can watch cut-in and cut-out while you set it. If you change the cut-in pressure, reset the vessel's pre-charge to 0.2 bar below it: see how to check a pressure vessel's pre-charge.

Contact us for a quote by phone on +353 1 456 4099, by email at info@njpower.ie, or through our quote form. We accept credit card, payment link and bank transfer.

Yes. Most of our customers are plumbers, contractors, engineers and mechanical and electrical firms, and we offer trade accounts for them. Contact us to set one up.

Order in-stock items before 12pm, Monday to Friday, and we'll deliver the next working day anywhere in the Republic of Ireland, to site or door. We also deliver to Northern Ireland.

Yes. Call in to our trade counter at U7 Ballymount Business Park, Dublin 12 (D12 H3CX). Orders are often ready the same day. Our opening hours are:

• Monday to Thursday, 8:30–17:00
• Friday, 8:30–16:30
• Closed for lunch 13:00–14:00, and at weekends

Call ahead to make sure your order is ready.

Every product we supply comes with a 2-year warranty as standard, excluding consumables such as filter cartridges, UV lamps and RO membranes. As an authorised distributor, we sell genuine products backed by the manufacturer.

Yes. Pump sizing and technical advice are always free, whether you're a homeowner with low water pressure or a contractor specifying a commercial booster set. Call +353 1 456 4099.

Datasheets, brochures, manuals and performance curves for the products we stock are on our datasheets page and on each product page. Can't find the one you need? Ask us and we'll send it over.

Pond, fountain and water feature equipment is handled by our sister company, Aqua Decor (opens in a new tab), an OASE Gold Certified Partner. They stock OASE pond pumps, filters, lighting and fountain sets.

We install domestic booster pumps and commercial booster sets across Dublin city and county. Borehole pumps, drainage and sewage pumps, and water treatment systems are supplied for your installer to fit. We match every part to the job, and we're happy to talk your plumber or installer through the setup. Outside Dublin, we deliver nationwide (next working day on in-stock items).

Yes, for the brands we sell. We repair and test Walrus, EBARA, Stairs and PowerBox pumps at our workshop in Ballymount, Dublin 12, often within the same working day. Bring the pump in, or contact us to arrange it. See our services.

Yes, for pumps we've supplied that are still within their 2-year warranty, we can visit on site in Dublin. Outside warranty, bring the pump to our Ballymount workshop for repair and testing. For commercial booster sets, on-site commissioning by our engineers is available on request.