When a pump is unavoidable

Typical Israeli scenarios

• Bathroom in a basement / mamad. The city sewer runs above floor level — gravity drainage is impossible.
• Laundry below the riser. Washer and dryer in a below-grade villa room.
• Garden יחידת דיור. A guesthouse 15–40 m from the main line with the wrong slope.
• Poolside shower. The drain point next to a pool often sits below the nearest manhole.
• Storage turned into a bathroom. A מחסן converted to a guest toilet with sink.
• Distant drain point. Gravity theoretically works, but the slope is under 1% — a pump is more reliable.

When a pump is not needed

• A standard apartment in a high-rise — the drain flows by gravity into the building riser.
• Ground-floor bathroom in a villa with a slope toward the plot.
• Occasional small drain (garage sink without a toilet) — a smaller utility pump may suffice.

Pump types

1. Grinder pump (טוחן). The cutting assembly pulps solids. Handles toilet, bidet and shower. Allows a discharge line as small as 32–40 mm. Pump cost 2,200–6,000 ILS.
2. Effluent pump (no grinder). Passes solids up to 35–50 mm through a 50 mm port. More robust at high flow but needs a larger discharge line.
3. Sump pump. Grey water only (shower, sink, washer). Toilet — forbidden. 600–1,800 ILS.
4. Behind-the-toilet sanitary stations (Sanibroy, SFA, Jemix). Sit directly behind the toilet, no pit required. Convenient for a מחסן conversion or guest bathroom. 1,800–4,500 ILS.
5. Remote station with a tank (Grundfos Sololift, Wilo HiSewlift). 20–40 l tank with a grinder pump. Accepts several fixtures simultaneously.

Capacity and head

Two parameters matter — flow rate (litres per minute) and head (lift height in metres). For domestic use:

• 1 bathroom (toilet + sink + shower): 80–120 l/min, 6–8 m head. A 600–900 W unit is usually enough.
• 2 bathrooms + laundry: 150–200 l/min, 8–12 m head. A 1.1–1.5 kW pump with a 25+ l tank.
• Guesthouse 30–40 m from the manhole: count horizontal run separately (roughly 1 m of head per 10 m of pipe).
• Account for fittings — each 90° elbow adds about 1.5 m to the calculated head.

An experienced plumber must calculate the operating point against the actual schematic — not "whatever was on the shelf".

Pit and sealed chamber

For a submersible pump

• Pit size — at least 60×60×80 cm for one pump. A larger volume buffers the system and cuts start frequency.
• Sealing. The pit must be airtight — otherwise odours and groundwater ingress. Use a pre-made plastic chamber or a monolithic concrete pit with a bitumen membrane.
• Cover. Cast iron or composite, with a rubber gasket. Must be removable for service.
• Venting. A 50–75 mm vent stack runs above the roof. Without it the pump draws a vacuum and smells.

For a sanitary station

• No pit — the tank is integral.
• Sits behind or next to the toilet. Must remain accessible for service.
• Slope of the feed pipe from the toilet to the station — at least 1%.

Electrical feed and alarm

• Dedicated circuit with a 16 A breaker (most domestic pumps). Never on the shared bathroom circuit — a trip triggered by a hairdryer in the next room stops the pump.
• 30 mA RCD is mandatory — required by ת"י 1205.
• Overflow alarm. A separate float plus an audible/visual module. Triggers when water rises above the normal cut-out level. Module price 300–900 ILS. Critical for basement bathrooms — without an alarm, overflow is noticed via odour or a wet floor.
• Backup power (UPS or battery inverter). Needed for villas in areas with frequent outages. Budget 1,200–4,000 ILS.
• Smart-home alarm on the phone (Wi-Fi leak sensor plus overflow float) — 200–600 ILS per kit.

Check valve and discharge line

• Check valve is mandatory. Without it the column of water in the discharge pipe returns to the pit after shutdown — the pump cycles endlessly and burns out in 6–12 months.
• Discharge diameter — 32–50 mm depending on pump and manufacturer. Oversizing slows the flow, sediment settles, the pipe clogs.
• Material — pressure PVC or PP (regular drainage pipe is not rated for pressure).
• Routing. A vertical rise to a point above the main line, then a 2–3% fall toward the manhole. No traps or U-bends.
• Ball valve upstream of the check valve — for service without draining the whole discharge line.

Maintenance

• Quarterly — visual check, clean grease and hair off the floats.
• Annually — pull the pump, rinse the grinder, inspect the impeller, renew seals.
• Motor life — 7–12 years with correct operation. With installation mistakes — 2–4 years.
• Common failures: hair and rag wrap on the shaft, grinder clog from "flushable" wipes, float failure from grease build-up.
• Operating rules. Never flush: wet wipes (even "flushable"), cat litter, large amounts of grease, paint, construction debris.

How much it costs in Israel

• Behind-the-toilet sanitary station turnkey — 2,800–5,500 ILS (unit + install).
• Sewage pump in an existing chamber — 3,500–6,500 ILS.
• Full installation with a new pit (excavation, concrete, cover) — 5,500–12,000 ILS.
• Guesthouse system (pump + 25–40 m discharge line) — 6,500–14,000 ILS.
• Overflow alarm with a float — 300–900 ILS.
• Call-out to replace a failed pump (no chamber rework) — 1,500–3,500 ILS labour + pump cost.

Common mistakes

• "We put it on the bathroom socket." A hairdryer trips the RCD, the pump stops, the basement floods.
• No check valve. Six months in, the motor overheats and the shaft seizes.
• Toilet drain into a sump pump. The sump is rated for grey water — a week later the impeller is wrapped in hair and burned out.
• Oversized discharge (100 mm instead of 40). Sediment settles and the line blocks in 2–3 years.
• No pit vent. The apartment smells even when all traps are fine.
• No alarm. Overflow is discovered via a wet carpet.