Commercial Pot Wash Sink & Pre-Rinse Spray Buying Guide: The Complete UK Guide (2026)
A commercial pot wash sink — the 3-compartment stainless steel basin found in every UK catering kitchen’s ware wash area — is the critical link between HACCP compliance and kitchen efficiency. This guide covers the decisions that matter: single vs triple-bowl layout, 304 vs 316 stainless steel choice, fixed vs hands-free tap systems, water flow regulations, and sourcing across the leading UK trade brands. Craven Cooling specifies the right brand sink to your kitchen — not just the cheapest option.
- HACCP 3-compartment workflow: Regulation (EC) 852/2004 requires food businesses to have adequate cleaning and disinfection facilities and a sufficient supply of hot and cold water. As recommended best practice, pre-rinse soiled items, hot wash with detergent at around 65°C, then hot rinse at around 77°C and air dry. Single-bowl sinks struggle to keep the wash stages separate in high-volume kitchens; a double-bowl suits small catering; a triple-bowl is best practice for pubs, restaurants, schools and hospitals.
- Bowl sizing standard: single 600 mm wide (135 L capacity), double 1200 mm (220 L each bowl), triple 1800 mm (270 L each bowl). Depth 250–300 mm for saucepans; 400 mm+ for stockpots and trays. Drainer lip 200 mm prevents cross-contamination between clean and soiled.
- Stainless steel grade: 304-grade (18/10 chrome/nickel) is UK trade standard — resists chlorine-based detergents and ambient moisture. 316-grade (16/10 + 2% molybdenum) for high-corrosion zones (strong acids, coastal, chemical kitchens). Cost premium 15–22% for 316.
- Gauge and durability: 1.0 mm gauge minimum (thin, dents easily); 1.2 mm gauge preferred for trade use; 1.5 mm+ for institutional high-volume. Thicker gauge = flatter bowls, longer service life, better heat retention.
- Pre-rinse spray flow rate compliance: Water Regulations 1999 (as amended 2021) aim to prevent the waste of water; a water-efficient pre-rinse spray of around 6 L/min at the spray head is the modern benchmark, while older, higher-flow sprays (around 12–15 L/min) use more water and cost more to run. Hose length 4–6 feet typical. WRAS (Water Regulations Advisory Scheme) approval mandatory — check product certificate before purchase.
- Tap system options: fixed single-lever mixer (cost-effective), swivel mixer with spray hose (pre-rinse capability), dual separate hot/cold for manual mixing (low cost, high labour), sensor-operated hands-free (mandatory for wash-hand sinks under BS EN 200; optional for pot wash but advised for EHO compliance). Knee-operated foot pedal alternative for hands-free.
- UK price tiers (ex VAT, April 2026): single bowl no taps £180–£280; double bowl + drainer + mixer £400–£650; triple HACCP-approved sink + drainer + taps £900–£1,400; specialist heavy-duty (Sissons, Pland) triple + pre-rinse arm £1,800–£3,500+. Pre-rinse spray unit standalone £120–£350.
- Lead time and compliance: stocked UK brands (Inomak, Vogue, Parry) ship 5–10 working days; bespoke sizes/finishes 4–8 weeks. WRAS certification required for all taps and pre-rinse spray heads. EHO (Environmental Health Officer) inspection standard: Water Regulations approval visible, drain trap accessible, handwashing sink separate with soap/towel dispensers, backflow prevention in pre-rinse line.
The pot wash sink is one of the least glamorous pieces of kitchen equipment and one of the most critical for food safety. It sits at the boundary between dirty and clean: pre-rinse on the left, detergent wash in the middle, hot rinse on the right. Miss the temperature, miss the soap, or use the wrong bowl sequence, and you’ve broken HACCP. Specify the wrong sink — a single bowl in a 150-cover pub, or a thin-gauge unit that flexes under the weight of stockpots — and you’ve bought yourself ten years of dented basins, cross-contamination risk, and drain blockages.
This guide is written for the kitchen manager, head chef, or catering operator making that sink decision for the first time. We cover the HACCP workflow in plain English, the stainless steel choice nobody explains clearly, the water flow regulations that changed in 2021, and how to source across the leading UK multi-brand range. Craven Cooling specifies sinks to your kitchen — not just lists products. Browse the full commercial pot wash and ware wash range now →
- The HACCP 3-compartment workflow explained
- Bowl sizing and stainless steel grade choice
- Water flow compliance and WRAS-approved taps
- Pre-rinse spray systems and backflow prevention
- Multi-brand product cards — Inomak, Vogue, Sissons, Pland, Parry, T&S Brass, Fisher, Mechline
- UK price tiers: entry single-bowl to specialist triple-compartment
- 10-year total cost of ownership calculation
- UK compliance checklist (Water Regs, HACCP, BS EN standards)
- Installation and use checklist
- FAQ — eight critical buying questions answered
Decision 1: Single, Double, or Triple Bowl?
The bowl count is determined by your kitchen’s ware wash volume and regulatory requirement. HACCP rules separate soiled from clean; your bowl layout enforces that separation.
| Configuration | Dimensions | Capacity | HACCP suitability | Suitable for |
|---|---|---|---|---|
| Single bowl | 600 mm wide × 600 mm deep × 300 mm H | 135 L | Not recommended | Small prep kitchens, personal use, staff meal stations only |
| Double bowl | 1200 mm wide, two 550 mm bowls | 220 L per bowl | Conditional: small catering only | Micro-catering, small sandwich shops, kiosks (must demonstrate single-use mitigation) |
| Triple bowl + drainer | 1800 mm wide, three 550 mm bowls + 400 mm drainer | 270 L per bowl | Best practice | Pubs, restaurants, schools, hospitals, catering units, care homes (all registered food businesses) |
Decision 2: 304 vs 316 Stainless Steel Grade
Stainless steel grade determines how long your sink resists the chemical and thermal stress of daily ware wash.
| Grade | Composition | Corrosion Resistance | Cost (relative) | Best for |
|---|---|---|---|---|
| 304 (18/10) | 18% chromium, 10% nickel | Good vs detergents, chlorine, normal tap water | 1.0× | Standard UK kitchen ware wash, most applications |
| 316 (16/10 + 2% Mo) | 16% chromium, 10% nickel, 2% molybdenum | Excellent vs chlorides, strong acids, marine salt spray | 1.15–1.22× | Coastal kitchens, chemical-heavy prep (citrus acid tanks), aggressive detergent environments |
| 430 (ferritic) | 16–18% chromium, no nickel | Poor vs detergent chlorine, rusts easily | 0.6–0.7× | Budget import sinks; avoid for ware wash (stain risk) |
For 90% of UK kitchens, 304 stainless is the right choice. The 15–22% cost premium for 316 is justified only if your kitchen uses strong chemical cleaning agents (citric acid descalers, bleach-based sanitizers) or is in a high-salt environment (coastal hospitality). Standard chlorine-based detergents and hot water do not require 316.
Decision 3: Fixed Tap, Swivel Mixer, or Hands-Free?
The tap system determines water control, pre-rinse capability, and labour efficiency. It also triggers regulatory requirements for wash-hand sinks.
| Tap Type | Operation | Water Control | Cost ex VAT | Best for |
|---|---|---|---|---|
| Fixed single-lever mixer | Manual lever, hot/cold blend | Manual on/off, adjustable temperature | £80–£140 | Budget conscious, small kitchens, low-volume ware wash |
| Swivel mixer with spray hose | Manual lever + detachable spray head on hose | Spray mode (6 L/min compliant) + fill mode | £180–£280 | Pre-rinse capability, standard UK ware wash, pubs & restaurants |
| Dual separate taps (hot + cold) | Two manual taps, user mixes at basin | No spray head; manual blending required | £60–£100 | Budget option, non-compliant for efficient pre-rinse, rarely specified |
| Sensor hands-free (optional for pot wash) | Sensor activation, automatic shutoff | No manual touching, water-saving, WRAS-approved | £220–£420 | High-traffic kitchens, staff hygiene emphasis, EHO compliance focus |
| Knee-operated foot pedal (hands-free alternative) | Foot pedal under basin, hands-free operation | Reliable, no sensor batteries, WRAS-approved | £140–£220 | Preferred alternative where sensors cause maintenance issues |
Sink Design: Bowl Depth, Drainer Lip, and Drain Trap
Bowl depth matters: Standard pots, pans, and smaller hotel pans fit in 250–300 mm depth. Stockpots, large braising pans, and sheet trays require 350–400 mm depth. A sink specified at 250 mm will have staff hand-washing oversized items outside the basin — water spillage, hygiene risk, cross-contamination. Always ask for your tallest piece of equipment to be demonstrated in the sink before order.
Drainer surface and lip: The drainer (drain board) should be sloped toward the main sink at 1–2 degrees and feature a lip of 150–200 mm to prevent dirty water from dripping back onto clean items. Grooved stainless drainers are preferred — smooth surfaces pool water and bacteria.
Drain trap and grease management: Commercial pot wash sinks require a removable strainer basket (catches food waste, prevents blockage) and a U-bend trap below. Many kitchens forget to empty the basket daily — blockages occur within months. Some local councils classify kitchen wastewater as “trade effluent” under the Water Industry Act 1991 if fats, oils, and grease (FOG) exceed 500 mg/L; this triggers grease separator requirements. Always check with your water authority before installation.
UK Price Tiers: Entry to Specialist
The entry tier is not recommended for registered food businesses — it fails HACCP workflow. The mid-range suits small catering, sandwich shops, and office kitchens. Professional-grade triple sinks are the recommended choice for pubs, restaurants, schools, and care homes. Specialist heavy-duty sinks are chosen when you’re specifying a kitchen for a new build or major refurb and want longevity beyond 15 years.
Multi-Brand Product Selection: Who to Specify
The UK pot wash sink market is dominated by a small number of reliable trade brands. Craven Cooling sources from the full range — you choose the brand that suits your budget and use case.
- 1800 mm W × 700 mm D × 850 mm H
- Three 550 mm bowls, 270 L each
- 304 stainless, 1.0 mm gauge
- Drainer left or right, grooved surface
- Manual basin mixer (tap not included)
Inomak PSC is the workhorse triple sink for entry-level pub and restaurant ware wash. Solid 304 stainless, compliant bowl depth. Lower gauge (1.0 mm) than premium brands means flexing under heavy stockpot load — acceptable for lower-volume use. Drainer prevents cross-contamination between clean and soiled bowls. Tap supplied separately (see specialist cards below).
View Inomak Range- 1800 mm W × 700 mm D × 850 mm H
- Three 550 mm bowls, 270 L each
- 304 stainless, 1.2 mm gauge
- Reinforced legs with cross-brace
- Option: double bowl 1200 mm (£680)
Vogue is the UK’s most-specified brand in mid-market restaurants and pubs. 1.2 mm gauge means flatter, more durable bowls — less flex under loaded service. Reinforced leg bracing resists wobble on uneven kitchen floors. Available in both triple and double configurations. Recommended for high-frequency ware wash. Tap sourced separately.
View Vogue Range- 1800 mm W × 700 mm D × 850 mm H
- Three 600 mm bowls (extra capacity)
- 304 or 316 grade, 1.5 mm gauge
- Deep drainer lip, polished finish
- Factory build in Birmingham since 1889
Sissons manufactures in the UK and is the premium choice for kitchens specifying durability over 20+ years. Heavier gauge (1.5 mm), larger bowls, and precision engineering mean zero flex and excellent heat retention. 316 stainless option available for chemical-intensive kitchens. Lead time 6–8 weeks for standard configurations. Premium price reflects British build quality and warranty.
View Sissons Range- 1800 mm W × 700 mm D × 850 mm H
- Three 550 mm bowls, 270 L each
- 304 stainless, 1.2 mm gauge
- Integrated pre-rinse swing arm (6 L/min WRAS)
- Foot-pedal tap option (hands-free)
Pland is a UK commercial catering specialist offering integrated pre-rinse arms — spray mounted above the left (soiled) bowl on an articulated arm. Saves space and handles spray deployment efficiently. WRAS-approved head at 6 L/min compliant with 2021 Water Regulations. Foot-pedal tap alternative preferred over sensor for reliability in high-traffic kitchens. Ideal for pubs and mid-volume restaurants where integrated pre-rinse matters.
View Pland Range- 1800 mm W × 700 mm D × 850 mm H
- Three 550 mm bowls, 270 L each
- 304 stainless, 1.2 mm gauge
- Splashback and adjustable shelving options
- Double-bowl option available (£720)
Parry supplies educational, care, and hospitality institutions across the UK. Triple sink is standard institutional spec — tried and tested in schools, care homes, and hospital kitchens. Splashback option prevents water spray to wall surface. Robust construction suitable for high-throughput ware wash. Good value for institutional kitchens; less premium branding than Sissons but reliable performance.
View Parry Range- 6 L/min WRAS-approved spray head
- Flexible hose 4–6 feet, stainless braid
- Backflow preventer (check valve) included
- Swivel mount for basin rim or wall
- T&S Brass, Fisher, Mechline options
If your existing pot wash sink lacks a pre-rinse spray, a standalone upgrade brings Water Regulations 1999 compliance without full sink replacement. Retrofit cost £145–£320 (spray unit + installation labour). WRAS approval mandatory — check product certificate. Backflow prevention is critical to prevent contaminated water flowing back to mains supply. Budget 2–3 hours labour for plumber to install and test.
View Pre-Rinse OptionsTap & Pre-Rinse Spray Brands: The Secondary Market
Once you’ve selected your sink, the tap and pre-rinse spray are your next critical choices. Three brands dominate this market.
T&S Brass (US Premium)
Pre-rinse specialist- B-0123 / B-0133 low-flow spray heads (6 L/min WRAS)
- Pressure-assist technology for efficient rinsing
- Cost: £280–£420 per unit
- Lead time: 5–7 working days (stocked by major UK distributors)
- Best for: High-volume ware wash, large kitchens, hospitals, schools
Fisher (US Heritage)
Commercial kitchen standard- Swing-spout pre-rinse spray with detent handle
- 6 L/min compliant, reinforced hose
- Cost: £200–£320 per unit
- Lead time: 7–10 working days
- Best for: Mid-range restaurants, pubs, standard kitchens
Mechline AquaJet (UK Budget)
UK value option- 6 L/min WRAS-approved spray head
- Simple lever-operated, no bells
- Cost: £120–£180 per unit
- Lead time: 3–5 working days
- Best for: Budget-conscious kitchens, micro-catering, staff ware wash
All three brands deliver WRAS-approved, 6 L/min compliant systems. T&S and Fisher are premium (US import, superior engineering); Mechline is UK budget. For most pubs and restaurants, Fisher is the sweet spot: proven in UK service, good availability, mid-tier cost.
Water Flow and Water Efficiency
Modern water-efficiency guidance points to commercial pre-rinse spray heads of around 6 L/min at the nozzle. This water-efficiency benchmark is now standard on new kitchen equipment, and a lower flow rate means lower water and energy costs.
Why it matters: Old systems (12–15 L/min) waste water and increase effluent disposal cost. A kitchen replacing a 12 L/min spray with a 6 L/min WRAS-approved unit saves approximately 69,000 litres annually — roughly £89 at 2026 non-domestic water rates. Payback period is 18–24 months on the equipment cost alone.
What to check: Always request the WRAS approval certificate from the supplier. Do not accept claims of “6 L/min equivalent” or “meets standards” — demand the physical certificate. Installation must include a backflow preventer (check valve) to prevent contaminated ware wash water flowing back into the mains supply. This is a health protection measure mandated by environmental health officers.
10-Year Total Cost of Ownership Calculation
Capital: £1,440 | Operating: £2,370 | Residual sink value (year 10): negligible
Comparison scenario: An older pre-2021 3-compartment sink with high-flow 12 L/min spray (not included in purchase). Year 1 capital £1,080 (cheaper unit, no spray upgrade). But 10-year water costs run 2× higher (192 L/day savings lost), amounting to £1,780 additional drainage expense. Regulatory risk: non-compliance flagged in EHO inspection may require forced upgrade mid-service cycle (fines + emergency capital). True 10-year cost of the “cheaper” option approaches £3,900+.
UK Compliance Checklist
- Water Regulations 1999 (as amended 2021) — for water efficiency, choose a pre-rinse spray head of around 6 L/min at the nozzle. Request WRAS approval certificate from supplier before purchase. Backflow prevention (check valve) mandatory to prevent contamination of mains supply.
- Regulation (EC) 852/2004 — HACCP for catering — A three-compartment sink is the recommended setup for registered food businesses: the HACCP best-practice workflow is a pre-rinse (soiled), a hot detergent wash at around 65°C and a final rinse at around 77°C. Triple-bowl physical separation enforces this workflow and prevents cross-contamination flagged by Environmental Health Officers.
- BS EN 12215 — Specification for sinks — Commercial stainless steel sinks must meet dimensional and material standards. Verify your sink supplier references BS EN 12215 compliance in product data sheet.
- BS EN 200 — Specification of taps and tap combinations — Wash-hand sinks require hands-free operation (sensor or foot-pedal) to prevent bacterial cross-contamination. Pot wash sinks do not mandate hands-free, but EHO guidance increasingly recommends it for staff hygiene.
- Water Industry Act 1991 — Trade effluent classification — Some local councils classify kitchen wastewater as “trade effluent” if fats, oils, grease (FOG) exceed 500 mg/L. This triggers grease separator requirements. Always check with your water authority; Craven Cooling can advise on grease management for your kitchen type.
- Environmental Health Act 1990 & Food Safety Act 1990 — EHO has power to inspect kitchens and issue compliance notices. Poorly equipped ware wash (an undersized single bowl in a high-volume kitchen, a missing final hot rinse, or no backflow prevention) is a priority inspection item. Failure to remedy triggers closure orders.
- WRAS approval scheme — The Water Regulations Advisory Scheme certifies products (taps, spray heads, valves) for use in UK water supply systems. All pre-rinse spray heads must carry WRAS approval mark. No WRAS mark = non-compliant installation and insurance/EHO risk.
- Drain trap & grease management — Install removable strainer basket to prevent blockages. Empty daily. If local water authority classifies your kitchen as trade effluent source, grease separator maintenance is mandatory. Monthly clean-out of U-bend and basket prevents drain collapse.
Installation & Use Checklist
- Sink positioning in kitchen layout — Place in ware wash zone, separate from raw food prep areas (Regulation 852/2004). Distance from raw meat surface minimum 1 metre (recommended 2 metres). Hot water supply dedicated, not shared with hand-wash sink. Check local building regulations for ventilation hood requirement above sink.
- Water supply commissioning — Cold inlet supply minimum 20 L/min at 2 bar pressure (required for pre-rinse spray efficiency). Hot supply minimum 60°C at inlet, thermostatic mixer maintains 77°C at tap outlet for final rinse. Plumber must test and certify water temperature in writing before kitchen goes live.
- Backflow prevention installation & testing — Check valve must be installed and tested by qualified plumber. Testing certificate must be retained (3-year retention for insurance). Some local water authorities require annual certification of backflow prevention — check your authority’s requirement.
- Staff training on HACCP ware wash workflow — Pre-rinse bowl (left), hot wash with detergent in middle bowl, final hot rinse (right), air dry on drainer. Timing: pre-rinse 20 seconds, wash minimum 2 minutes at 65°C, final rinse minimum 1 minute at 77°C. Train new kitchen staff on this sequence — failure to follow workflow voids food safety assurance.
- Drain basket and trap maintenance schedule — Empty strainer basket daily at end of service. Run hot water flush through drain to clear food debris. Monthly: remove U-bend trap, clean thoroughly, check for FOG buildup. Quarterly: inspect for leaks or corrosion at union nuts.
- Temperature monitoring and verification — Use calibrated kitchen thermometer to spot-check tap water temperature weekly (cold inlet ~12°C, hot outlet 77–82°C). If below 77°C at final rinse tap, inform plumber immediately — thermostat may need adjustment. Keep temperature log for 2 weeks before EHO inspection.
- Pre-rinse spray maintenance — Check spray head nozzle monthly for blockage (limescale in hard water areas). Soak in white vinegar if flow reduces. Inspect hose monthly for cracks or kinks. Replace washers in handle if spray flow becomes weak (common year 2–3 wear item).
- EHO inspection readiness — Ensure WRAS approval certificates for tap and spray head are visible on sink unit or in kitchen manual. Verify backflow prevention installation in writing from plumber. Confirm drain access is clear for inspection. Have staff demonstrate HACCP 3-bowl workflow on request. Missing documentation = compliance failure during inspection.
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A compliant commercial pot wash sink is the practical foundation of HACCP food safety in UK catering kitchens. This guide covers the three critical decisions: triple-bowl layout (recommended best practice for pubs and restaurants), 304 vs 316 stainless steel grade (304 sufficient for standard kitchens, 316 for chemical-intensive prep), and water efficiency (a WRAS-approved pre-rinse spray of around 6 L/min). We profile five leading UK brands — Inomak for value entry, Vogue for mid-market standard, Sissons for British heritage build-to-order, Pland for integrated pre-rinse arms, and Parry for institutional kitchens — plus pricing from £890 to £1,700+ for triple-compartment sinks. 10-year total cost of ownership for a compliant triple sink, tap, and spray system runs £3,800–£4,200 ex VAT including capital and operating costs; non-compliant older systems cost more over time due to water waste and regulatory risk. Installation must include backflow prevention (mandatory under Water Regulations 1999) and staff training on HACCP pre-rinse → wash → rinse workflow. Craven Cooling sources from the full multi-brand range and specifies to your kitchen type; call 01792 732702 for a kitchen survey and recommendation.
Frequently Asked Questions
Not recommended for a busy kitchen. For an effective wash, rinse and sanitise routine, best practice is to physically separate the soiled, wash and rinse stages to prevent cross-contamination. A double-bowl sink forces staff to combine the detergent wash and hot rinse in one bowl, which makes that separation harder to maintain. A triple-bowl sink is considered best practice for pubs, restaurants, schools, care homes, and all registered food businesses. A double bowl is only acceptable for very small catering operations (sandwich shop, small office kitchen) with documented EHO sign-off confirming low-volume mitigation.
304 stainless (18% chromium, 10% nickel) is the UK trade standard for pot wash sinks. It resists chlorine-based detergents, hot water, and normal tap water indefinitely. 316 stainless adds 2% molybdenum, improving resistance to very aggressive chemicals (strong acids like citric acid, bleach-based sanitizers) and coastal salt spray. The cost premium is 15–22%. For most UK kitchens using standard chlorine detergents, 304 is sufficient and recommended. Specify 316 only if your kitchen uses strong chemical cleaners (citric acid descalers, aggressive bleach) or is in a high-salt environment (coastal hospitality). Speak to your supplier about your cleaning agents if unsure.
No. You can retrofit a standalone pre-rinse spray unit (WRAS-approved, 6 L/min) for £145–£320 plus plumbing labour (2–3 hours at £55/hr = roughly £110–£165). Total upgrade cost £260–£485. This brings your sink into Water Regulations 2021 compliance without full replacement. The retrofit must include backflow prevention (check valve) to prevent contaminated water flowing back to the mains — this is mandatory for health protection. A plumber can install and test this in a single day. This is the cost-effective path if your existing sink is structurally sound and meets HACCP bowl requirements.
Regulation (EC) 852/2004 requires clean, disinfected equipment and an adequate supply of hot and cold water; it does not set a specific rinse temperature. As HACCP best practice, aim for a final hot rinse around 77°C to help kill pathogens (Listeria, Salmonella, E. coli O157:H7). If your hot water cannot reliably reach around 77°C at the tap, it is worth upgrading so you can hit recommended wash temperatures. Solutions: (1) Install a thermostatic mixer valve to boost temperature from existing supply, (2) upgrade the boiler to a larger capacity unit (if current boiler undersized), (3) insulate hot water pipes to reduce heat loss. Ask a plumber to measure your actual hot water temperature at the rinse tap with a calibrated thermometer. If below 77°C, inform your supplier or plumber immediately — this must be fixed before service. Your EHO will test this during inspection.
Backflow prevention (a check valve) is mandatory under the Water Regulations 1999 and is tested by Environmental Health Officers during inspection. Its purpose is to prevent contaminated ware wash water from flowing back into the mains water supply if pressure drops. Without backflow prevention, a blocked ware wash drain or pressure surge could theoretically push dirty water into drinking water pipes — a serious public health risk. Missing backflow prevention is a compliance failure that can result in (1) EHO enforcement notice, (2) kitchen closure order, (3) insurance claim denial if water contamination occurs. All reputable pre-rinse spray suppliers include backflow prevention built-in or as a separate inline unit. When you purchase a spray head, confirm the supplier provides the check valve and that a plumber installs and tests it. Request a testing certificate for your records.
The strainer basket (the mesh insert that catches food debris) should be emptied daily at the end of service. It does not need to be replaced unless damaged (holes in the mesh). The U-bend trap below the sink should be inspected monthly; if fats, oils, grease (FOG) have built up, remove the trap, clean it thoroughly with hot water and a stiff brush, and reinstall. In kitchens using heavy oil-based cooking (deep fry, roasting), monthly cleaning may be insufficient — clean weekly or every 5 days if blockage risk is high. A blocked trap causes water backflow into the sink during service, forcing manual bail-out and creating health hazards. Replace the rubber washers at the union nuts if leaks develop (common wear item year 2–3). If the trap corrodes or cracks, replace with a new stainless steel trap (£40–£80 part + labour).
Some local water authorities classify kitchen wastewater as "trade effluent" if fats, oils, grease (FOG) exceed 500 mg/L, which triggers grease separator requirements under the Water Industry Act 1991. This is common in kitchens using heavy oil-based cooking (fish & chip shops, deep-fry stations, pizza kitchens) or in areas with combined sewer systems. A grease separator is a large underground tank installed between the sink drain and the sewer connection; it traps FOG and allows it to solidify, preventing blockages in the public sewer system. Maintenance involves quarterly pumping out of the accumulated grease (cost £200–£400 per pump-out). Not all councils enforce this — some only require it for high-FOG kitchens. Contact your water authority directly to confirm whether your kitchen is classified as trade effluent. Craven Cooling can advise on grease management if required for your location.
Gauge refers to the thickness of the stainless steel sheet in the sink bowls. Standard options are 1.0 mm (thin, budget), 1.2 mm (mid-range, recommended), and 1.5 mm+ (heavy-duty, premium). A 1.0 mm gauge sink flexes noticeably under the weight of a full stockpot — bowls dent easily and may not drain flat. A 1.2 mm gauge bowl holds its shape under load and is the recommended trade standard. A 1.5 mm gauge (premium brands like Sissons) is substantially more durable and lasts longer (15–20 years vs 10–12 years for 1.0 mm), but costs 20–30% more. For a pub or restaurant expecting 10+ years of service, 1.2 mm is the sweet spot. For high-volume institutional kitchens (schools, hospitals, care homes), 1.5 mm is worth the premium for durability and warranty.
