--- title: "Power Flushing in Corby & Northants | Fixed Price | Reactive" description: "Cold radiators, sludge build-up or weak heating in Corby, Kettering or Northants? Professional power flush, fixed price, completed in a day, 12-month guarantee." lang: en-GB json-ld: | [ { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "How long does a power flush take?", "acceptedAnswer": { "@type": "Answer", "text": "A standard 8-radiator system: a single working day, typically 6–8 hours including pre-clean, flush, neutralise, refill and certify. Larger systems or commercial sites need a full day plus." } }, { "@type": "Question", "name": "Do you take radiators off the wall?", "acceptedAnswer": { "@type": "Answer", "text": "Generally no — flushing is in-situ via the boiler return. Occasionally a totally sludged radiator needs removing for an external flush, but we'll tell you in the survey if so." } }, { "@type": "Question", "name": "Will a power flush damage my old radiators?", "acceptedAnswer": { "@type": "Answer", "text": "Not done correctly. We use low-pressure, high-velocity flow specifically because high pressure can damage older fittings. Cast-iron radiators in heritage properties need extra care — we adjust the dwell pressure accordingly." } }, { "@type": "Question", "name": "How often should I power flush?", "acceptedAnswer": { "@type": "Answer", "text": "Once every 8–10 years on a maintained system, or before fitting a new boiler to an older heating circuit. With a magnetic filter and annual inhibitor checks, you can extend that interval significantly." } }, { "@type": "Question", "name": "Will it definitely fix my cold radiators?", "acceptedAnswer": { "@type": "Answer", "text": "If the cause is sludge, yes — and we test for that during the survey. If your radiator is cold because of air, a stuck TRV, an undersized rad or a circulation problem, a flush won't fix it. We'll tell you before you pay." } }, { "@type": "Question", "name": "Is the work guaranteed?", "acceptedAnswer": { "@type": "Answer", "text": "12-month workmanship guarantee on the flush itself, plus a written cleanliness certificate that satisfies most boiler manufacturer warranty requirements." } }, { "@type": "Question", "name": "Should I fit a MagnaClean filter at the same time?", "acceptedAnswer": { "@type": "Answer", "text": "Strongly recommended, especially on older systems. A magnetic filter is a small fixed-price add-on that catches any future magnetite before it re-settles in radiators — the single biggest predictor of how long a flush will last." } }, { "@type": "Question", "name": "Will my heating bills go down?", "acceptedAnswer": { "@type": "Answer", "text": "Most customers see 10–25% gas reduction in the first heating season after a flush — bigger savings on the worst-affected systems. Restored radiator output means shorter boiler run times." } } ] }, { "@context": "https://schema.org", "@type": "Service", "@id": "https://reactiveplumbing.co.uk/power-flushing#service", "name": "Power Flushing in Corby & Northants", "serviceType": "Power Flushing in Corby & Northants", "description": "Cold radiators, sludge build-up or weak heating in Corby, Kettering or Northants? Professional power flush, fixed price, completed in a day, 12-month guarantee.", "url": "https://reactiveplumbing.co.uk/power-flushing", "provider": { "@id": "https://reactiveplumbing.co.uk/#localbusiness" }, "areaServed": [ { "@type": "City", "name": "Corby" }, { "@type": "City", "name": "Kettering" }, { "@type": "City", "name": "Desborough" }, { "@type": "City", "name": "Rothwell" }, { "@type": "City", "name": "Oundle" }, { "@type": "City", "name": "Market Harborough" }, { "@type": "City", "name": "Wellingborough" }, { "@type": "City", "name": "Oakham" }, { "@type": "City", "name": "Stamford" }, { "@type": "City", "name": "Peterborough" } ], "offers": [ { "@type": "Offer", "name": "Up to 8 radiators", "priceCurrency": "GBP", "priceSpecification": { "@type": "PriceSpecification", "price": "Fixed price", "priceCurrency": "GBP" }, "description": "Standard combi or system boiler. MagnaCleanse process, X100 inhibitor refresh, certificate — quoted before work starts." }, { "@type": "Offer", "name": "9–12 radiators", "priceCurrency": "GBP", "priceSpecification": { "@type": "PriceSpecification", "price": "Fixed price", "priceCurrency": "GBP" }, "description": "Larger family home or extended system. Same process, longer dwell, larger inhibitor dose." }, { "@type": "Offer", "name": "13+ radiators or commercial", "priceCurrency": "GBP", "priceSpecification": { "@type": "PriceSpecification", "price": "Quoted on survey", "priceCurrency": "GBP" }, "description": "Site survey first. Includes mid-rinse flush stage and per-zone isolation as needed." } ] }, { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://reactiveplumbing.co.uk" }, { "@type": "ListItem", "position": 2, "name": "Plumbing Services", "item": "https://reactiveplumbing.co.uk/plumbing-services" }, { "@type": "ListItem", "position": 3, "name": "Power Flushing in Corby & Northants", "item": "https://reactiveplumbing.co.uk/power-flushing" } ] }, { "@context": "https://schema.org", "@type": "Person", "name": "Carl Eddershaw", "jobTitle": "Director & Lead Engineer", "worksFor": { "@id": "https://reactiveplumbing.co.uk/#localbusiness" }, "knowsAbout": [ "Gas Safe Registered", "OFTEC Registered", "MagnaCleanse trained", "Manufacturer-approved chemical regimen", "12-month workmanship guarantee" ] } ] --- Gas Safe Registered · OFTEC Registered · Checkatrade Verified 9 Rutherford Court, Corby NN17 4SJ [info@reactiveph.co.uk](mailto:info@reactiveph.co.uk) [![Reactive Gas Heating & Plumbing logo](/__l5e/assets-v1/51d713a4-18a4-4b5f-96fb-2fcce169e56c/reactive-logo.png)](/) ServicesAreasGuides[About](/about)[Our Work](/our-work)[Plans](/maintenance-plans)[Reviews](/reviews)[Contact](/contact) [24/7 Call 07915 906262 ](tel:+447915906262)[Fixed Boiler Quote](/boiler-quote) 1. [Home](/) 2. [Plumbing Services](/plumbing-services) 3. Power Flushing Plumbing Services # Power Flushing in Corbycold radiators back to fully hot in a single day, fixed price If radiators are cold at the bottom, your boiler clicks off and on, or your heating bills have crept up — sludge in the system is the usual cause. We power-flush with MagnaCleanse and full inhibitor refresh, in a day, for one fixed price. [Enquire Now](/contact) [Call 07915 906262](tel:+447915906262) - Completed in a single day - MagnaCleanse-grade kit - Inhibitor refresh included - 12-month workmanship guarantee 1 day Average job time 20+°C Typical radiator temp gain Up to 25% Heating efficiency recovered 12 mo Workmanship guarantee Power flushing — combi, system & open-vented ## What a proper power flush actually does — and what it doesn't A power flush forces water and a chemical cleaner through your central heating system at high velocity but low pressure, breaking up the magnetite sludge and limescale that's coating the inside of your radiators and pipework. Done properly, you get hot radiators top-to-bottom, faster heat-up, lower gas consumption and a quieter boiler. Done badly — too low pressure, too short a dwell time, no proper neutraliser, no inhibitor refresh — it's barely better than a manual drain-down. We use the MagnaCleanse process, dwell each radiator individually, and refill with fresh inhibitor at the manufacturer-specified concentration. Every job ends with a TDS (total dissolved solids) reading to prove the system is genuinely clean. It is not a fix for: undersized radiators, frozen condensate pipes, faulty diverter valves, or boilers at end of life. We'll tell you honestly during the survey whether a flush will solve your symptom — or whether something else needs sorting first. What happens if you wait ## Sludge isn't a maintenance issue — it's an efficiency tax Magnetite sludge builds up in every wet central heating system. After 8–12 years it lines the inside of every radiator, narrows pipework bores, blocks heat exchangers and forces your boiler to work harder for the same heat. The cost is invisible — until you compare bills before and after a flush. Worse, sludge accelerates boiler component failure: pumps seize, diverter valves stick, plate heat exchangers block, and warranty claims get rejected because the system wasn't kept clean. - Cold spots at bottom of radiators (sludge) or at the top (air) - Boiler kettling — banging or whining as sludge restricts flow - Heat-up time noticeably longer than 5 years ago - Boiler manufacturer warranty rejected for 'system contamination' - Pump or diverter valve replaced more than once in 5 years - Black water when bleeding radiators — that's iron oxide, i.e. sludge Our process ## From first call to job done — exactly what to expect 1. 01 ### Survey & test MagnaCleanse-style flow test on each radiator + system water TDS sample. We confirm a flush will help before quoting. 2. 02 ### Pre-treatment Cleaning chemical added, system circulated for 1–2 hours to lift bonded scale and break up magnetite. 3. 03 ### Power flush Each radiator individually dwelled and reverse-flushed. Magnet captures iron oxide as it leaves. 4. 04 ### Neutralise & refill System neutralised, refilled with fresh water, dosed with inhibitor at manufacturer-specified concentration. 5. 05 ### Test & certify Pre/post TDS readings, radiator surface temperature differentials, written certificate for warranty records. Why customers choose Reactive ## No guesswork. No upsell. Just the work, done right. - ### Cuts heating bills Restored radiator output means shorter run times. Customers report 10–25% gas savings post-flush. - ### Protects boiler warranty Most warranties require system cleanliness. Our written certificate satisfies manufacturer requirements. - ### Done in a single day Standard 8-rad system flushed and back in service same day. We don't drag it out across visits. - ### MagnaCleanse process Industry-recognised cleaning method with proper dwell times — not a quick mains-pressure flush. - ### Inhibitor refresh included Sentinel X100 (or equivalent) at manufacturer-spec dose. Without this, sludge re-forms within 2 years. - ### Honest 'don't bother' if it won't help If your symptom is undersized rads or a failing pump, we'll tell you before you pay for a flush you don't need. ![Detailed view of central heating system components including pump and diverter valve, showing components vulnerable to sludge](/__l5e/assets-v1/20bb6542-a0f0-4f48-8177-13f7835b3333/img-006.jpeg) In detail ## What's actually inside your heating system — and why it matters The black goo that comes out when you bleed an old radiator is magnetite — iron oxide formed by the corrosion of steel radiator panels in oxygen-rich water. Every wet central heating system creates it. Inhibitor (Sentinel X100, Fernox F1, etc.) suppresses corrosion but degrades over time and gets washed out when the system is opened up for repairs. By 8 years post-installation, an unmaintained system typically has 3–5kg of sludge sitting in radiators and low points of the pipework. By 12 years, that figure can double. The sludge isn't dangerous, but it kills heating efficiency: a sludged radiator might output 60% of its rated kW, meaning the boiler runs 40% longer to compensate. Power flushing is the only effective way to remove bonded magnetite once it's built up. Magnetic system filters (MagnaClean, Adey ProTwo) catch new magnetite as it forms, but they can't shift what's already settled. Best practice: flush at install, fit a magnetic filter, refresh inhibitor every 5 years, service annually. - ### Combi boiler systems Plate heat exchangers are most vulnerable to sludge — flushing pre-empts costly PHE replacement. - ### System & open-vented Larger water content, more sludge accumulates over time. Flushing is more involved but more impactful. - ### Underfloor heating UFH manifolds need careful flushing — we flush per-loop, not whole-system blast. - ### Old cast-iron radiators Heritage rads can be flushed but need extra care on dwell pressure. We've done plenty in Oundle and Stamford. - ### Magnetic filter fitting MagnaClean Pro2 fitted at the same time — captures any future magnetite before it settles in radiators. - ### Inhibitor regimen Sentinel X100 / Fernox F1 at install dose. Re-test inhibitor concentration at every annual service. Honest pricing ## How much does a power flush cost in Corby & Northants? Pricing is per number of radiators on the system. Includes pre-clean, full power flush, neutraliser, fresh inhibitor and a written cleanliness certificate. Up to 8 radiators Fixed price Standard combi or system boiler. MagnaCleanse process, X100 inhibitor refresh, certificate — quoted before work starts. 9–12 radiators Fixed price Larger family home or extended system. Same process, longer dwell, larger inhibitor dose. 13+ radiators or commercial Quoted on survey Site survey first. Includes mid-rinse flush stage and per-zone isolation as needed. ### What changes the price - Number of radiators on the system - System type (combi, system, open-vented, sealed) - Severity of sludge (light, moderate, heavy) - Whether a magnetic filter is being fitted at the same time (supplied & fitted as a fixed-price add-on) - Access to the boiler and radiators - Whether old cast-iron radiators need extra-careful low-pressure dwell Free, fixed-price quote — no obligation, no callout fee. [Get my fixed price](/contact) Areas covered ## Local cover across Northants & Rutland Power flushing is a particularly common ask across the older housing stock in Corby town centre, the village stone properties around Oundle and Oakham, and the Kettering 1990s estates that are now reaching the 20-year sludge tipping point. We cover all of it from the same fixed-price model. - [Power flushing in Corby ](/areas/corby) - [Central heating power flush Kettering ](/areas/kettering) - [Power flushing Oundle ](/areas/oundle) - [Heating system flush Oakham ](/areas/oakham) Who'll be doing the work ## The Reactive engineering team our team runs every flush personally with a stocked van — pump, magnet, neutraliser, inhibitor and TDS meter. We don't sub-flushes out — they go wrong too easily when handed to someone with rented kit and no follow-up incentive. - Gas Safe Registered - OFTEC Registered - MagnaCleanse trained - Manufacturer-approved chemical regimen - 12-month workmanship guarantee FAQs ## Questions we actually get asked Anything not covered here? Pick up the phone — straight talk, no salesperson in the middle. [Call 07915 906262](tel:+447915906262) ### ### How long does a power flush take? ### ### Do you take radiators off the wall? ### ### Will a power flush damage my old radiators? ### ### How often should I power flush? ### ### Will it definitely fix my cold radiators? ### ### Is the work guaranteed? ### ### Should I fit a MagnaClean filter at the same time? ### ### Will my heating bills go down? Related services [ In this category 24/7 emergency plumber ](/emergency-plumbing)[ In this category Blocked drain clearance ](/drain-unblocking)[ In this category Hidden leak tracing ](/leak-detection-repair)[ You may also need Annual boiler service ](/boiler-servicing)[ Back to hub All Plumbing Services ](/plumbing-services) Ready when you are ## Cold radiators? Whining boiler? Flush it. MagnaCleanse-grade flush, full inhibitor refresh, written certificate — completed in a single day for one fixed price. [Enquire Now](/contact) [07915 906262](tel:+447915906262) Last updated May 2026 · Reactive Gas Heating and Plumbing Services Limited · 9 Rutherford Court, Corby NN17 4SJ · Gas Safe Registered · OFTEC Registered · Checkatrade Verified [![Reactive Gas Heating & Plumbing logo](/__l5e/assets-v1/51d713a4-18a4-4b5f-96fb-2fcce169e56c/reactive-logo.png)](/) Reactive Gas Heating and Plumbing Services Limited. Plumbing, heating and gas engineers based in Corby — covering Northamptonshire, Rutland, Leicestershire and the East Midlands. [07915 906262 ](tel:+447915906262) [0800 861 1593 (freephone)](tel:+448008611593) [07488 883576](tel:+447488883576) [07342 043953](tel:+447342043953) [info@reactiveph.co.uk](mailto:info@reactiveph.co.uk) 9 Rutherford Court Corby, Northamptonshire NN17 4SJ [](https://www.facebook.com/Reactiveservices/)[](https://www.instagram.com/reactivegasheatingplumbing/) ### [Plumbing](/plumbing-services) - [Emergency Plumbing](/emergency-plumbing) - [Drain Unblocking & Drainage](/drain-unblocking) - [Leak Detection & Repair](/leak-detection-repair) - [Power Flushing](/power-flushing) ### [Heating & Gas](/heating-gas-services) - [Boiler Installation](/boiler-installation) - [Boiler Repair & Breakdown](/boiler-repair) - [Boiler Servicing](/boiler-servicing) - [LPG Installation & Servicing](/lpg-engineer) - [Oil Boiler Installation & Servicing](/oil-boiler-engineer) ### [Areas Covered](/areas) - [Corby](/areas/corby) - [Kettering](/areas/kettering) - [Desborough](/areas/desborough) - [Rothwell](/areas/rothwell) - [Oundle](/areas/oundle) - [Market Harborough](/areas/market-harborough) - [Wellingborough](/areas/wellingborough) - [Oakham](/areas/oakham) - [Stamford](/areas/stamford) - [Peterborough](/areas/peterborough) ### Company - [About our team](/about) - [Customer Reviews](/reviews) - [Recent Work](/our-work) - [Maintenance Plans](/maintenance-plans) - [Current Offers](/specials) - [Contact](/contact) - [Privacy Policy](/privacy-policy) - [Terms & Conditions](/terms-conditions) ### Opening Hours - Monday: 08:00–18:00 - Tuesday: 08:00–18:00 - Wednesday: 08:00–18:00 - Thursday: 08:00–18:00 - Friday: 08:00–18:00 - Saturday: 08:00–13:00 - Sunday: Closed - 24/7 emergency cover — call any time outside working hours ### Guides & Blog - [Combi vs System vs Regular Boilers: Which Is Right for You?](/guides/combi-vs-system-vs-regular-boilers) - [How Much Does a New Boiler Cost in 2026?](/guides/how-much-does-a-new-boiler-cost) - [8 Signs You Need a New Boiler (Not Just a Repair)](/guides/signs-you-need-a-new-boiler) - [Common Boiler Fault Codes Explained](/guides/common-boiler-fault-codes-explained) - [What to Do in a Plumbing Emergency](/guides/what-to-do-in-a-plumbing-emergency) - [How to Turn Off Your Water at the Mains](/guides/how-to-turn-off-water-at-the-mains) © 2026 Reactive Gas Heating and Plumbing Services Limited. 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