07956 994429 020 8244 0912 INFO@DHPLUMBING.CO.UK GAS SAFE REGISTERED#180521 AboutServices Service Areas Our WorkReviewsContact 07956 994429020 8244 0912 Request EstimateQuote - Home - Services - Boiler Installation Gas Safe #1805214.9★ · 159 Google reviews30+ years local # Boiler Installation inWoolwich & Greenwich Fitted Right, Warrantied for Up to 10 Years A quiet, efficient, A-rated boiler installed by a Gas Safe engineer with over 30 years on South East London homes, lower bills, hotter showers, and the manufacturer warranty registered in your name before we leave. Request a free estimate Call 07956 994429 Call 020 8244 0912 Free fixed quote · 4.9★ from 159 Google reviews · Manufacturer warranty registered before we leave site 30+ yrs Local experience 180521 Gas Safe registered 4.9★ 159 Google reviews £5m Public liability insured 9–9 Office, 7 days a week Overview ## A new boiler, sized and fitted for how your home actually runs A boiler is the single most expensive appliance in your home and the one most likely to be sold on commission rather than specified on merit. We don't work that way. What it isA full boiler installation covers system design, boiler selection, safe removal of the old unit, upgraded pipework and controls where needed, a proper commissioning test, and manufacturer registration. It is not a like-for-like swap unless the swap is genuinely the right answer. Who it's forHomeowners and landlords in Woolwich, Greenwich, Blackheath, Eltham and across SE London whose boiler is over 10 years old, losing pressure, cycling on and off, running noisily, or costing more to run every winter. Also anyone converting from a conventional system to a combi. When you need itWhen repair costs approach 40% of a replacement, when parts for your model are discontinued, when your energy bills climb without a lifestyle change, or when you're extending the property and the current output is no longer sufficient. Why a professional mattersBoiler installation is notifiable work under Gas Safety (Installation and Use) Regulations 1998. Only a Gas Safe registered engineer can legally install and commission a gas boiler in the UK. Get it wrong and you invalidate the warranty, void your home insurance, and, in the worst case, put your family at risk of carbon monoxide poisoning. What’s at stake ## What happens when a boiler install is done cheaply The cost of a bad installation isn't in the invoice, it's in the ten years that follow it. ### Undersized boiler, cold showers Fit a 24kW combi in a three-bathroom house and you'll never get hot water on demand. The boiler cycles, kettling starts, and the heat exchanger fails inside 5 years. ### Skipped system flush Legacy sludge from your old system dumped into a brand-new heat exchanger blocks the primary circuit and voids the manufacturer warranty, you'll pay full price to fix a fault they should have covered. ### Non-compliant flue routing Flue terminations too close to windows, boundaries or openings breach Building Regulations Part J and produce a fail on any future landlord CP12 or homebuyer survey. ### No commissioning certificate Without a Benchmark log and Gas Safe notification, the boiler warranty is invalid from day one. When it breaks in year three, you're on your own. Common mistakes we fix - Choosing the cheapest quote without asking what's included - Believing a 24kW combi can run two bathrooms - Skipping the powerflush to save £400, and losing £2,400 in warranty cover - Accepting a like-for-like swap instead of a heat-loss calculation - Not registering the boiler with the manufacturer within 30 days Our process ## From your first call to the completion certificate. - 1 ### Free home survey Danny visits, measures hot water demand, checks radiators, gas supply and flue routes, and quotes in writing, no obligation. - 2 ### Boiler specification We recommend the right output for your home from Vaillant, Baxi, Ideal or Glow-worm, with a clear reason, not a commission. - 3 ### System preparation Powerflush or chemical flush as required, magnetic filter fitted, inhibitor dosed. Gas supply and flue upgraded to comply with current regs. - 4 ### Installation & commissioning Old boiler removed and disposed of safely, new unit fitted and commissioned to Benchmark standard, controls paired. - 5 ### Handover & warranty You get the Benchmark log, Gas Safe notification, manufacturer warranty registered in your name. Benefits ## What you actually get for the money. ### Lower running costs A modern A-rated condensing boiler runs 20–30% more efficiently than a 15-year-old unit, measurable savings from month one. ### Warranty up to 10 years Correct installation unlocks the full manufacturer warranty; Vaillant will honour up to 10 years when fitted by an accredited installer. ### Quieter home Modern modulating burners run at a fraction of the noise of older on/off boilers, no more thumping airing cupboards at 6am. ### Better hot water Properly sized combis or system boilers deliver consistent flow to multiple outlets simultaneously. ### Safer household New units include enhanced flue integrity checks and modern flame-failure protection, a step-change on anything pre-2018. ### Future-proof controls OpenTherm-compatible, smart-thermostat ready, and set up for weather compensation if you want it. Technical detail ## How we specify and install a boiler properly Most of the value you'll get from a new boiler is decided before we lift a spanner. This is what actually goes into a good install, and what most 'one-day swaps' skip. ### Combi, system or regular, matched to your home A combi suits flats and homes with one bathroom and a mains flow above 15 l/min. A system boiler with an unvented cylinder is the right answer for two-plus bathrooms or households that run multiple hot outlets at once. Regular (heat-only) boilers stay right where you have a large hot-water demand and a working feed-and-expansion loft tank. We size on real heat loss and real flow rate, not a table on the merchant's wall. ### Manufacturers we install Vaillant (ecoTEC plus, ecoFIT pure), Baxi (800 Combi, Duo-tec), Ideal (Logic Max, Vogue Max) and Glow-worm (Energy, Ultimate3). We're accredited to register the full manufacturer warranty on each, and we hold parts relationships across all five so servicing stays affordable for the life of the boiler. ### System protection and flushing Every new boiler goes onto either a full powerflush (sludge-heavy systems, particularly older Greenwich Victorian terraces with steel radiators) or a chemical flush and MagnaClean-style filter for cleaner systems. Sentinel X100 inhibitor is dosed on completion. This is non-negotiable, manufacturers routinely reject warranty claims where no flush has been recorded. ### Gas supply, flueing and Building Regs We check the existing gas supply diameter is sufficient for the new appliance (many older SE London installs run on 15mm and starve modern boilers). Flues are terminated to the current Part J minimum distances from windows, openings, boundaries and opposite walls. Where a horizontal flue passes through a void, an inspection hatch is fitted per BS 5440. ### Controls, zoning and smart heating We install and pair OpenTherm-compatible programmable thermostats (Vaillant vSMART, Hive, Nest, Tado) as standard. Boiler Plus compliance is delivered via load compensation, weather compensation, smart controls or FGHR, chosen to suit your home rather than a template. ### Landlord and HMO installations For letting properties in Woolwich, Plumstead and Thamesmead we deliver installations bundled with the annual CP12 landlord safety certificate and a service plan, so the property comes back on the market compliant and rentable inside the same visit. Recent work ## Photos from real jobs, not stock imagery. See the full gallery → Frequently asked ## Questions we hear every week. How much does a new boiler cost in Woolwich or Greenwich?+A straightforward combi swap in a two-bedroom flat typically runs £2,200–£2,800 fully fitted. A system boiler with unvented cylinder in a family home is usually £3,800–£5,500. Every job gets a free fixed quote in writing, no hidden extras. How long does a boiler installation take?+A like-for-like combi swap is normally completed in one working day. A back-boiler to combi conversion or system change takes 2–3 days. We schedule the work so you're not without hot water overnight. What warranty do you offer?+You get the full manufacturer warranty, up to 10 years on Vaillant and Ideal when we install them, registered in your name before we leave site. Do I need a powerflush with my new boiler?+If your existing system has any sludge or discoloured water, yes, and most systems over 8 years old do. Skipping it is the single most common reason a new boiler warranty gets rejected. Which boiler brand do you recommend?+It depends on your home. For most SE London properties we'll recommend Vaillant or Ideal on reliability and warranty terms. For tighter budgets Ideal Logic Max is genuinely excellent. Danny will tell you the trade-offs face to face, no commission-led sales. Can you install a boiler in a flat?+Yes. We install regularly in flats across Woolwich, Greenwich, Thamesmead and Abbey Wood, including balcony flueing, freeholder liaison, and where required, an insurance-approved plate flue kit. Do you handle the Gas Safe and Building Control notification?+Yes, we notify Gas Safe within 30 days and register the work with Building Control at no extra cost. You receive the certificates for your records and any future sale of the property. Do you offer finance?+We don't sell finance in-house, but Danny will happily talk you through what the job actually costs and where you can save (or shouldn't), no sales pressure. Can you do an emergency boiler swap?+If your boiler is beyond repair mid-winter we can typically install a replacement within 48–72 hours, and we'll leave temporary heating with vulnerable customers wherever possible. Book boiler installs ## Ready to get boiler installs sorted properly? Speak to Danny directly. Free quote in writing, honest advice, and a fair fixed price. No sales pressure, we’ve been at this for over 30 years for a reason. Call 07956 994429 Call 020 8244 0912Request estimate - Gas Safe registered #180521 - 4.9★ from 159 Google reviews - Office 8am–9pm, 7 days a week - Based in Greenwich · covers all SE London Related services ## Often booked together. See all services → Service ### Boiler Repairs Learn more Service ### Power Flushing Learn more Service ### Central Heating Installation Learn more Service ### Landlord Gas Safety (CP12) Learn more Gas Safe registered plumbing, gas & heating engineers with 40 years of local experience across South East London. Gas Safe #180521 Company No. 06064438 Services - Boiler Installation - Boiler Repairs - Power Flushing - Gas Safety Engineer - Landlord Gas Safety (CP12) - Gas Fires & Cookers - Heating Engineer - Central Heating Installation Service Areas - Greenwich · Woolwich - Blackheath · Eltham - Thamesmead · Plumstead - Abbey Wood · Erith - Dartford · Bexley · Sidcup Contact - 07956 99442924/7 Emergency - 020 8244 0912Office landline - info@dhplumbing.co.uk - London - Office: 8am – 9pm, 7 days a week © 2026 DHP London Ltd. All rights reserved. AboutOur WorkReviewsContactPrivacyTerms Call nowGet a quote