G3-qualified installation with mains-pressure hot water and free mains pressure test
An unvented cylinder transforms how hot water reaches every tap and shower in your home. Instead of relying on a gravity-fed tank in the loft, the cylinder connects directly to the mains, so the pressure and flow you get at the shower head match the pressure coming into the property. Households used to weak hot-water flow notice the difference immediately.
Before we quote, our engineers carry out a full mains pressure and flow test on your incoming supply. Most modern South-East London homes have plenty of capacity, but a small number of older Victorian terraces benefit from an additional pressure-boosting solution that we'll discuss openly. The test takes about 30 minutes and is included free with every survey.
Installation typically takes one to two days depending on the complexity of the pipework and whether we're stripping out a redundant cold-water tank and feed pipe from the loft. We remove all old tanks, debris, and packaging from site, dispose of them responsibly, and leave your home as clean as we found it. Price guide is £2,500 to £3,500 fully fitted.
Because unvented systems run at mains pressure, the safety requirements are stricter than for vented cylinders. Every Primeworks engineer fitting these systems holds the G3 Unvented Hot Water qualification, and every installation includes the expansion vessel, temperature-and-pressure relief valves, and discharge pipework required by Building Regulations. You get a registered installation notice for your records.
Sarah K.
Horia and the Primeworks team installed a new combi boiler at our Lewisham flat last month. They turned up on time, kept the place clean, and walked me through every option before we picked the boiler. Quote was fair, no hidden extras. Hot water finally feels like hot water.
Tom M.
Booked an annual service for our boiler in Greenwich. Same-day appointment, fully thorough job, and I got a free radiator check thrown in. The digital service record landed in my inbox the same afternoon. Will definitely use Primeworks again.
Emma L.
We upgraded our Dulwich house from a vented tank to an unvented cylinder. Horia ran a proper mains pressure test before quoting and stripped out the old loft tanks while he was at it. Showers are night-and-day better. Honest, tidy, and properly G3 qualified.
David R.
No heating on a Saturday morning, called Primeworks at 9 and they had an engineer here by lunchtime. Diagnosed a faulty diverter valve, had the part in the van, finished by tea. Honest pricing, no rip-off Saturday surcharge. Genuinely good people to have on speed dial.
We serve all of South-East London, including Lewisham, Greenwich, Blackheath, New Cross, Dulwich, Forest Hill, Lambeth, and Beckenham. If you're nearby and not sure whether your address is in range, call 07534 469 008 and we'll confirm before you book.
Primeworks is a family-owned business led by Horia Nick Vrabiescu, who has over ten years of hands-on experience in heating and plumbing engineering. We built the company on local trust in South-East London and Horia personally oversees every job.
Yes. Every Primeworks engineer working on a gas appliance is Gas Safe registered, and our unvented-cylinder engineers also hold the G3 Unvented Hot Water qualification. Every engineer carries an ID card you can ask to see on arrival.
We operate seven days a week. Standard hours are Monday to Friday 08:00 to 21:00, and Saturday to Sunday 08:00 to 18:00. For genuine no-heat or no-hot-water emergencies, we treat the job as a priority repair within those hours.
Yes. Every quote we give is free and no-obligation. We come out, survey the work, and send you a clear written price with no hidden extras. For boiler installations and unvented cylinders we'll do the mains pressure / system flow check at the same visit.
We accept bank transfer, all major credit and debit cards, and cash. Payment is taken on completion. For larger boiler installations or unvented cylinder projects we're happy to discuss staged payments so you can plan around the work.
Generally, if your boiler is over 10 to 15 years old, frequently breaks down, or your energy bills are rising, a replacement is more cost-effective. During a site visit, we assess the repair-versus-replace value to ensure you aren't pouring money into an inefficient system.
A straightforward like-for-like swap usually takes one day. If we are converting your system (such as moving from a traditional boiler to a modern combi boiler) it typically takes two to three days to account for pipework upgrades and tank removal.
We treat your home with total respect. Our engineers use protective floor coverings and dust sheets in all work areas. Once the installation is complete, we remove your old boiler and any debris, leaving your home as clean as we found it.
Yes, all our installations include a free system flush and inhibitor treatment. This process removes sludge and debris from your radiators and pipes, which is required to keep your manufacturer's warranty active and ensures maximum system efficiency.
We work with leading manufacturers to provide comprehensive warranties, typically ranging from 5 to 10 years depending on the model. As accredited installers, we can often offer extended warranties that are not available to the general public.
You should have your boiler serviced every 12 months. This is necessary to keep the manufacturer's warranty active, maximise the boiler's efficiency and ensure safe, reliable operation.
Yes. If your system has failed completely, we prioritise your call as a priority repair. Before calling us, we recommend checking your prepaid meter (if applicable), ensuring your thermostat has fresh batteries, and checking if your boiler is displaying a specific fault code.
Our comprehensive service includes a visual inspection for leaks and corrosion, a flue gas analysis to check for carbon monoxide, a check of internal components and gas pressure, and a clean of the main heat exchanger if required. We provide a digital service record on completion, and a FREE radiator check is included with every boiler service.
Annual servicing typically runs between £100 and £300. Repair quotes depend on what's failed and which parts are needed, and we'll give you a fixed price after diagnosing the fault. There's no hidden call-out fee rolled into the bill afterwards.
Yes. We carry out annual CP12 inspections for landlords and managed portfolios across South-East London. We test every gas appliance, check for leaks, and issue the certificate on the same visit wherever possible. We can set up renewal reminders so you never miss the date.
Yes. Our engineers regularly work on Worcester Bosch, Vaillant, Ideal, Baxi, Glow-worm, and most other major brands. We carry common spares in the van, and when a manufacturer-specific part is required we'll order it the same day and book the return visit straight away.
Unlike a traditional gravity-fed system, an unvented cylinder is connected directly to your mains water supply. This means you don't need a cold water tank in the loft, and your hot water is delivered at mains pressure, providing much stronger flow rates for showers and taps throughout the home.
Most modern homes are suitable, but it depends on your incoming mains water pressure and flow rate. We conduct a mains pressure test during our initial survey to ensure your supply is strong enough to deliver the performance benefits an unvented system offers.
The installation of an unvented cylinder typically takes between one and two days, depending on the complexity of the pipework and whether we are removing old water tanks from your loft. As part of our service, we also remove all rubbish, any old water tanks from your loft and any debris from the old cylinder, leaving your home clean and tidy.
Yes, they are extremely safe when installed correctly. They are fitted with multiple safety features, including expansion vessels and temperature/pressure relief valves. Because of these high-pressure safety requirements, they must only be installed by a qualified engineer with a G3 Unvented Hot Water qualification.
One of the biggest benefits is that you can remove the bulky water tanks from your loft, freeing up storage space. The cylinder itself is usually housed in an airing cupboard or utility room. We will ensure the chosen location provides enough clearance for the pipework and future maintenance.