Cylinders · G3 certified · Hertfordshire
Mains-pressure hot water to every tap, sized for your actual demand, installed, certified and commissioned by G3-qualified engineers.
G3 certificate issued on completion · Megaflo, Telford & Heatrae Sadia · 25-year cylinder warranty options
Service overview
Plain-English breakdown, so you know exactly what you're paying for, and why it matters before we set foot on site.
Supply, install, swap and service vented (open-vent) and unvented (mains-pressure) hot water cylinders across St Albans and Hertfordshire. Includes pipework, expansion vessel, tundish, discharge route, immersion wiring and G3 commissioning paperwork.
Homeowners with weak hot water pressure upstairs, anyone converting from a combi to a system boiler, families adding a second bathroom, and properties replacing a 25-year-old vented cylinder.
Survey within the week. Full cylinder swap is typically a one-day job; combi-to-system conversion is 2–3 days.
An unvented cylinder is a pressurised vessel under serious mains pressure, it must be installed by a G3-qualified engineer and certified, or building control and your home insurance won't recognise it.
The cost of doing nothing
Most cylinder failures we replace are caused by a missed annual service, specifically a knackered expansion vessel that's been hammering the cylinder wall for years.
Our process
Same system every time. No improvising on your floor.
We count bathrooms, basins, simultaneous draws and household size. Cylinder size is matched to demand, not to whatever fits.
Cylinder, all controls, pipework, discharge route and commissioning, in writing.
Old unit drained and removed, new cylinder fitted, expansion vessel charged, PRV tested, tundish run to safe discharge.
Benchmark book filled in, G3 certificate issued, cylinder registered for warranty, controls demoed.
What you get
Strong, even hot water, no more 'pencil-thin' shower upstairs while the kitchen tap runs.
Two showers and a kitchen tap simultaneously, sized properly, the cylinder copes.
Combi-to-system or vented-to-unvented removes the cold tank and F&E tank from the loft, clean, dry, usable space.
We size and configure for future solar thermal or heat pump tie-ins where you're planning ahead.
Up to 25 years on the cylinder body (Megaflo, Telford Tempest) with annual service.
G3 certificate + Benchmark + warranty registration done on the day, not 'we'll email it later'.
In depth
The details a salesperson skips. Skim it, or read every word, both are useful.
Vented (open-vent) cylinders rely on a cold water tank in the loft for pressure. Cheap and simple, but pressure upstairs is always weak. Unvented cylinders run directly off the mains, pressure is the same at every tap on every floor. Unvented is the right answer for nearly every modern home with reasonable incoming mains pressure (2+ bar). Where mains is poor, we'll quote a thermal store or a mains booster pump as the honest alternative.
Under-sizing is the single most common cylinder mistake. Rule of thumb: 1 bath = ~100L of hot, 1 shower = ~50L, two-bath house = 200–250L minimum, three-bath family = 250–300L. We size for peak simultaneous draw, not for 'one tap at a time'. Going one size up costs ~£150 in cylinder cost and saves a decade of cold-shower complaints.
Unvented cylinders are pressurised vessels. Building Regulations Part G3 makes it illegal to install one without a G3 qualification, and home insurers void claims on unrecorded installs. We're G3 certified, every install is registered with the local authority where required, and you get the certificate in your hand on the day.
G3 servicing is a separate annual check from your boiler service. It covers expansion vessel charge pressure test, PRV (pressure relief valve) test, T&P (temperature & pressure) valve test, immersion check, anode inspection on older units, and a flow/temperature performance test. Most cylinder failures are preventable with this annual check. Available standalone or bundled with your boiler service contract.
Heatrae Sadia Megaflo (industry standard, widest range, 25-year warranty), Telford Tempest (best stainless build, strong on bespoke sizes), Gledhill Stainlesslite (good value, solid 25-year). We don't fit budget no-brand cylinders, the saving is real on day one and gone within 5 years.
General work gallery
A broader look at recent installs, hot water systems, testing work and finished jobs across domestic and commercial sites.
Commercial heating
Installed and commissioned by Heatrite.
Commercial heating
Installed and commissioned by Heatrite.
Boiler installation
Installed and commissioned by Heatrite.
Oil heating
Installed and commissioned by Heatrite.
Unvented cylinders
Installed and commissioned by Heatrite.
Hot water systems
Installed and commissioned by Heatrite.
Boiler installation
Installed and commissioned by Heatrite.
Gas testing
Installed and commissioned by Heatrite.
Bathroom installation
Installed and commissioned by Heatrite.
Unvented cylinders
Installed and commissioned by Heatrite.
Bathroom installation
Installed and commissioned by Heatrite.
Boiler installation
Installed and commissioned by Heatrite.
Commercial heating
Installed and commissioned by Heatrite.
Boiler installation
Installed and commissioned by Heatrite.
Commercial heating
Installed and commissioned by Heatrite.
Boiler installation
Installed and commissioned by Heatrite.
Hot water systems
Installed and commissioned by Heatrite.
Hot water systems
Installed and commissioned by Heatrite.
Oil heating
Installed and commissioned by Heatrite.
Unvented cylinders
Installed and commissioned by Heatrite.
Boiler installation
Installed and commissioned by Heatrite.
Unvented cylinders
Installed and commissioned by Heatrite.
Commercial heating
Installed and commissioned by Heatrite.
Commercial heating
Installed and commissioned by Heatrite.
Hot water systems
Installed and commissioned by Heatrite.
Commercial heating
Installed and commissioned by Heatrite.
Frequently asked
Can't see your question? Call 07584 076105 or 07702 523464.
Yes, and it's often the right answer for 3+ bathroom homes. We'll quote the whole job: new system boiler, sized unvented cylinder, all controls, removal of the redundant combi and a tidy install. Typically 2–3 days on site.
Payment & finance
Boilers, bathrooms and larger installs can be spread over time with Klarna or Clearpay finance, just ask when you book.
We carry a card machine in the van, tap, chip & PIN or contactless on completion.
Spread the cost of your boiler or bathroom install with flexible Klarna finance options.
Pay over time with Clearpay, ideal for boilers, cylinders and full bathroom fits.
Ready when you are
Written fixed quote. Gas Safe engineer. No upsell, no pressure.
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