An old unvented cylinder leaking through the ceiling below, a fixed quote, and a new 150-litre stainless cylinder installed by G3-qualified engineers with the pipework insulated.
The unvented cylinder in a Wolverhampton home sat on the third floor, and it had started leaking. By the time we were called the water had come through and damaged the ceiling below. We surveyed the cylinder and the cupboard, and quoted for a replacement rather than a patch, because a leaking unvented cylinder is not a part you repair. The customer accepted the quote. We removed the old cylinder, fitted a new 150-litre stainless steel unvented cylinder to current standards with its safety controls, expansion vessel and discharge pipework, and insulated all the pipework. Unvented cylinders can only be installed by a G3-qualified engineer, and ours are.
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Unvented cylinder repairs £99 for the first hour in office hours, parts quoted first. Immersion heater and vented cylinder repairs are quoted after a £99 diagnosis. Unvented cylinder annual service £120 (£90 with a boiler service).
No travel charge within 10 miles of B20 2JS. Further out, £2 per mile may apply — always agreed before anything is booked. Full price list
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The customer's hot water cylinder lived in a cupboard on the third floor, which is the worst place for a cylinder to start leaking. This one had, and the water had already come through and damaged the ceiling of the room below by the time they rang us.
The cylinder was an unvented one: a mains-pressure cylinder with no cold tank in the loft, heated by the boiler through a coil. When the steel body of one of these starts leaking there is no repair worth making. It is a pressure vessel, and once it has failed it has failed. We surveyed the cylinder, the cupboard, the discharge arrangements and the pipework, and gave the customer a fixed quote for a replacement to current standards. They accepted it.
We drained and removed the old cylinder and fitted a new 150-litre stainless steel unvented cylinder in its place. That means new pipework in copper, the safety controls that an unvented cylinder must have, the expansion vessel, and the tundish and discharge pipework that carry water away safely if a safety valve ever opens. Once the cylinder was commissioned and checked we insulated all the pipework, which keeps the heat in the hot water where it belongs and stops the pipes sweating in the cupboard.
The customer got their hot water back, a cylinder that will not be coming through the ceiling, and an installation that meets the current standards rather than the ones in force when the old one went in.
An unvented cylinder holds mains-pressure water heated to sixty degrees or more. If the safety controls are wrong or missing, the failure is not a drip but a rupture. That is why the Building Regulations require anyone installing, commissioning or servicing an unvented cylinder to hold a G3 qualification, and why the work has to be notified. Our engineers are G3 qualified. Whoever you use for a cylinder, ask to see the card before they start, and ask for the notification when they finish.
A replacement unvented cylinder is quoted after a survey, because the size of the cylinder, the state of the pipework and the discharge route all change the job. The quote is fixed once it is given. An annual unvented cylinder service is £120, or £90 when bundled with a boiler service on the same visit, and it is the service that catches a failing cylinder before the ceiling does. Details are on our unvented cylinders page. Faults that can be repaired without replacing the cylinder are on our hot water cylinder repairs page.
A leak from a fitting, a valve or a joint can often be repaired. A leak from the body of the cylinder cannot. The cylinder is a pressure vessel, and once the steel has failed the only safe answer is a replacement. On this job the cylinder itself was leaking, so we quoted to replace it.
G3 is the qualification the Building Regulations require for anyone who installs, commissions or services an unvented hot water cylinder. Unvented cylinders run at mains pressure and high temperature, and the safety controls have to be right. Work by an unqualified person is illegal, will not be notified, and can void your home insurance. Our engineers are G3 qualified.
Usually a day. Draining and removing the old cylinder, fitting the new one with its controls, expansion vessel and discharge pipework, commissioning it and insulating the pipework is a full day's work for a two-person team on a straightforward swap. Awkward access, a third-floor cupboard like this one, or pipework that needs rerouting can add to it, and we say so in the quote.
Yes. Wolverhampton, Tettenhall, Penn, Wednesfield and Willenhall are all within our range from Handsworth Wood, and cylinder and boiler installations are quoted at the same fixed prices as anywhere else we work.
Job attended and photographed by our engineers in Wolverhampton, April 2026. Written up by Saeed Iqbal, the engineer who leads Synergy Gas & Plumbing (Gas Safe registered 594385). More recent jobs in the area are on our Wolverhampton page, and every job we write up is on the case studies index.
Service £120
Annual service £120 (£90 with a boiler service). Repairs £99 for the first hour in office hours, parts quoted first.
No travel charge within 10 miles of B20 2JS. Further out, £2 per mile may apply — always agreed before anything is booked.
Heat exchanger stripped and cleaned on a Viessmann that is showing its age, then the Tempest cylinder serviced on the same visit. Customer given a straight view on when to start planning a replacement boiler.
Read the case studyA London landlord booked online for a tenant with no hot water from an Intatec Hiper HIU. The pressure independent control valve was sticking and the strainer behind it was seized and packed with dirt. Freed, stripped, cleaned and refitted; a new valve booked for a return visit.
Read the case studyThe main heat exchanger had failed on a boiler that had done 17 years, so the numbers pointed one way. Like-for-like swap into the same cupboard, Worcester magnetic filter fitted, system dosed, guarantee registered.
Read the case studySurvey and fixed quote for replacement, £120 for the annual service. Call or WhatsApp a photo.
