Unvented cylinder installation in London

Define what the new installation must deliver

Begin with the outlets and the way they will be used. A second bathroom, consecutive showers or a change from a commercial unit to residential use can alter demand. Describe which outlets must work simultaneously and the acceptable recovery period, rather than choosing a cylinder solely from the number of bedrooms.

Also explain why unvented storage is being considered. It may be a planned new system rather than a response to a failure. If the objective is stronger shower performance, the survey needs to assess supply and distribution; a pressurised cylinder cannot create an unlimited incoming water supply.

Check mains supply and the distribution layout

The assessment should consider available flow and pressure in realistic conditions, the incoming pipework and the proposed connections. A static reading alone does not describe what happens when several outlets operate. Existing restrictions or shared building supplies can affect whether the proposed performance is achievable.

Tell us whether the building has communal plant, shared rising mains or restrictions on alterations. Access to relevant supply points may require the managing agent. If additional supply work is necessary, it should be explained as part of the project rather than discovered only after the cylinder has been delivered.

Choose the heating arrangement before ordering

An indirect cylinder receives heat from another source through a coil or other specified heat-exchange arrangement; a direct cylinder uses immersion heating. The appropriate selection depends on the current heat source and any planned changes. An ordinary combi installation does not automatically need a cylinder added to it.

If a future heat pump or solar installation is part of the brief, state that now. Compatibility depends on the selected model and design, not simply a spare connection. Ask the installer to identify what is included today and what additional equipment or changes would be needed for that future stage.

Plan the location and discharge route together

The cylinder location has to work for maintenance, connections and a compliant discharge arrangement, as well as floor area. A convenient cupboard may be unsuitable if the required route cannot be achieved. A different position can alter hot water pipe runs and the amount of building work.

Unvented systems rely on appropriate pressure and temperature protection. Approved Document G provides the hot water safety framework in England. The installer should explain the applicable building-control process and documentation. Do not accept a proposal that treats the discharge pipe as an optional finishing detail or conceals the need for access.

Understand conversion work beyond the cylinder

Converting a vented arrangement can involve changes to supply and distribution pipes, controls and redundant storage connections. The new proposal should make clear which existing equipment stays, which is removed and how the remaining installation is left. An unvented system is not created by closing off the vent on an existing tank.

Where the project accompanies a bathroom refurbishment, coordinate the plumbing design before finishes close off routes. Ask who handles electrical work, access openings and reinstatement. Clear responsibilities help avoid a completed bathroom that must be reopened because the cylinder connections or safety route were never resolved.

What a useful survey and proposal contain

Provide plans if available and identify any fixed deadlines for other trades. The proposal should specify the cylinder and capacity, relevant controls, supply work, discharge provision, electrical connections, commissioning and removal or making-good scope. It should also state dependencies that still need confirmation.

• Household or premises demand and simultaneous outlet use.
• Existing supply, heat source and proposed cylinder location.
• Access dimensions and room for ongoing maintenance.
• Necessary permissions, isolation arrangements and working hours.
• Documentation, product terms and ongoing service requirements.

Installation competence and handover

Ask who will undertake the unvented work and how their relevant competence will be established. G3 training and competence are important for this work; Gas Safe registration concerns gas tasks and is not a substitute for unvented competence. Electrical connections also require appropriate competence and assessment.

At handover, obtain the applicable records and an explanation of ordinary user controls, maintenance and what to do if discharge appears. Do not experiment with relief valves or thermal safety controls. The system should remain serviceable after cupboard fittings and other finishing work are complete.

Request an installation survey

Loyal Plumbers operates with 10 active vans and 24/7 coverage across London and inside the M25. For a planned installation, send the postcode, current system, proposed use and any drawings or access constraints you can describe. We establish the survey and project scope before an installation commitment.

Use the form for written details first. It does not accept image uploads; the team can request useful photographs by email after your enquiry. Take photographs only where access is safe.