Hot water cylinders & storage systems in Macclesfield
If your house has a cylinder in an airing cupboard, your hot water comes from stored water rather than being heated on demand. That gives you much better flow to two bathrooms at once — and it gives you a component that will eventually need attention.
Two kinds exist and they are not interchangeable. A vented cylinder is fed by a tank in the loft and works on gravity, so pressure upstairs is modest. An unvented cylinder is fed straight off the mains and delivers full pressure to every outlet, which is why most upgrades go that way. Unvented installation and servicing are notifiable under Part G3 of the Building Regulations and require a separate qualification.
Stored hot water also carries a safety duty. It needs to sit at 60°C to keep legionella bacteria from establishing, while the water reaching a bath or basin tap should be limited so nobody is scalded. Those two requirements pull against each other, and blending valves are how they are reconciled.
Hot water & cylinders — every job, in detail.
8 jobs in this category. Each has its own page explaining what's involved, what your plumber checks and when it's worth calling someone out.
Unvented cylinder installation
An unvented cylinder is fed straight off the mains, so every tap and shower runs at mains pressure and the loft tanks disappear. Installation is notifiable under Part G3 of the Building Regulations and requires a G3-qualified installer — it is a pressure vessel, and the safety devices on it are not optional.
Read more →Unvented cylinder servicing
An unvented cylinder needs an annual service by a G3-qualified engineer: expansion vessel charge, relief valve operation, temperature controls and discharge arrangement. It is a pressure vessel with safety devices that only prove themselves when tested, and most warranties require the service to stay valid.
Read more →Vented cylinder replacement
A vented cylinder is the traditional copper tank fed by a cistern in the loft, working on gravity. Replacing one is a straightforward job, and it is the moment to decide whether to stay vented or upgrade to unvented — because the pipework changes are much cheaper done once.
Read more →Immersion heater replacement
An immersion heater is an electric element in the cylinder, used either as the main heat source or as backup when the boiler fails. Replacement means draining the cylinder, releasing an element that has often corroded into place, and fitting a new one with its thermostat set correctly.
Read more →No hot water diagnosis
Which parts of the house have no hot water, and whether the heating still works, narrows the fault immediately. Heating fine but no hot water on a combi points at the diverter valve; on a cylinder system it points at the zone valve, the cylinder thermostat or the coil.
Read more →Expansion vessel replacement
An expansion vessel absorbs the expansion of water as it heats. When its air charge is lost, pressure spikes on every heat-up and escapes through a relief valve — which looks exactly like a leak and is not one. Testing and recharging takes minutes; replacement is a short job.
Read more →Cold water storage tank replacement
The cold water cistern in the loft feeds the cylinder and, on older systems, the bathroom. Old galvanised or uncovered tanks should be replaced with a modern plastic cistern with a close-fitting lid, screened vent and overflow, insulated on the sides and lid but never underneath.
Read more →Legionella risk & water temperature checks
Legionella bacteria multiply in stored water between roughly 20°C and 45°C. The control is straightforward: keep hot water stored at 60°C and delivered above 50°C, keep cold water below 20°C, and remove dead legs where water sits stagnant. Landlords have a legal duty to assess and control the risk.
Read more →Not sure which one you need?
Describe it in your own words on the quote form. Your plumber will work out what the job actually is when they ring you back — usually the same day.
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