There are several different types of cylinders on the market and Transgas Services works on all types. Whether this be the repair of a faulty thermostat, recharging of an expansion vessel during a routing service of an unvented cylinder or fixing a leak Transgas Services will be able to assist.


Standard gravity fed cylinders

This is a very traditional cylinder that is installed in many homes across the UK. It is fed from the tank to the cylinder and pressures at the shower are traditionally poor unless boosted by some type of pump. The one shown in the first diagram is a direct cylinder as this is heated by an immersion heater. The second image is an indirect cylinder and is heated by another means, usually a boiler but can be via solar also. Transgas Services can replace faulty components on the cylinder, like the thermostat, or can replace the cylinder like for like or upgrade to a different type.


Unvented cylinders – (Megaflo as lots of people know them by)

Transgas services has the relevant qualifications and can install, service (recommended by the manufacturer’s every year) and repair all makes/models of unvented cylinders.

Unvented cylinders are mains pressure fed cylinders and offer good flow rates of water to several different outlets at the same time. This assumes the water main is up to the task. At Transgas Services we can come out with our flow cup and pressure reader and check your main is able to keep up with the demands of an unvented cylinder. If it is not we are able to offer alternatives to boost the pressure (Click link here)

Again unvented cylinders are either direct or indirect (electric or boiler/solar) but they do not have the storage tank in the loft. They also do away with noisy shower pumps so can offer an ideal solution if the shower pump is waking the whole family up when the first shower is being draw.

If coupled with a new boiler installation Transgas Services can offer up to 9 years guarantee on the cylinders and boilers components. Easy payment plans (finance) is also available on cylinders.


Not all plumbers can work on unvented cylinders as they are covered by a special G3 building regulations. At Transgas Services all our engineers are able to work on unvented cylinders. See how wrong it can go if you get someone who gets it wrong.