Looking to install an unvented cylinder? Call 020 8882 2266 for immediate service in the London area.

City Gas Services is your local G3 qualified unvented cylinder installation specialist in London. We recommend and install Megaflo cylinders in particular, as well as other makes.
Our engineers have a combined team experience of almost 200 years and have installed thousands of unvented cylinders over the years.

Before installing an unvented cylinder in your home, there are a number of considerations that need to be made. We can go over these considerations with you and do not charge for the survey that is required before we install your unvented cylinder.

Considerations Before Installation

1. Where will the cylinder be fitted?

Unvented cylinders are heavy, with some weighing as much as one ton when filled with water. You will need to have a strong base for the cylinder to rest on.

2. Water Pressure

Unvented cylinders are connected directly to the cold water main.

The pressure is limited on the cylinder controls to 3bar. Your water pressure needs to be greater than 1.5 bar (preferably more than 2bar) to work correctly.

The water pressure will need to be tested at your property using a water pressure gauge; this is normally done on the outside tap.

3. Water Flow Rate

It is important to understand the relationship between pressure and flow.

Pressure difference is what causes flow to happen. In the case of an unvented cylinder, this would be the pumped water main’s pressure entering your property.

Once the pressure has been tested, the flow rate needs to be checked using a weir cup. Flow rate is important because this is effectively the amount of water that passes out of the taps.

In many properties, lead is still in use as the service pipe. Normally, these pipes weigh 7lb. The diameter of the pipe is the same as 15mm copper.

You will need to ideally upgrade the pipe to MDPE (blue plastic pipe) with a diameter of 25mm, at a minimum.

4. Pipework

Many pipes found in today’s homes require an unvented cylinder to operate correctly and safely.

The pressure relief and temperature relief pipes have to be taken away from the cylinder to the outside of the property.

Before installing an unvented cylinder, the above considerations and testing need to be thought out and completed.

City Gas Services will help you design, specify and install a new unvented cylinder.

Contact us at 020 8882 2266 or freephone on 0800 075 8181 to book a FREE survey and estimate today.

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