Ideally, the mains water pressure at peak times should be a minimum of 1.5 bar dynamic pressure, although all unvented systems will operate at pressures as low as 1 bar dynamic pressure. The size of the incoming main ideally needs to be at least 25mm MDPE or 22mm copper, in order to provide adequate flow. Megaflo Unvented will check and assess these parameters as part of our free on-site survey. For properties with multiple bathrooms, a higher flow rate would be required to meet the required demand.
Where the mains water supply is not suitable, then Water Boosting may be required.
All unvented hot water systems should have a tundish fitted. This provides an air-gap in the discharge pipe and also enables any discharge from the safety devices to be seen, as it runs through the pipe. The required installation and positioning of the Tundish is controlled and documented in the Building Regulation G3 Approved Documents.
Unvented systems require sufficient incoming pressure and flow to be able to service all outlets within a property. If there is insufficient flow, then an accumulator may offer a suitable solution. An accumulator is a vessel that stores water under pressure and is typically installed on the incoming mains supply to provide a buffer store of pressurised water. This offers a simple and effective solution to address flow rate issues found in properties with multiple bathrooms.
The Megaflo cylinder is designed with an internal air bubble, to absorb the expansion as the water is heated. Other brands of unvented cylinders may use an external expansion vessel to provide the same function. This is also mentioned above in What is the expansion vessel for?
Over time the Megaflo air bubble may be absorbed into the water, in which case the air bubble will need replenishing. This is done as part of the annual service, but any competent person can reinstate the air bubble by following the instructions on the side of the cylinder. If in any doubt, please refer to a G3 qualified engineer.
Why Choose Us
At Megaflo Unvented, we do what we say we’ll do. Our integrity and competence values demand this. We are accountable for our words and actions, and that we deliver a service that meets or exceeds all expectations of quality and timeliness.
Customer service is our highest priority and to reinforce this, we adhere to the following guidelines: