Schematic Unvented Heating System

This first is a combi boiler system where the boiler directly heats the water on demand.

Schematic unvented heating system. The diagram below shows the general layout of an unvented hot water system. Modern heating systems run by gas boilers tend to be unvented or pressurised. Before we look at the more technical aspects of the megaflo unvented boiler system which some incorrectly call the megaflow system or megaflow boiler instead let s take a look at the basics. For an entirely new installation s plan would be a far better choice as that does not have the default open problem and also allows the use of multiple zones for the central heating.

This simply means the time the boiler starts up and for how long how much heat it provides for either space heating or for domestic hot water or both. An automatic bypass valve is fitted inside most combi boilers by the manufacturer these days. This is a system from the people over at heatrae sadia a highly recognisable and trustworthy name in the industry. The electric versions use a coiled heating element to heat the water rapidly in a.

Unvented hot water systems. This diagram illustrates how simple the heating system connected to a combi boiler is. Regardless of the central heating design the sundial plan is a system that controls the boilers operating periods and temperatures for space heating and or hot water. One givaway is that there is often a pressure gauge on the boiler measured in bar.

Megaflo or megaflow system. The arrangement shown here is most likely for an existing y plan system where the cylinder is being changed to an unvented one. No external pump no tanks no external expansion vessel no motorised valves and in many cases item 6 is not needed either. Over pressurisation can be caused by a failed pressure reducing valve while overheating can occur if an unvented cylinder overheats and the water continues to increase in temperature and.

Visit the unvented cylinder page on our interactive house for comprehensive information on unvented hot water systems. In an unvented system there is no header tank and the water in the pipes is under pressure. A guide to the most common types of domestic heating and hot water systems with diagrams including indirect boiler system unvented system thermal store. Unvented systems have two basic dangers that must be addressed.

A guide to the different ways of heating domestic hot water so you can identify problems and faults with the hot water tank or central heating system and carry out any maintenance needed. These are over pressurisation and overheating. There are three types of domestic hot water system.