Admittance Valve (air)

An air admittance valve can be compared in its operation to a rather large non-return type of valve, where the air is allowed to enter into your system through the valve but does not allow foul smelling air escape into the atmosphere around your WC. It is an efficient alternative valve that takes the place of your original siphon type that is probably fitted to your system. So if a negative pressure is in the drain of the system, the valve will open rather than the trap water being dragged out. The air admittance valve can be fitted by NW4 Plumbers . Air admittance valves can be found in a varied range of sizes and sometimes the main waste drainage stack can be fitted with the air admittance valve.
These valves are generally used when two soil stacks exist in the same building, or where there are a number of buildings that close to each other, the valve makes it unnecessary to route the highest point of the soil discharge stack out through the roof. This will mean there would be no real need for any extra work like tiling for example and protects the building from rainwater ingress. The air admittance valve is best to be installed above the critical level for any spillages of an appliance. If the valve is not fitted in that location and a blockage occurs it would back up and cause the valve to lose its water tight integrity. An NW4 Plumber is familiar with this system. As long as the valve is well insulated it can be fitted in exposed locations like loft spaces, as condensation in the pipework can freeze.



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