JAB Expansion Kit Expansion Vessel, Check Valve

The kit comprises of:

• 2L Expansion Vessel and
• Check Valve

This kit is required if either of the following conditions applies:

1. Presence of device preventing reverse flow
If a one-way device is fitted that prevents hot water expansion, the pressure relief valve would operate routinely on the heating cycle. This is not permissible under Water Regulations. Note that pressure reducing valves, water meters and similar devices are usually one-way and would block expansion.

2. Cold water off-take too close to the heater
It is a requirement to ensure that stored heated water does not mix with drinking water supplies. If there is a cold water off-take very close to the heater there is a risk that the hot and cold water supplies would mix. The minimum distance required between the heater and the nearest cold water off-take is 2.8m for the 10L and 4.2m for the 15L model.