Lochinvar LBF121, Installation, Commissioning & Maintenance Instructions

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11.0 WATER CONNECTIONS
11.1 GENERAL
Water connection locations are shown in Section 2.1: DIMENSIONAL DRAWINGS . The size of the water
connections are given in Table 3.1.
The maximum length of hot water draw-off dead legs, when a secondary return is not fitted shall be in accordance
with
CP342 .
All circulating/distribution pipework should be covered with suitable insulation.
Ideally, individual valves should be fitted to each unit to enable isolation from the system. The arrangement must
be in accordance with the requirements of
BS6700 .
11.1.1 SYSTEM DE-STRATIFICATION
In a vessel containing water at different temperatures the hotter water will tend to accumulate at the top with
progressively cooler water further down; this layering effect is called stratification. The design of storage water
heaters allows heat transfer throughout the volume of water and therefore the stratification effect can lead to
overheating in the hotter areas at the top of the vessel. Where cooler pockets occur in the stored volume, there is
also a risk of the incubation of Legionella and other waterborne bacteria.
A de-stratification pump kit is available from Lochinvar Limited as an ancillary option. The de-stratification kit
works by using a pump to circulate water from the top of the vessel to the bottom of the vessel. This action
ensures that the water held in the unit is maintained at a consistent temperature throughout. By achieving a
uniformed stored water temperature of at least 60°C, the risk of any bacterial contamination is virtually eliminated.
Systems that have a building loop incorporated onto the vessel may not require a de-stratification kit, as the
circulation around the building from the top of the vessel back to the bottom should provide sufficient mixing.
Lochinvar has developed this kit to meet the stringent recommendations of both the HSE Approved Code of
Practice L8 and Department of Health memorandum HTM 04-01 relating to the control of Legionella. For full
compliance, a timer should be used to operate the pump for a period of at least 1 hour each day.
Where the pump is used to prevent overheating, it should run throughout the operational period of the water
heater.
11.2 OPEN VENTED SYSTEM ARRANGEMENT
The Lochinvar LBF range can be used in an open vented arrangement provided that a vent pipe in accordance
with CP 342 , or BS6700 as appropriate is fitted. For typical installation schematic drawings, refer to Figure 10.1 &
Figure 10.2 .
11.3 UNVENTED SYSTEM ARRANGEMENT
NOTE: IT IS STRONGLY RECOMMENDED THAT UNVENTED HOT WATER SYSTEMS BE INSTALLED
BY AN APPROVED INSTALLER.
If the Lochinvar LBF range is to be used in an unvented arrangement, the system should follow the guidance given
in
BS6700 and must comply with The Building Regulations 2000: Part G3 . A kit of components that have been
suitably sized for the unvented operation of the appliance is available from Lochinvar Limited. For typical
installation schematic drawings, refer to Figure 10.3 & Figure 10.4 .