16
STRATA2
4.5 hydraulic system design
Important Note:
Strata 2 boilers must only be installed on sealed and pressurised systems. A sealed
system must only be filled by a competent person. Instructions for filling the system are supplied in
section 6.0. A low pressure cut off switch must be installed into the system.
All systems must be thoroughly cleansed prior to the connection of the boiler.
The system water should be treated to prevent general system corrosion and the
deposition of scale or sludge in the boiler waterways. Faliure to observe this
requirement will render all guarantees on the product void.
If installing the boiler onto an
old system, it is recommended to install a spirotech or similar dirt arrester/filter.
If plastic pipes are used for the flow and return lines, for radiators or underfloor heating, a plate
exchanger should be considered between the system water and the boiler water. If such a separator is not
used, the MHS guarantee on all boiler parts will become null and void, unless it can be proved that the
plastic pipes used have a vapour tight layer.
The connection of the flow and return are located at the top and the rear of the unit. With regards to
servicing, it is a requirement that isolation valves are installed.
For specialist advice and water treatment products, contact:
Betz Dearborn
Fernox, Britannica Works
Widnes, Cheshire WA8 8UD
Clavering, Essex CB11 4QZ
Tel: 0151 424 5351
Tel: 01799 550811
AAV
Outside Air
Temperature
Sensor
Room Unit
RE3231
Strata 2 - 120
Boiler
Condensate Waste
Low Pressure Switch
Exapnsion Vessel
Filling Point
CWM
DOC
DOC
LSV
IV
SV
IV
IV
Strainer
DOC
Return Sensor
Return from
Load Circuits
Temperature
Sensor (Boiler)
Low Velocity
Mixing Header
Max Velocity
0.5m/s
Flow to
Load Circuits
eg. Heating
Circuit
& HWS
Calorifier
To HWS Sensor
recommended system design
typical single Strata 2 - 120 boiler installation
Fig 4.5a