Technical data

25
STRATA1
17.0 hydraulic system
design
OS
C
AAV
W
ST
IV
IV
SV
DOC
IV
IV
DOC
LSVDOC
Divertor Valve
Strata 1 Boiler
Condense
Waste
Expansion
Vessel
Calorifier/Indirect Hot Water Cylinder
Filling Point
CWM
DOC
Strainer
Heating Load
PS
IV
IV
OS= Outside air temperature sensor, used where
direct-on-boiler weather compensated flow
temperatures are required
C= Room temperature controls
e.g. RE2132 modulating room unit from
MHS Boilers, or, separate time clock &
room thermostat
S= HWS sensor from MHS Boilers. Gives 24Hr
HWS operation
W/T= Alternative to "S" where "W" is a time
switch in series with a cylinder thermostat
"T". Allows for timed HWS.
Divertor valve will require SPDT relay if not
spring return.
Divertor valve must be so installed as to
spring return to heating.
PS= Low water pressure cut off switch.
Typical single Strata 1 boiler installation serving domestic hot
water and heating where hotwater has priority via a divertor
valve. The in-built circulating pumps within the boiler are used to
circulate the system (used only where system index resistance
< pump residual head - see page 23). Flow temperature to
hotwater is constant and flow temperature to heating may be
constant or weather variable.
System Type 2