Technical data

9
GEMINI HSC
10.0 unvented
hot water installation
To install a Gemini HSC Calorifier as an unvented hot water storage package, then a Water Regulations
Advisory Scheme approved kit of safety devices, valves and fittings complying with BS7206:1990 and
satisfying the requirements of Building Regulation G3, available from MHS Boilers Ltd must be installed to
protect the system and prevent water temperature from exceeding 100°C. The kit of parts includes as a
minimum (see checklist of components 10.2), a suitably sized expansion vessel with air charge pre-set at
3.5 bar, a pressure limiting valve set at 3.5 bar, an expansion relief valve set at 6.0 bar, a temperature and
pressure relief valve set at 7.0 bar and 90-95°C, a core manifold assembly with integral non return valve, a
tundish and a 2 port spring return motorised valve.
The components must be installed as shown in fig 4. There must be no valves installed between the
calorifier and the connection to the expansion relief valve. The connections provided for the connection
of the temperature and pressure relief valve and the expansion relief valve must not be used for any other
purpose. The mains water supply pressure must not exceed 12.0 bar.
10.1 unvented installation
component check list
calorifier models 60i, 100i, 150i
Component Part No.
1. 22mm pressure reducing valve with integral coaxial strainer and PRED 510 008
balanced cold water take off connection (blanked) Pre-set 3.5 bar.
2. 22mm expansion/check valve assembly with integral expansion vessel connection. CORE 215 002
Relief setting 6.0 bar.
3. 12 litre expansion vessel. Precharge pressure 3.5 bar. XVES 600 027
4. Expansion vessel mounting bracket c/w fixings. BRKT 240 023
5.
3
/
4
" aluminium braided connection hose (for expansion vessel) 1000mm long. HOSE 202 106
6.
3
/
4
" MI BSP Inlet/22mm relief connection temperature and pressure safety PTEM 575 901
relief valve with 230mm probe set 7.0 bar and 90-95°C.
7. 22mm x 28mm acetal tundish straight. TUND 219 001
8. 1" FI BSP equal tee bronze for temperature and pressure relief valve connection ZTEE 250 007
to hot water draw off connection.
9. 1" x
3
/
4
" BSP reducing bush DZR for temperature and pressure relief valve ZDAP 201 002
connection to tee piece (as listed above).
10. 1" x
3
/
4
" BSP reducing bush DZR for connection of tee piece (as listed in 8 above) ZDAP 201 002
to hot water draw off connection of model 60i calorifier.
Not required for models 100i, 150i and 200i.
11. 28mm Landis two port spring return motorised valve c/w actuator. ZONE 250 401