Table 1 Conditions of use for Type 2 valves
7
MODULATING COMBI BOILER
This thermostatic shower valve is designed for use with modulating
combination boilers.
When installing on a modulating combination boiler it is sometimes
possible for the interaction of a thermostatic valve with the combi to
cause the boiler to cut out and cut in again, with the result that the
water will become alternatively cold and hot. To overcome this, a 4 L/min
flow regulator should be fitted upstream of the thermostatic valve.
It should be fitted in any 15mm compression fitting in the dedicated cold supply pipe.
It is important to choose a compression fitting located in a position which is accessible after installation
and it must be fitted the correct way round for the direction of flow. The regulator can be fitted in either
the inlet or outlet side of the compression fitting. If fitting in an outlet side, ensure the o-ring is seated
fully in the visible rebate around the edge of the regulator. Use the tip of a small screwdriver or similar
to achieve this. Ensure the tail of the pipe is not fouling the regulator (shorten if required) and do up
the compression fitting as normal. In a minority of cases, where the boiler is of a type which stores a
small quantity of very hot water, it may also be necessary to fit a 4 l/min flow regulator in the hot supply.
flow direction
through
flow regulator
Isolation valves MUST be fitted to permit future maintenance of these products.
See sect 12 for more details.
Check valves are included with this product inside the inlets see sect 11.
These regulators (code A962570NU) can be obtained by contacting fastpart:
3 SUPPLY CONDITIONS
For more information on spare parts why not visit our spare website
www.fastpart-spares.co.uk
fast
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a
p
BSEN1111
Operating pressure range:
High Pressure
Maximum static pressure
10 bar
Flow pressure hot and cold
0.5 to 5.0 bar
Hot supply temperature
55 to 65 °C
Cold supply temperature
5 to 20 °C
Temperature differential characteristic (TDC)
10 °C
