MS10-11C Issue 4d
17
Plumbing Advice
Alarms
It is not a requirement to fit an alarm on the system, but it is recommended. The alarm will
act as a warning to the customer if the SCWS should operate. The alarm should be fitted
to the SCWS discharge pipe and should register an increase in temperature when the
SCWS is in operation. The customer should be notified that if this SCWS system/alarm is
continually operating that measures should be taken to stop the overheating of the
appliance. Measures to take are as follows:
1) Close all the air controls, including the tertiary and thermostatic air controls
2) Run hot water tap to remove some of the hot water in the cylinder (if fitted)
The customers should also be made aware that if there is constant operating of the
SCWS, they should contact the installer to diagnose any problems with the system.
N.B. A boiler that is too large for the required heat load will trigger the SCWS too often and
should therefore be replaced by a boiler that is better suited to the heating load.
It is mandatory to fit the safety components below when running a
closed/pressurised system. Failure to install these components will void your
guarantee and warranty, and risk the possibility of damage, to the extent of the
boiler exploding.
Table of required safety components
Safety Component
SCWS n/ a
Mandatory
Mandatory
Safety Blow Off
n/ a
n/ a
Mandatory
Back End Protection n/ a
Recommended Mandatory
Expansion Vessel
n/ a
n/ a
Mandatory
Alarm n/ a
Recommended
Recommended
Open Vented
– Gravity
Open Vented -
Pumped Pressurised
