HAMWORTHY HEATING LTD
LILLIPUT HE
500001047/F
8
To comply with guidance note PM5 (Health and
Safety Executive), the minimum pressure
requirements at the boiler are given below as
examples:-
a.
Single installed boiler running at 82
o
C flow
temperature. Minimum head required is not less
than 2 metres or 0.2 bar.
b.
Single installed boiler running at 95
o
C flow
temperature. Minimum head required = 5.1 metres
or 0.5 bar.
c.
Multi boiler installation running at 82
o
C flow
temperature and 11
o
C rise across system. Minimum
head required = 4.3 metres or 0.42 bar.
d.
Multi boiler installation running at 82
o
C flow
temperature and 20
o
C rise across system.
Minimum head required = 9.3 metres or 0.92 bar.
5. CONNECTIONS
5.1 Fuel
GAS
- For burner gas train inlet connection sizes,
refer to Section 2.1.
A manual shut-off valve must be fitted on the
incoming gas supply pipe. It shall be adjacent to
boiler, clearly identified and readily accessible.
OIL
- All burners are supplied with flexible oil pipes
to make the final connection between the oil supply
pipe and burner. The oil supply line should
terminate adjacent to the burner with an isolating
valve and metal bowl filter.
5.2 Water
The flow and return water connections are located
on the rear section of each boiler. These are tapped
Rc 1½" (1½" BSP female tapered thread). Refer to
Fig. 1(Page 3).
5.3 Electrical
WARNING: THIS APPLIANCE MUST BE
EARTHED.
IMPORTANT:
All wiring must be installed in
accordance with the IEE Wiring Regulations for
electrical installations, and any other local electrical
regulations which apply.
A 240 volt 50 Hz single phase neutral and earth
supply is required. Entry points for the electrical
cable are located on the back casing panel.
To allow electrical isolation of the boiler when
necessary the electrical supply should come from a
double pole fused isolator (located in the boiler
4.4 Safety
Valve
A pressure relief (safety) valve, of approved
manufacture and sized to match the boiler(s) rating
in accordance with BS.6644, should be installed in
the flow pipe between the boiler(s) and open vent
pipe connection. The safety valve discharge pipe
should be self draining and terminate in a visible
position where any discharge will not be a danger to
personnel.
4.5 Pressure
Gauge
The boiler(s)/heating system should be fitted with a
water pressure gauge to indicate the pressure in the
system in either metres of water or bars.
4.6
Thermometer (temperature gauge)
Each boiler control panel incorporates a
temperature gauge, indicating the temperature of
the boiler flow water in degrees Celsius.
4.7 Drain
Valves
A drain valve (not supplied) should be fitted to allow
complete draining of the boiler when necessary.
Any parts of the system which are below the boiler
should have a drain valve installed at the lowest
point to allow the system to be totally drained when
necessary. A plugged Rc½" connection is provided
for a drain valve at the bottom of the front boiler
section.
4.8
Feed Water Quality
If the boiler feed water has a high degree of
hardness, it is recommended that the water be
treated to prevent precipitation of scale or sludge in
the boiler water passageways. Details of additives
can be obtained from any reliable
manufacturer of water treatment products or the
local water authority.
It should be noted however, that even if the boiler
water is of average hardness, not requiring
treatment, subsequent draining of the system for
repair or constant make-up water due to an
undetected leak will cause additional deposits and
gradual build-up of scale. It is essential therefore,
that leaks are attended to promptly and draining is
kept to an absolute minimum.
It is recommended that the system be flushed out at
least twice when hot before any water treatment is
added. If any doubt exists regarding the internal
cleanliness of an old system, consideration should
be given to the fitting of a coarse filter in the return
pipework to the boilers.
4.9
Minimum System Water Pressure
