System Details; (And By-Pass Requirements) - Baxi Solo 2 60 RS Installation And Servicing Instructions

System Details - Page 8

(and By-pass Requirements)

Water Circulating Systems
The appliance is suitable for use with fully pumped open vented
systems (small bore and micro-bore), gravity domestic hot water
with pumped central heating systems and sealed systems.
The following conditions should be observed on all systems:
•
The static head must not exceed 30m (100ft) of water.
•
The boiler must only be used with an indirect cylinder.
•
Drain points should be fitted to the lowest points in the
system.
•
All electrical wiring, gas and water pipes must be installed
in a way which would not restrict the servicing of the boiler.
•
Position isolating valves as close to circulating pump as
practicable.
•
For fuel economy and best boiler performance, the system
should be designed so that gravity circulation does not take
place in the heating system when the pump is not running.
Treatment of Water Circulating Systems
For optimum performance after installation, this boiler and its
associated central heating system must be flushed in
accordance with the guidelines given in BS7593:1992
"Treatment of water in domestic hot water central heating
systems".
This must involve the use of a proprietry cleanser, such as
BetzDearborn's Sentinel X300 or X400, or Fernox's Superfloc.
Full instructions are supplied with the products but for
immediate information please contact BetzDearborn on 0151
420 9563, or Fernox on 01799 550811.
For long term protection against corrosion and scale, after
flushing it is recommended that an inhibitor such as
BetzDearborn's Sentinel X100, or Fernox's MB-1 or Copal is
dosed in accordance with the guidelines given in BS7593:1992.
Failure to flush and add inhibitor to the system may
invalidate the appliance warranty.
BYPASS REQUIREMENTS
•
The boiler is fitted with a pump overrun device which allows
the removal of residual heat from the boiler. NOTE: The pump
overrun will operate for approximately 3 minutes. The system
design must therefore always provide an open circuit for water
to circulate between the boiler flow and return.
•
If a system has an open circuit a bypass is not required.
•
A system using a 3 port diverter valve does not normally
require a bypass and therefore this system is recommended.
The exception to this is where all radiators in the system are
fitted with thermostatic valves, in which case a bypass would be
required. However, if one radiator in such a system was fitted
with 2 lockshield valves a bypass would not be required.
•
A system controlled by non-electrical valves e.g.
mechanical thermostatic control valves both on the radiators
and the hot water circuit and systems using twin zone valves
(e.g. Honeywell 'S' Plan) will require a bypass.
The bypass circuit can be:-
A) A minimum of 9 metres of 22mm pipe (measured between
the boiler flow and return connections). It should be fitted with a
lockshield valve opened at least 1 full turn to give a minimum
flow rate of 8 litres/mm (1.8 gal/mm).
B) A radiator fitted with lockshield valves. The radiator output
should be a minimum of 800 watts (2,700 Btu/h). Typically a
convector type radiator with an area of 3750 cm
adequate.
C) By including an automatic bypass valve in the system (see
diagram).
D) Any circuit that provides the same operating conditions as
option A or option B.
8
2 2
(4ft ) is