Description Of The Product; General Description; Operation Principle; Main Components - Heatrae Sadia Megaflo Eco SystemFit 145sf Instructions Manual

4. Description of the product

4.1 General description

This product is a purpose designed unvented water
heater. The unit has a stainless steel inner vessel, which
ensures an excellent standard of corrosion resistance. The
outer casing is a combination of resilient thermoplastic
mouldings and pre-coated steel. All products are
insulated with CFC free polyurethane foam to give good
heat loss protection.
The unit is supplied complete with all the necessary safety
and control devices needed to allow connection to the
cold water mains. All these components are preset and
should not be tampered with.

4.2 Operation principle

The unvented cylinder is used to heat and store hot water
for use in domestic.
Depending on the model the water can be heated directly
using Immersion heater(s) or indirectly through a coil in
the unit using an indirect heat source.
4.3 Main connections
See Figures 6 : Main connections on page 13

4.4 Standard delivery

The delivery includes:
` Cylinder
` Factory fitted
` Immersion heater(s) and thermal controls
` Temperature and Pressure Relief Valve (set at 90ºC /
1 Mpa (10bar))
` Indirect thermostat and thermal cut-out
`
8 bar pressure relief valve (incorporating a check
valve)
` Tundish
` T&P relief valve insulation set
` Drain valve
` Wiring centre
` 3 x 2 Port motorised valve
` Primary circulation pump
` Lock shield flow balancing valve
`
Differential bypass valve
`
Filling Loop, straight
` Primary circuit pressure gauge
` Drain valve (with quarter turn lever)
` Literature pack
` Instructions (inc benchmark commissioning checklist
& service record)
` Fixing template
` 3 bar pressure reducing valve (incorporating strainer)
`
Automatic air vent
`
Stop cock
` Lifting handle
` CH/DHW programmer and room temperature sensor
` Primary circuit expansion vessel (including wall
mounting bracket)
` CH second zone room thermostat/programmer
4.5 Storage and Handling
If the unit is to be stored before installation it must be
placed upright on a secure, level surface and be in a dry,
frost free environment. The support surface must be
capable of supporting the packaged weight of the unit,
the packaged weights are displayed on the carton label.
Please take care when handling a packaged cylinder. The
units are heavy and must only be moved manually using
safe working practices. The package weights of each unit
are displayed on the carton label. Once removed the units
can be lifted by screwing the lifting handle provided onto
the outlet boss, but again take note of the unit weights
when deciding on a safe lifting method. DO NOT use the
factory fitted T&P relief valve to lift or manoeuvre the
unit.

5. Before installation

5.1 Installation regulations

WARNING
Installation of the appliance must be carried
out by a qualified engineer in accordance
with prevailing and national regulations as
listed below.
` Building Regulations G3
` The Building Standards (Scotland)
` The Building
Ireland)
` I.E.E Electrical Regs
` UK Water Regulations

5.2 Installation requirements

Water supply
In an unvented system the pressure and flowrate is directly
related to the incoming water supply. For this reason it
is recommended that the maximum water demand is
assessed and the water supply checked to ensure this
demand can be satisfactorily met.
` We suggest the minimum supply requirements
should be 0.15MPa (1.5 bar) pressure and 20 litres
per minute flow rate. However, at these values outlet
flow rates may be poor if several outlets are used
simultaneously.
`
A 22mm cold water supply is recommended,
however, if a smaller supply exists, which provides
sufficient flow, this may be used (although more
flow noise may be experienced).
` The higher the available pressure and flow rate the
better the system performance.
` See table 1 on page 5 for cylinder operating pressures.
This is controlled by the cold water combination
valve assembly.
`
The water supply must be of wholesome water
quality (Fluid Category 1 as defined by the Water
Supply Regulations 1999).
Regulations (Northern
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