MEGAFLO Eco SolaReady, Product Manual

INST

ALLA

TION

18

Indirect Model

Boiler Selection
The Megaflo Eco SolaReady Indirect models are supplied with an auxiliary heating coil and are suitable for use with most gas 
or oil fired boilers compatible with unvented systems i.e. fitted with a temperature control thermostat and thermal cut-out. If 
in doubt consult the boiler manufacturer.  Solid fuel boilers or any other boiler in which the energy input is not under effective 
thermostatic control, unless additional and appropriate safety measures are installed, SHOULD NOT be used.  The boiler used 
can either be a sealed system or open vented type, maximum primary circuit pressure  0.3Mpa (3 bar).  The primary flow 
from the boiler MUST be pumped. Gravity circulation will not work due to the special design of the primary heat exchanger. 
It is recommended that an air bleed point or automatic air vent is incorporated in the primary return pipework close to the 
Megaflo Eco SolaReady unit.  The boiler flow temperature should usually be set to 82ºC (maximum flow temperature to 
primary heat exchanger 89ºC).  The boiler cannot be vented through the Megaflo eco Solar unit.

Indirect Thermal Cut-Out And 2-Port Motorised Valve
To comply with Building Regulations, and to prevent the Megaflo Eco SolaReady from overheating the 2-port motorised valve 
supplied MUST be fitted to the primary flow to the indirect coil (see Figure 6).

Wiring
All electrical wiring should be carried out by a competent electrician and be in accordance with the latest I.E.E. Wiring 
Regulations.
The Megaflo Eco SolaReady Indirect combined thermostat and thermal cut-out are factory pre-wired. The 2-port motorised 
valve supplied MUST be wired in series with the Indirect controls such that the power supply to the valve is interrupted should 
either the Thermostat or Thermal cut-out operate. Figure 16, diagrams A, B, D and E detail the wiring required between these 
controls and the motorised valve. Wiring to external controls is made via the terminal block fitted. The cable should be routed 
through the aperture in the terminal cover and secured using the cable grip provided. The Indirect Thermal cut-out MUST NOT 
be bypassed.

Heating System Controls
The controls provided with the Megaflo Eco SolaReady will 
ensure the safe operation of the Megaflo Eco SolaReady 
within a central heating system. Other controls will be 
necessary to control the space heating requirements and 
times that the system is required to function. Depending on 
the boiler selected, heating circuit design and controls used it 
may be beneficial to incorporate a system bypass in the 
heating system pipework.
The Megaflo Eco SolaReady is compatible with most heating 
controls, examples of electrical circuits are given in the block 
wiring schemes. However, other systems may be suitable, 
refer to the controls manufacturers’ instructions, supplied 
with the controls selected, for alternative system wiring 
schemes.
The auxiliary indirect heating source can be controlled via the 
Solar Differential Controller – refer to block wiring schemes 
B and E and Commissioning Section for setup details.
NOTE: The auxiliary backup immersion heater must have a 
separate 13 amp fused supply and cannot be operated via the 
Solar Differential Controller on indirect models.

Immersion Heater(s)
The Megaflo Eco SolaReady indirect units (Indirect models) are supplied with an immersion heater which can be used as an 
alternative heat source should the boiler supply need to be isolated from the Megaflo Eco SolaReady unit. The immersion 
heater is located within the upper controls housing. Refer to page 17 “Wiring and Operation” for details of wiring and 
operation of the immersion heater.

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Control Housing Details

Element Connections

1.5mm² 3 Core
HOFR sheathed 
cable

Indirect control
wiring

Figure 15 – Control housing details