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Unvented Indirect Hot Water Cylinders (400L - 2500L) Important Please read & understand all these instructions before commencing installation. Please leave this manual with the customer for future reference Megaflo Commercial Product Guide...
Contents Product Specification Introduction General requirements THE BENCHMARK SCHEME Checklist Storage and handling Technical data ErP data information Immersion allocation table Thermostat control schematics Wiring Schematics Limitations Water supply Installation & Commissioning General Installation Cold Water Supply Secondary circulation and De-Stratification Discharge Pipe work Indirect Model Auxillary...
Building Regulation Part L. The Megaflo Commercial unvented water heater can be fed directly from the cold water mains supply to the property without the need for separate feed cisterns or vent pipes. It is supplied complete with all its necessary inlet and safety controls.
Checklist Before commencing installation check that all the components for your Megaflo Commercial unit are contained in the package. The following components are supplied as standard with your Megaflo Commercial unit: • Table 1: Cold Water Inlet Control Kit (as below, depending on model)
To aid installation, the Megaflo Commercial is provided with lifting points located at the top of the unit. To access the lifting eyes please remove the red outlet gromett and the top cover. The weights of the units are noted on Table 5.
25.38 25.66 48.73 51.23 51.56 52.18 52.36 The thermostat temperature settings of the water heater, as 60°C placed on the market by the ErP data supplier Specific precautions that shall be Table 3: Heat loss Data Information taken when the water heater is Notes: See page 17 to 39 assembled, installed or...
Thermostat controls Thermostat/Cut-out All auxillary immersion heaters are fitted with a thermostat which is fitted in the centre of the heater plate and a cut-out which is fitted to the side of the thermostat. These MUST be wired in series with the operating coil circuit of the contactor (not supplied). See figures 4 below and figures 5 &...
Wiring Schematic Single phase wiring schematic Earth Neutral Live Fuse (not supplied) Contactors (not supplied) Live Live marked ‘L’ Earth Earth Neutral terminal marked 'N' Typical head layout for a single phase heater Neutral Cut-Out Temperature 80°C Immersion Heater FIGURE 5: Single phase wiring schematic (Factorey set) Note: The 2 external contactors must be approved...
Limitations • The Megaflo Commercial unvented water heater should not be used in any of the following instances: • 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.
The pressure reducing valve can be connected anywhere on the cold water mains supply prior to the Megaflo Commercial unit. There is no requirement to site it close to the unit, it can be located at a point where the mains supply enters the premises if this is more convenient but you must install a non-return valve just after the reducing valve for ease of maintenance.The pressure reducing valve...
3.5 bar Pressure reducing valve 8 bar Pressure relief valve direction direction Pressure relief discharge Mains water in To cylinder Pressure gauge connections (one each side) 28mm compression connections Figure 07: Cold water combination valve (for 400 & 500ltr) SECONDARY CIRCULATION TYPICAL DE-STRATIFICATION LOOP SYSTEM Hot water outlet...
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6. The tundish, drain valve and motorised valves must be installed away from any electrical components. 7. No valve should be fitted between the 8 bar or 13 bar pressure relief valve and the Megaflo Commercial unit. Unvented Hot Water Cylinder...
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The following extract is taken from the latest G3 Regulations Discharge pipes from safety devices Discharge pipe D1 3.50 Safety devices such as temperature relief valves or combined temperature and pressure and pressure relief valves (see paragraphs 3.13 or 3.18) should discharge either directly or by way of a manifold via a short length of metal pipe (D1) to a tundish. 3.51 The diameter of discharge pipe (D1) should be not less than the nominal outlet size of the temperature relief valve.
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Discharge Pipe work It is a requirement of Building Regulations that any discharge from an unvented system is conveyed to where it is visible, but will not cause danger to persons in or about the building. The tundish and discharge pipes should be fitted in accordance with the requirements and guidance notes of Building Regulations.
Notes: 1) Discharge pipe-work D2 can now be a plastic pipe but only pipes that have been tested to a minimum 110°C must be used. 2) Discharge pipe D2 can now be plumbed in the soil stack but only soil stacks that can handle temperatures of 99°C or greater should be used.
Primary circuit Boiler Selection The Megaflo Commercial Indirect models are suitable for use with most gas or oil fired boilers com- patible 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.
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THAT MAY BE INADVERTENTLY CONTAINED WITHIN THIS DIAGRAM. THE VARIOUS EQUIPMENT MANUFACTURERS SHOULD BE CONSULTED TO CONFIRM THE CORRECT OPERATION OF THEIR PRODUCTS WITHIN THE SYSTEM. Figure 13: 2 port valve in conjunction with a 3 port mid-position valve system (“Y” Plan) MEGAFLO INDIRECT MEGAFLO ECO (DHW) 2-PORT THERMAL CONTROLs PROGRAMMER VALVE (SUPPLIED)
(20Nm or 14.75 ft/lb) as per the Commercial Immersion heater fitting instructions (36006161). Wire up the immersion heater as per Fig 5, page 13 or Fig 6, page 13 or Megaflo Commercial immersion heater fitting instructions. Refill the cylinder and check for leaks. Turn on the supply and set the thermostat temperature to the desired water temperature (60°C - 65°C is...
Fill the indirect (primary) circuit following the boiler manufacturer’s commissioning instructions. To ensure the primary heating coil in the Megaflo Commercial indirect is filled the 2-port motorised valve (supplied) should be manually opened by moving the lever on the motor housing to the MAN OPEN position.
Open hot water tap nearest to the Megaflo Commercial to relieve the system pressure. Open drain valve. If water fails to drain from the Megaflo Commercial vent the unit by manually opening the Temperature / Pressure Relief Valve.
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HEATER(S) AND SHUT DOWN THE BOILER . DO NOT TURN OFF THE WATER SUPPLY. CONTACT A COMPETENT INSTALLER FOR UNVENTED WATER HEATERS TO CHECK THE SYSTEM. DO NOT TAMPER WITH ANY OF THE SAFETY VALVES FITTED TO THE Megaflo COMMERCIAL SYSTEM, IF A FAULT IS SUSPECTED CONTACT A COMPETENT INSTALLER.
The Fault Finding chart will enable operational faults to be identified and their possible causes rectified. Any work carried out on the Megaflo Commercial unvented water heater and its associated controls MUST be carried out by a competent installer for unvented water heating systems. In case of doubt contact the Megaflo Commercial Service Department.
Caution must be taken when drawing water from the unit. Spares Spare parts A full range of spare parts are available for the Megaflo Commercial range. Refer to the Technical Data label on the unit to identify the model installed and ensure the correct part is ordered. KEY DESCRIPTION...
Spares KEY DESCRIPTION SPARES NUMBER CUT-OUT THERMOSTAT 95612652 ROD THERMOSTAT 95980025 2 PORT MOTORISED VALVE (DN 32) 7031564 2 PORT MOTORISED VALVE (DN 40) 7031565 PUMP 3 SPEED CIRCULATION UP 20-30N 95607366 PUMP 3 SPEED CIRCULATION UPS 15-50N 130 95607404 28mm PUMP ISOLATING VALVE 95605177 1/2”...
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Part Part 95:611:025 95:607:396 10-48 43-47 Part Part 95:607:_ _ _ 95:605:_ _ _ 11-14 Part Part 95:605:_ _ _ 95:605:182 17-22 Part Part 95:605:_ _ _ 95:607:452 Unvented Hot Water Cylinder...
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23-25 26-29 Part Part 95:605:_ _ _ 95:605:_ _ _ 30-31 Part Part 7033371 95:612:650 Part Part 95:612:652 95:980:053 35&36 37&38 Part Part 7031564 & 7031565 95:607:_ _ _ Unvented Hot Water Cylinder...
Part Part 95:605:177 95:607:690 Part Part 95:607:691 95:980:009 51-52 Part Part 95:605:110 7031586 & 7031587 55-56 53-54 Part Part 7031595 & 7031596 7031588 - 7035971 Unvented Hot Water Cylinder...
30 years from the date of purchase. All other components, including valves, expansion vessels, immersion heaters, fittings and controls are covered by a two year warranty from the date of purchase of the Megaflo product that includes both parts and labour.
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• The Megaflo product has not been modified or tampered with in any way, other than by a Heatrae Sadia or Baxi Customer Support approved engineer.
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Please contact Baxi Customer Support on 0345 0701058 for details. *In domestic† properties, lifetime is the period during which the first owner of the Megaflo or new build home continues to own the property. Should the property be sold, the new owner and any subsequent owners will receive a 30 year warranty from the date the original owner purchased the Megaflo or new home with a Megaflo installed.
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