Megaflo Main is the new name for the Main unvented cylinder range. This model replaces the Main 170 Litre Indirect Unvented Hot Water Cylinder (5133563).
The cylinder features a 22mm stainless steel coil-in-coil heat exchanger with a 16kW rating for heat transfer from the primary heating system. Its 50mm factory-injected polyurethane insulation helps minimise standing heat loss, while the supplied 18-litre expansion vessel, pressure reducing valve, T&P relief valve and 2-port motorised valve support the specified unvented system configuration.
170 Litre Capacity
Indirect Unvented
16 kW Coil
25 Year Inner Vessel Warranty
Standing Heat Loss
1.92 kWh/24h
Applications & suitability
Medium-Sized Homes
The 170-litre capacity is suited to medium-sized residential properties requiring stored mains-pressure hot water.
One or Two Bathrooms
Designed for homes with one or two bathrooms requiring reliable domestic hot water storage.
Boiler-Heated Systems
The indirect design allows heating through a compatible gas, oil or system boiler via the primary coil.
Domestic Hot Water Storage
A practical unvented cylinder option where mains-pressure hot water storage and indirect heating are required.
Key specifications
| Product Code |
7912279 |
| Type |
Indirect Unvented |
| Nominal Capacity |
170 Litres |
| Height (A) |
1241 mm |
| Diameter |
Ø 550 mm (cylinder) / 595 mm (base) |
| Weight (Empty) |
35 kg |
| Coil Rating |
16 kW |
| Coil Heat-Up Time |
33 mins |
| Recovery Time |
25 mins |
| Standing Heat Loss |
1.92 kWh/24h |
| ErP Energy Rating |
C |
| Operating Pressure |
3.5 bar |
| Expansion Vessel |
18 litre (supplied) |
| Connections |
22mm compression / ¾" BSP |
Installation & compatibility
The Megaflo Main 170 Litre Indirect Unvented Hot Water Cylinder is designed for indirect heating from a compatible gas, oil or system boiler. The 22mm stainless steel coil-in-coil heat exchanger has a 16 kW rating, while the factory-fitted 3.0 kW Incoloy 800 immersion heater provides backup heating capability. The cylinder operates at a specified 3.5 bar pressure and is supplied with an 18-litre expansion vessel, T&P relief valve, pressure reducing valve, 2-port motorised valve and factory-fitted controls.
Design & performance benefits
Coil-in-Coil Heat Exchanger
The 22mm stainless steel coil-in-coil heat exchanger is rated at 16 kW and provides the primary heat transfer system for indirect heating.
Stainless Steel Construction
The high-grade stainless steel inner vessel is pressure tested to 15 bar and is covered by a 25-year inner vessel warranty.
50mm PU Insulation
Factory-injected 50mm CFC/HCFC-free polyurethane foam insulation helps minimise heat loss from the stored hot water.
Backup Immersion Heater
A factory-fitted 3.0 kW Incoloy 800 alloy immersion element at 240V provides backup heating capability.
Additional installation features
Unvented System Components
Supplied with an 18-litre expansion vessel, T&P relief valve, pressure reducing valve and factory-fitted controls.
Motorised Valve
Includes a 2-port motorised valve for primary over-temperature protection as specified for the cylinder.
KIWA & G3 Compliance
KIWA approved and specified as compliant with Building Regulation G3 and Water Regulations, with CE marking.
Ideal for
Medium-Sized Homes
A 170-litre cylinder for domestic properties requiring stored hot water for everyday household use.
One or Two Bathrooms
Suitable for homes with one or two bathrooms and a requirement for mains-pressure stored hot water.
Main System Boiler Installations
Pairs with Main Eco Compact System or Main Eco Elite System boilers for an indirect domestic hot water setup.
Replacement & New Installations
Suitable for domestic cylinder replacement projects and new installations requiring a 170-litre indirect unvented cylinder.
The Megaflo Main 170 Litre Indirect Unvented Hot Water Cylinder 7912279 combines 170-litre storage, a 16 kW stainless steel coil-in-coil heat exchanger and a factory-fitted Incoloy 800 immersion heater. With 50mm polyurethane insulation, a 3.5 bar operating pressure, KIWA approval, Building Regulation G3 compliance and a 25-year stainless steel inner vessel warranty, it provides a practical solution for medium-sized domestic hot water systems.
