The Megaflo Main 170 Litre Indirect Unvented Hot Water Cylinder (7912279) is a UK-manufactured stainless steel hot water cylinder designed to provide mains-pressure hot water heated indirectly by a gas, oil, or system boiler. With a 170-litre nominal capacity and factory-fitted Incoloy 800 immersion heater backup, it is well suited to medium-sized homes with one or two bathrooms.
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.
At GetPlumb, we strive to provide reliable and cost-effective delivery options to our customers. Please review our shipping policy below.
🆓 Free Local Delivery (Orders £100 & above)
We offer FREE delivery on orders £100 or more
for selected local areas.
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For orders that do not qualify for free delivery, standard
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- For cart weight between 0–2 kg, the shipping cost is £4.50 with a delivery time of 2–4 working days.
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Examples:
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Delivery Time: 2–4 working days
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For oversized items where the product length is 1.5 metres or more:
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Customers can also choose to collect their order from our store in
Reading, UK, at no additional charge. For any questions regarding shipping, please contact our support team at online@getplumb.co.uk.
