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Megaflo Essential Indirect Unvented Cylinders
Regular price
£895.00
Inc. VAT
£745.83
Exc. VAT
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The Megaflo Essential Indirect is Heatrae Sadia's new entry-level indirect unvented hot water cylinder, designed for use with system and heat-only (regular) boilers. Your boiler heats the water through a coil-in-coil heat exchanger, with a 3 kW immersion heater as backup. It also features Megaflo's newly developed internal expansion mechanism, so no separate expansion vessel is needed, plus 50mm polyurethane foam insulation and a 20-year warranty on the stainless-steel inner tank, giving genuine Megaflo performance at a budget-friendly price. Available in 170, 210, 250 and 300 litres.
The Megaflo Essential Indirect is also the official replacement for the discontinued Baxi Indirect and Baxi Assure Indirect cylinders. Looking for an old Baxi code? See the cross-reference table below.
170–300 L4 capacities
Coil-in-coilHeat exchanger
0External expansion vessels
50 mmPU foam insulation
20-yearTank warranty
⚠ G3 Competent Person Required
Unvented cylinders must be installed by a G3 accredited competent person under Building Regulations Part G3. All electrical connections must be made by a qualified electrician, and the Benchmark commissioning checklist completed at handover.
ℹ Indirect, Direct or Heat Pump?
This Indirect model is heated by your system or heat-only boiler (gas, LPG, oil or electric). No boiler? Choose the Megaflo Essential Direct, heated by twin immersions. For an air source heat pump, choose the Megaflo Essential ASHP, whose coil is sized for heat pump temperatures.
🔄 Replacing a Baxi Indirect cylinder?
Baxi has discontinued its Baxi Indirect and Baxi Assure Indirect cylinders and moved its residential range under the Megaflo brand. The Megaflo Essential Indirect is the like-for-like replacement in 170, 210, 250 and 300 litre sizes.
Key Features
New Internal Expansion Mechanism
Megaflo pioneered internal expansion, and the Essential introduces a newly developed internal expansion mechanism. Expansion is accommodated inside the cylinder, so there's no external expansion vessel to buy, mount or maintain.
Coil-in-Coil Heat Exchanger
Megaflo's coil-in-coil heat exchanger provides efficient heat recovery from system and heat-only boilers, with full coil heat-up in 41 to 65 minutes depending on size.
3 kW Backup Immersion
A 3 kW immersion heater keeps hot water flowing if the boiler is off for servicing or repair.
50mm Polyurethane Insulation
50mm of polyurethane foam minimises standing heat loss, keeping water hot between heating cycles.
Stainless Steel, 20-Year Warranty
Stainless-steel inner tank backed by a 20-year manufacturer's warranty. KIWA approved, complying with Water Regulation 4 and Building Regulations G3.
Megaflo Quality, Budget Price
Strong, consistent pressure at every tap and shower at an entry-level price. Ideal for boiler upgrades, landlords, refurbishments and new-build developments.
Technical Specifications
| Parameter | 170L | 210L | 250L | 300L |
|---|---|---|---|---|
| Product code | 7894517 | 7894518 | 7894519 | 7894520 |
| Volume (L) | 174 | 190 | 230 | 276 |
| Height (mm) | 1414 | 1516 | 1766 | 2086 |
| Diameter (mm) | 553 | 553 | 553 | 553 |
| Empty / full weight (kg) | 38 / 212 | 41 / 231 | 48 / 278 | 55 / 331 |
| ErP rating | C | C | C | C |
| Standing heat loss (kWh/24h) | 1.54 | 1.68 | 1.80 | 2.21 |
| Mixed water at 40°C, V40 (L) | 215 | 242 | 295 | 347 |
| Coil heat-up time (min) | 41.1 | 45.9 | 49.8 | 64.9 |
| Coil rating (kW) | 11.0 | 11.1 | 12.4 | 11.2 |
| Coil surface area (m²) | 0.51 | 0.51 | 0.51 | 0.51 |
| Coil pressure drop (bar) | 0.03 | 0.03 | 0.03 | 0.03 |
| Backup immersion (No. × kW) | 1 × 3 | 1 × 3 | 1 × 3 | 1 × 3 |
| Heat-up, immersion (min) | 218 | 232 | 287 | 366 |
| Secondary return | No | No | No | No |
All connections accept 22mm outside-diameter pipe (compression nuts and olives supplied); thread ¾" BSP male parallel to accept standard ¾" BSP female fittings. Data per Heatrae Sadia/Megaflo; information correct at time of publication.
Baxi Indirect Cylinder Replacement Guide
Looking for a Baxi Indirect or Baxi Assure Indirect cylinder? Find your old code below:
| Old Baxi model | Old Baxi code | Megaflo Essential replacement | New code |
|---|---|---|---|
| Baxi 170L Indirect | 7798180 | Megaflo Essential 170L Indirect | 7894517 |
| Baxi 210L Indirect | 7798181 | Megaflo Essential 210L Indirect | 7894518 |
| Baxi 250L Indirect | 7798182 | Megaflo Essential 250L Indirect | 7894519 |
| Baxi 300L Indirect | 7798183 | Megaflo Essential 300L Indirect | 7894520 |
| Baxi Assure Indirect 170i | 7737261 | Megaflo Essential 170L Indirect | 7894517 |
| Baxi Assure Indirect 210i | 7737262 | Megaflo Essential 210L Indirect | 7894518 |
| Baxi Assure Indirect 250i | 7737264 | Megaflo Essential 250L Indirect | 7894519 |
| Baxi Assure Indirect 300i | 7737265 | Megaflo Essential 300L Indirect | 7894520 |
Need a smaller size? The Baxi 125L and 145L Indirect (7798178, 7798179) don't yet have a Megaflo Essential equivalent. The Megaflo Eco Slimline Indirect covers 100–200 litres, or contact us for a Megaflo Eco 125L or 145L Indirect.
Frequently Asked Questions
Is the Megaflo Essential Indirect the replacement for Baxi Indirect cylinders?
Yes. Baxi has discontinued its Baxi Indirect and Baxi Assure Indirect cylinders, and the Megaflo Essential Indirect is the recommended like-for-like replacement in 170, 210, 250 and 300 litre sizes. For example, the Baxi 210L Indirect (7798181) is replaced by the Megaflo Essential 210L Indirect (7894518).
What's the difference between Megaflo Essential Indirect and Megaflo Eco Indirect?
The Essential is the entry-level option, with 50mm insulation, a 20-year tank warranty and an 11–12 kW coil. Megaflo Eco is the premium range, with 60mm insulation, a 30-year duplex stainless-steel tank warranty, faster coil recovery and more versions, including the narrow 491mm Eco Slimline Indirect, SystemFit, SystemReady and Solar PV Ready.
Which boilers work with the Essential Indirect?
It's designed for both system boilers and heat-only (regular) boilers, including gas, LPG, oil and electric models such as the Baxi Amptec S electric system boiler and the Baxi 800 System 2 gas system boiler.
Can I use it with a heat pump?
No. The Essential Indirect coil is sized for boiler flow temperatures. For heat pumps, choose the Megaflo Essential ASHP cylinder, which has a 2–3 m² heat exchanger designed for lower heat pump temperatures.
Does it need an expansion vessel?
No. The Megaflo Essential Indirect uses Megaflo's new internal expansion mechanism, which absorbs thermal expansion inside the cylinder. That saves wall space, parts and installation time.
Does it include a secondary return connection?
No. The Essential Indirect does not have secondary return. If you need one for long pipe runs, consider the Megaflo Eco range.
What size Megaflo Essential Indirect do I need?
As a guide, 170L suits a smaller home with one bathroom, 210L a typical 3-bedroom family home, and 250–300L larger homes with several bathrooms. Check ceiling height too: the 300L model is 2086mm tall. Not sure? Ask our team.
Also in the Megaflo Essential range: Essential Direct (electric) · Essential ASHP (heat pump) · Megaflo cylinder buying guide
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