Heatrae Sadia makes several ranges of small electric water heaters for washrooms, kitchens, offices and holiday lets: Multipoint, Hotflo, Streamline, Express, R Plus and FBM Eco. They can look alike, but they work in quite different ways. This guide explains how each range works, which suits which job, and where to find the manuals, all taken from Heatrae Sadia's own brochures, data sheets and installation instructions.

The first decision: unvented, vented or cistern type

  • Unvented (Multipoint and Hotflo): sealed heaters that use mains water pressure, so they work with ordinary taps and can feed several basins or sinks. Because they run under pressure, they are fitted with safety valves and need room for expansion. Heatrae's instructions call for a competent installer, and the Multipoint and larger Hotflo manuals specify a competent plumbing and electrical installer working to Building Regulations Part G.
  • Vented open-outlet (Streamline and Express): small heaters connected to the mains through their own vented tap or spout. They are the simplest option for a single basin or a small kitchen sink. While they heat, the water expands and the tap or spout drips a little, which Heatrae notes is normal. Our guide Do I need a vented tap with my vented water heater? explains more.
  • Cistern type (R Plus and FBM Eco): self-contained vented heaters with their own tank. They supply several outlets through standard taps by gravity, so they must be mounted higher than the taps they serve.

The ranges compared

Multipoint 10 and 15

  • Unvented, 10 or 15 litres, 3kW, with a 5 year warranty including on-site support.
  • Supplies several outlets through conventional taps. Heatrae does not recommend these two sizes for a shower. There is more background in our Multipoint range overview.
  • Multipoint 10 and Multipoint 15.

Multipoint Eco 30 to 100 litres

  • Unvented, 30, 50, 80 or 100 litres, all 3kW, in vertical and horizontal versions. Designed for canteens, washrooms and commercial kitchens, and the larger models can also supply a shower.
  • A digital display, smart thermostatic control that recognises and manages high and low demand periods, and Heatrae's Legionella Control System.
  • Duplex stainless steel cylinder with a 15 year inner cylinder warranty and 2 years on all other components, with on-site service.
  • Supplied with a factory-fitted temperature and pressure relief valve and an inlet control kit including the pressure reducing valve and an expansion vessel (8 litres on the 30 and 50, 12 litres on the 80 and 100).
  • Vertical models: 30 litre, 50 litre, 80 litre, 100 litre. Horizontal models are on our Multipoint page.

Hotflo

  • Unvented, with no need for a cold water cistern, and works with standard or mixer taps.
  • Hotflo 10 and 15: 2.2kW, designed for smaller businesses needing hot water at two or three sinks and basins, with a 2 year warranty. Hotflo 10 and Hotflo 15.
  • Hotflo 50, 80 and 100: 3kW, vertical or horizontal, duplex stainless steel with a factory-fitted temperature and pressure relief valve, a 2 year warranty and a 5 year inner cylinder warranty. The Multipoint Eco's digital display and Legionella Control System are not listed on the Hotflo data sheet. See the Hotflo range.

Multipoint Instantaneous

  • Stores no water, so the unit is compact at 210 x 160 x 104mm. Heatrae suggests it for remote locations, garages, cloakrooms, and student or holiday accommodation.
  • Supplies a shower and a tap, one outlet at a time. 7kW or 9kW, needing a 30A or 40A double pole isolating switch respectively, and a water pressure of 1 to 7 bar. 2 year warranty.
  • Multipoint Instantaneous 7kW and 9kW.

Streamline

  • Vented, slim, in undersink and oversink models, 7 or 10 litres, 1kW or 3kW. Ideal for single washrooms and small office kitchens. 2 year warranty.
  • Works at 0.34 to 2 bar; above 2 bar a pressure reducing valve is needed.
  • Popular sizes: 7 litre 3kW undersink and 7 litre 3kW oversink. All eight are on our Streamline page.

Express

  • Vented, Heatrae's original water heater, with a tough metal case. Fits under or over the sink, with a telescopic spout over the sink or taps under it. 2 year warranty.
  • 7 litres at 1kW or 3kW, and 15 litres at 3kW. See the Express 7 litre 3kW and the Express range.

R Plus and FBM Eco

  • Cistern type, 25, 45, 70 or 120 litres, 3kW. Self-contained, needing no special taps, for washrooms with several sinks and commercial kitchens.
  • Mounted higher than the taps they supply. Heat-up times are 30, 50, 80 and 135 minutes for the 25, 45, 70 and 120 litre sizes.
  • FBM Eco: can be controlled at the unit or remotely through a building management system (BMS), with a 5 year warranty. Heatrae suggests it where there are no outside walls near enough for discharge pipes. See the FBM Eco range.
  • R Plus: Heatrae's modern replacement for traditional cistern-fed units, with a 2 year warranty. See the R Plus range.

Which one suits your job?

  • One basin or a small kitchen sink: a Streamline or Express is the simplest fit. If you want ordinary taps at mains pressure, look at a Multipoint 10 or Hotflo 10.
  • Two or three sinks and basins: Hotflo 10 or 15, or a Multipoint 10 or 15.
  • A busy washroom, canteen or several outlets with only a mains supply: Multipoint Eco 30 to 100, or Hotflo 50 to 100. Heatrae describes the unvented range as serving up to ten basins or sinks.
  • A shower: a larger Multipoint Eco, or a Multipoint Instantaneous where there is no room for a tank.
  • Several outlets on standard taps, without unvented discharge pipework: R Plus or FBM Eco, sited above the taps.

Still deciding whether point of use is right at all? Our comparison of point of use and centralised water heaters covers that choice for commercial buildings.

Multipoint Eco heat-up and recovery

Heatrae's figures for the vertical models, with recovery being the time to reheat after use and V40 the volume of mixed water at 40°C available:

  • 30 litre: 37 minutes to heat, 26 minutes to recover, 51 litres at 40°C.
  • 50 litre: 65 minutes to heat, 46 minutes to recover, 80 litres at 40°C.
  • 80 litre: 115 minutes to heat, 81 minutes to recover, 132 litres at 40°C.
  • 100 litre: 125 minutes to heat, 88 minutes to recover, 162 litres at 40°C.

The horizontal versions heat and recover faster at each size: 29, 51, 74 and 98 minutes to heat. For what recovery time means in practice, see our guide to the recovery time for an electric water heater.

Kits and accessories

More parts are on our Heatrae Sadia accessories page.

Heatrae Sadia manuals and data sheets

Heatrae Sadia's own documents, free to download. Check the product code on your heater's rating label against the codes listed in each one.

Quick answers

What is the difference between a Multipoint and a Hotflo?

Both are unvented. At 10 and 15 litres the Multipoint is 3kW with a 5 year warranty and the Hotflo is 2.2kW with a 2 year warranty. At 50 to 100 litres the Multipoint Eco adds a digital display, smart controls, Legionella control and a 15 year inner cylinder warranty, against 5 years on the Hotflo.

Why does my Streamline or Express tap drip while it heats?

The water expands as it heats and pushes a little out through the open outlet. Heatrae's instructions say this is normal and not a fault, and warn that overtightening the valve can damage it.

Can a point of use water heater run a shower?

The larger Multipoint Eco models can, and the Multipoint Instantaneous supplies a shower and a tap. Heatrae does not recommend the Multipoint 10 and 15 or the Hotflo 10 and 15 for a shower.

Who can install one?

Heatrae's instructions call for a competent installer on every range. The Multipoint and larger Hotflo manuals specify a competent plumbing and electrical installer working to Building Regulations Part G, with section G3 cited in the Multipoint manuals.

Not sure which one you need?

Call us on 01934 253600, or send a photo of your current heater or its rating label on WhatsApp to 07340 354023, and we will help you choose. You can browse every model on our Heatrae Sadia water heating page. Free delivery over £150 ex VAT.