Zip's wall-mounted boilers give a kitchen, office or staff room instant boiling water from a tap, without a queue at the kettle. This guide compares the three ranges, shows what each size delivers so you can pick the right one, explains the common faults and the spares that fit, and links to Zip's manuals, all taken from Zip's own brochure, installation manuals and parts lists.

EconoBoil, HydroBoil or HydroBoil Plus?

All three use Zip's twin chamber design, which keeps incoming cold water separate from the boiling water, and its Steam-Heat-Boost system, which uses steam to pre-heat the incoming water. The differences are in features, sizes and warranty.

EconoBoil

  • Zip's value range, in 3 and 5 litre models.
  • Two-way chrome-plated tap, insulated PPS boiling tank and a white enamelled steel case.
  • 1 year on site parts and labour warranty.

HydroBoil

  • The widest choice of sizes, from 3 to 40 litres.
  • PPS boiling tank up to 7.5 litres and a stainless steel tank on the larger models, with premium insulation and a heating cycle indicator.
  • The tap locks on to fill pots hands-free.
  • 2 year on site parts and labour warranty.

HydroBoil Plus

  • Zip's most advanced model, in 3, 5 and 7.5 litres.
  • A cool-touch two-way tap and a safety lock that stops boiling water being dispensed by accident.
  • Power-Pulse energy saving, a timer and a low-light sleep mode, with a display showing the time, heater operation and energy saving status.
  • 2 year on site parts and labour warranty.

Which size do you need?

Zip rates each model by two figures: how many cups it holds ready at one time, and how many it can make in an hour. Size for your busiest moment, such as a morning or lunchtime rush, using the first figure, then check the hourly figure covers steady use through the day. A cup here is 167ml.

Two things often decide it. Every model up to 25 litres is rated under 3kW and runs from a 13A supply through a double pole isolating switch or socket, while the 40 litre model needs its own 32A supply. And the larger models are bigger on the wall: the 25 litre is 786mm tall against 439mm for a 3 litre, so check the space.

What installation needs

  • Fitting by a qualified tradesperson, to Zip's instructions.
  • A position over a sink, draining board or drip tray, with the tap outlet at least 280mm (nominally 360mm) above it, and service clearance of 150mm above, 65mm to the left and 20mm to the right.
  • A drinkable water supply giving at least 2 litres a minute at 1 bar, with a service valve, and a pressure reducing valve if the pressure is likely to exceed 5 bar.
  • A vent pipe to a visible tundish, then to a drain in 15mm pipe with a continuous fall, no more than 3 metres long and with no more than 3 right angle bends, because the vent can discharge steam or boiling water.

Common faults and what causes them

Zip's fault table lists these symptoms and causes. The first checks are simple, but anything inside the case is a job for a qualified engineer: Zip's instructions are to isolate the power before the cover comes off, and that service work is done by suitably qualified tradespeople.

  • No water from the tap: first check the water isolating valve is open. Otherwise Zip lists a blocked filter, metering tube or strainer, a jammed ball valve, or an airlock in the transfer tube.
  • Water not boiling: first check the power supply. Otherwise Zip lists a faulty element, a faulty cut-out, or a faulty thermostat on older HydroBoils and a faulty PCB on current models.
  • Runs out and does not refill, a dripping or leaking tap, overflow or excess steam from the vent, or the overload keeps tripping: Zip lists an internal adjustment, a blocked vent or incorrect venting, all for an engineer.

On a HydroBoil Plus, the display shows when there is a fault, and the Info menu lists the current faults, which is worth noting before you call anyone.

Spares for HydroBoil and EconoBoil

Start with the product code on your boiler's rating label. Current models have codes beginning 40 (such as 405552), while the earlier generation used codes beginning 30, and some parts differ between them, so the code is the safest check. Genuine Zip parts we stock for these boilers include:

You can see every Zip part we carry on our Zip parts page.

Zip HydroBoil and EconoBoil manuals

Zip's own documents, free to download. Each lists the model codes it covers, so match it to the code on your rating label.

Hard water and limescale

Zip warns that in hard water areas, scale can build up in the boiling chamber, and that some form of water treatment may be needed. Its inline filters reduce limescale as well as improving taste and odour: the FL064 for models up to 7.5 litres and the FL104 for 10 litres and above.

Quick answers

What is the difference between an EconoBoil and a HydroBoil?

At 3 and 5 litres their output is the same. The HydroBoil adds a 2 year warranty instead of 1, a heating cycle indicator, and sizes up to 40 litres.

Can a HydroBoil plug into a normal socket?

Models up to 25 litres are rated under 3kW and connect to a 13A double pole isolating switch or socket. The 40 litre model needs a separate 32A supply.

How long does it take to heat up from cold?

With a 15°C inlet, Zip quotes 11 minutes for a 3 litre, 12 for a 5 litre, 18 for a 7.5 litre and 52 for a 25 litre.

Can I fit the spares myself?

Zip states that installation and service work should be done by trained, suitably qualified tradespeople, and that the power must be isolated before the cover is removed.

Not sure which model or part you have?

Call us on 01934 253600, or send a photo of the rating label on WhatsApp to 07340 354023, and we will confirm the right size or part. You can browse the whole range on our Zip HydroBoil and EconoBoil page, or read our comparison of alternatives to the Zip HydroBoil. Free delivery over £150 ex VAT.