Mixergy iHP X FAQ

Mixergy iHP X combines a hot water tank and an air source heat pump in one product. It collects warmth from the surrounding air and transfers it into the water.

It normally heats water through longer, lower-power cycles. This can feel different from a boiler or direct electric tank, but it does not mean the product is heating incorrectly.

How iHP X heats your water

The heat pump is built into iHP X. A standard cylinder usually uses a separate boiler, an electric immersion heater or an external heat pump. An immersion heater is an electric element inside the tank that heats the water directly.

A combi boiler heats water when you open a hot tap. iHP X stores hot water and prepares it ahead of time, so its normal heating cycles take longer. Use a heating plan that allows water to be ready when the household needs it.

Everyday use

Leave iHP X switched on. Use a suitable manual schedule or Mixergy Flex, the automatic scheduling option that learns when your household uses hot water. You do not need to change settings every day. See Set schedules and smart control if you manage the settings yourself.

• Keep the air openings and service access clear. Do not store items against the unit.
• Use Boost for unexpected extra demand, with time for the water to heat.
• If you manage the energy account, check the tariff details after changing supplier or contract. Follow Set your energy tariff.
• Do not remove covers or alter the air ducting.

When to ask for help

If you rent, contact your landlord or housing provider. Homeowners should contact the installer if the household repeatedly runs out of hot water or the product shows a fault.

Also report a leak, a damaged air grille or new loud noises. If there is no air moving while the heat pump is supposed to be running, record any displayed message and ask for help. Do not open the heat-pump section to investigate.

For smoke, fire or immediate danger, leave the area and call the emergency services. For a burning smell or equipment that appears unsafe, stop ordinary checks and use the urgent repair route.

Common questions

How do I ask for more hot water, and how long will it take?

Find the gauge: the panel with lights and up/down buttons on the tank. Press the up arrow to increase the requested level. Green lights show extra water requested, which is waiting to heat or heating. They turn red as that water becomes ready.

Boost is not instant hot water. Heat pump heating normally takes longer than direct electric heating. Fewer than ten red lights can be the finished amount you requested and enough for your needs. If you use the app, sign in, select your tank and choose Boost on its Controls or Hot Water screen. See Set hot water levels and use Boost for the steps.

Why does it heat at night?

An automatic or manual heating plan can prepare water overnight for the morning. Where your energy tariff has cheaper hours, those hours can also influence heating. Nighttime operation alone does not mean there is a fault.

If you manage the settings, open the app, select your tank and use the top-right menu to open Mixergy Flex. Standard or Economy means automatic scheduling is enabled; Off means manual scheduling. Follow Set schedules and smart control before changing the plan. If housing staff manage it, ask them to check the heating times.

What sounds are normal?

A steady hum from the fan or compressor can be normal, similar to a refrigerator. The sound can change when a heating cycle starts or stops. Report a new loud noise, grinding or repeated unusual sounds to the installer or housing provider.

Does it cool the room, and what needs to stay clear?

The heat pump takes warmth out of the air it uses. Whether the room feels cooler depends on the installed air supply and ducting. Ducting means the pipes or channels that carry air to or away from the unit.

Keep air openings and grilles clear. Do not cover them, box in the heat-pump section or change the ducting. If the room feels unusually cold or damp, ask the installer or housing provider to check the arrangement.

Why is the immersion heater running?

It can provide configured backup or help finish the automatic cleansing cycle, which heats stored water throughout to help control Legionella bacteria. This alone does not mean the heat pump has failed.

Ask the installer to check the setup if the immersion heater runs frequently and you do not know why. Leave temperature and installer settings unchanged. See Why does your tank heat to full every two weeks? for more about cleansing.