Power shower spares & replacement: Mira, Aqualisa Aquastream & Galaxy
When a power shower starts to misbehave, going cold, losing flow, or refusing to hold temperature, the question is always the same: can I fix it, or is it time for a new one? This guide walks the whole lifecycle in order, so you spend wisely. You will identify exactly what you have, find the right spare if a repair makes sense, weigh up repair against replacement honestly, and, if a new unit is the answer, choose a direct replacement that drops in with the least disruption. It covers the big legacy names, Mira, Aqualisa Aquastream and Galaxy or Showerforce, because those are the units most people are dealing with.
The reason this is worth doing properly is that the choice is rarely obvious from the symptom alone. A shower that has gone cold could need a cheap part or be beyond economic repair, depending on its age and what is still available. Working through the steps in order, identify, diagnose, then decide, stops you either throwing out a unit that only needed a cartridge, or sinking money into one that was never going to last. A few minutes of method here saves both money and a second trip up the ladder.
Identify your power shower model
Everything starts here, because the right spare or replacement depends on knowing exactly what you have. It is tempting to skip ahead and start shopping, but a few minutes spent identifying the unit saves ordering the wrong part or a replacement that does not fit. Work through these steps:
- Find the badge on the unit. Most power showers carry the brand and model name on the front, often near the controls (for example Mira, Aqualisa Aquastream, Galaxy or Showerforce).
- Check the manual or paperwork. The original manual, or any paperwork from when it was fitted, usually names the exact model and its specification.
- Match the shape and controls. If the badge has worn off, note the unit's shape, the layout of the controls, and where the pipes and cable enter, then compare against the brand's ranges. A clear photo helps.
- Confirm before you buy. Search the brand and model, or send a photo to our team, to confirm the exact spare or the nearest current replacement before ordering.
The model name is the single most useful thing to find, because it unlocks both the right spare and the correct like-for-like replacement.
Find the right spare
If your unit is sound and the model is current, a single spare part is often all it needs. The most common power-shower spares are the thermostatic cartridge (the valve that controls and stabilises temperature, the usual culprit when a shower runs hot and cold), the pump or impeller (which boosts the flow, suspect it if the shower has gone weak or noisy), and the hose, handset and seals (easy fixes for leaks, splits or limescale blockages). Match the part to your exact brand and model, because power-shower parts are rarely interchangeable between units.
A word on limescale, especially in hard-water areas: it is a frequent cause of early failure, so it is worth descaling the showerhead and hose when you fit a new part, to give the repair the best chance. Most non-electrical spares are within reach of a confident DIYer following the manual, but anything touching the electrical supply should be left to a qualified electrician.
It also helps to match the symptom to the likely part before you buy, so you order once. A shower that swings between hot and cold, or no longer holds the temperature you set, usually points to the thermostatic cartridge. A shower that has lost its force, or has become noisy, points to the pump or impeller. Drips, splits and a weak, patchy spray often come down to the hose, the handset or a worn seal. None of this replaces identifying the exact part for your model, but it does tell you where to look first.
Common faults and what they point to
Before you decide anything, it helps to read what your shower is telling you, because the symptom usually points to a cause and a likely cost. A shower that runs hot and cold, or drifts off the temperature you set, most often means the thermostatic cartridge is failing, which is usually a repair. A shower that has lost its force, or has become noisy or rattly, points to the pump or impeller, sometimes a repair, sometimes a sign the unit is wearing out. Water escaping from the unit can be a simple seal, or it can be internal, which is more serious. Tripping the electrics or scorching around the supply is different again, and a reason to stop and call a qualified electrician rather than carry on.
The pattern to watch for is more than one fault at once. A single failed cartridge on an otherwise sound, current unit is a clear repair. Several issues together, on an older or discontinued model, tip the balance towards replacement, because fixing one part only delays the next. Reading the symptoms early, before everything fails at once, often gives you the cheaper choice while it is still available.
Repair or replace?
This is the decision the whole guide builds to, and the honest answer depends on three things: the unit's age, whether parts are available, and the nature of the fault. If the model is current, the part is in stock and the rest of the unit is sound, a spare such as a thermostatic cartridge is usually the cheaper, quicker fix. If the unit is old, the parts are scarce or discontinued, or it is leaking internally or has more than one fault, a like-for-like replacement is usually better value over time. Here is the steer at a glance:
| Lean towards a spare when | Lean towards replacing when |
|---|---|
| The model is current and parts are available | The model is discontinued or parts are scarce |
| One part has failed on a sound unit | Several things have failed, or it leaks internally |
| The unit is relatively young | The unit is old and has worked hard for years |
Putting money into a tired unit can be a false economy, so if it is near the end of its life on more than one count, replacing it usually pays off.
Choosing a direct replacement
If replacement is the answer, the goal is a like-for-like fit: a current unit that lines up with the pipework and cable already on the wall, so you minimise re-plumbing and re-wiring. Match the position of the water inlets and the electrical entry, and roughly the size, so the new unit covers the same footprint and you avoid leaving marks or holes in the tiling. What often improves is the controls, since a modern replacement may add thermostatic stability and a safety stop. The electrical connection should be made by a qualified electrician, even on a straight swap, to meet bathroom wiring regulations.
Where an exact match no longer exists, because a model has been discontinued, the aim shifts to the nearest current equivalent that fits a similar position. A small amount of pipe or cable adjustment is sometimes needed, which a plumber and electrician can handle, and it is still far less work than a first-time installation. If you are unsure which current model best matches your old one, send our team the brand, model and a photo, and they can point you to the closest fit rather than leaving you to guess.
Browse replacement power showers for like-for-like units, or power shower spares if a repair is the better call
Weighing up the cost
Cost usually decides it, so weigh the whole picture rather than just the sticker on a part. A single spare is normally the cheaper outlay today, but factor in fitting if you cannot do it yourself, and the chance that an old unit will need the next part before long. A replacement costs more up front, but on a tired unit it resets the clock, often improves the controls, and can come with a fresh warranty. We have kept actual prices out of this guide on purpose, because they change; check the current price on the spare and on the replacement, then compare them against the age and condition of your unit. As a rule of thumb, repairing a young, sound unit pays off, while pouring money into an old one rarely does.
Brand notes: Mira, Aquastream, Galaxy
A little brand-specific context helps, because these are the units most people are repairing or replacing. Mira is the best-known shower brand, so spares and current equivalents are widely available; identify the exact Mira model, as the range is large and parts differ between models. The Aqualisa Aquastream is a long-running pumped shower fitted in many homes, which makes it a very common candidate for a thermostatic cartridge or a direct replacement. Galaxy and Showerforce are classic legacy power-shower lines, exactly the sort people need to replace, and there is usually a clear modern equivalent that fits a similar position. In every case, confirm what is currently stocked, as ranges and parts availability change over time.
One pattern is worth knowing: the older and more obscure the model, the more likely you are to be choosing a replacement rather than a spare, simply because parts for discontinued units eventually run out. That is not a reason to panic if you own one, but it is a reason to act sooner rather than later if an old unit is already giving trouble, while a like-for-like replacement is still easy to find. Staying with the same brand often makes that swap simpler, as the layout and connections tend to be similar.
Spares & replacement FAQs
How do I identify my power shower model?
Check the badge on the unit, the original manual, or match the shape and controls to a brand range (Mira, Aqualisa Aquastream, Galaxy or Showerforce). The model name is what you need to find the right spare or replacement, so a photo of the unit and badge is worth taking.
Should I repair or replace my power shower?
If the model is current and parts are available, a spare like a thermostatic cartridge is often the cheaper fix. If it is old, parts are scarce, or it is leaking internally, a like-for-like direct replacement is usually better value over the longer term.
Can I get a direct replacement for a Galaxy or Aquastream power shower?
Often yes. These are common legacy units, so you can usually match a current model with similar pipe and cable positions to minimise re-plumbing and re-wiring. See replacement power showers (linking when live).
Are power shower spares specific to the model?
Almost always. A cartridge or pump from one shower will not usually fit another, even from the same brand, so match the part to your exact model rather than buying a generic equivalent. Identify the model first, every time.
Do I need an electrician to replace a power shower?
Yes, for the electrical connection, even on a like-for-like swap. The plumbing can often be reused, but the final electrical connection should be made by a qualified electrician to meet the regulations for electrical work in a bathroom.
How long should a power shower last before it needs replacing?
It varies with use and water hardness, but many power showers give good service for years before wear in the pump or cartridge starts to show, sooner in hard-water areas. Descaling and replacing worn parts extends that, though once several parts are tiring on an older unit, replacement is usually the better value.
Ready to act? Shop power shower spares to repair the unit you have, or shop replacement power showers for a like-for-like swap. Trusted since 1999, with free UK delivery and 365-day returns. Big brands, small prices.