Triton Shower goes cold during usewhat to check
Triton problem 5, and their published answer is one line: the water pressure dropped below the minimum, so wait until it comes back.
Before you start
What this means
Triton distinguish this from a shower that runs cold from the start, and the distinction is the whole diagnosis. A shower that never heats is an appliance or supply problem. A shower that starts fine and goes cold partway through is almost always something changing while you are in it, and Triton attribute it to one thing: the water pressure has dropped below the minimum required.
Their action is correspondingly short — wait until the water pressure resumes to normal. That reads as a brush-off and it is not. It follows directly from how their low pressure cut-out works: when pressure falls below the threshold, the shower removes power from the elements and lets the water keep flowing, and it puts the power back automatically once pressure returns. So a mid-shower drop to cold with the water still running is the documented, expected behaviour of a shower whose supply has faltered, and it will fix itself.
What is worth doing is working out why the pressure moves. Something in the property is usually the answer rather than the street. A washing machine or dishwasher filling, a toilet cistern refilling, somebody running a tap downstairs, or an outside tap left on will all pull a marginal supply below the threshold for a minute or two. In a house with a genuinely strong mains you can run several outlets without the shower noticing; in one where the incoming supply or the pipework is marginal, the shower is the most sensitive thing in the building and it becomes an accidental pressure gauge.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Another outlet drawing water at the same time | A machine filling, a cistern refilling or a tap running. The commonest reason a marginal supply dips for a minute mid-shower. | Common |
| Marginal incoming mains pressure | A supply that sits just above the shower’s minimum has no margin, so ordinary household demand takes it below. | Common |
| Partly restricted supply to the shower | A silted inlet filter or a part-closed servicing valve reduces the margin further, turning an occasional dip into a regular one. | Occasional |
| Street pressure varying at peak times | Out of your hands and usually predictable — the same time every morning. Worth identifying so you stop looking at the shower. | Occasional |
What to try yourself
Notice what else is running when it happens. A washing machine, a dishwasher or a refilling cistern is the usual culprit and it is a two-minute observation.
Shower with nothing else drawing water and see whether it holds temperature. If it does, the shower is fine and the supply is the constraint.
Check the servicing valve on the shower feed and the main stopvalve are fully open, which is Triton’s own check for a mains-fed unit below minimum pressure. If the filter inside the unit has never been cleaned, that recovers margin too, but on a Triton it is an engineer’s job: it is behind the cover and the shower is recommissioned afterwards.
If it happens at the same time every day regardless of what is running indoors, that is street pressure and no work on the shower will change it.
Where the supply genuinely cannot support the shower, a pumped unit or a different system is the answer rather than a repair.
Get a qualified electrician to look at your Triton electric shower
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified electrician, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
What it costs to fix
Typical repair cost
£0–£90
Time on site
15 minutes
Nothing in most cases, since the shower recovers on its own. A valve is free; a filter clean is a short engineer visit on a Triton; a genuinely inadequate supply is a pump rather than a repair.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Triton fault codes
- Low pressure indicator litUsually simple to fixA named Triton lamp with one meaning: pressure fell below what the shower needs, so it cut power to the elements and left the water running.Related: water-supply
- Abnormal safety cut-out operatedGet it checkedTriton’s thermal cut-out is a one-shot device. It cannot be reset, and their own instruction is that an engineer replaces it after the fault is repaired.Related: same brand
- Water temperature cycling hot and coolGet it checkedTriton problem 3. The shower swings between hot and cool at intervals, and their published cause is the heater cycling on its temperature limiter.Related: same brand
- TP temperature protectionUsually simple to fixTriton’s automatic temperature protection. It removes power to the elements when the limit is exceeded and puts it back on its own once things cool.Related: same brand
- Shower fails to shut offGet it checkedTriton problem 7. Water keeps running after you press stop, and the shower is still an energised appliance while you work out what to do.Related: same brand
- Power on indicator not litGet it checkedThe neon in the start/stop button is a direct test of whether the supply has reached the shower. Unlit with the cord on points outward, not inward.Related: same brand
Own a Triton electric shower? Save it and its codes come first next time.
Related guides
Common questions
Do I need to do anything when it goes cold?
No. Triton’s published action is to wait until the water pressure resumes to normal, and their low pressure cut-out restores power to the elements automatically once it does.
How is this different from a shower that never gets hot?
Triton treat them as different problems. One that never heats points at the supply to the elements or the elements themselves. One that starts hot and goes cold is the pressure moving while you are in it.
Will a more powerful shower fix it?
No, and it may make it worse. The constraint is water arriving, not heat available — a higher-kW unit wants at least as much flow, so it hits the same threshold just as often.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.