Redring Shower cycles from HOT to COLDwhat to check
Redring name one cause: the temperature is set too high, so the thermal cut-out keeps operating. Their fix is a dial adjustment done slowly.
Take care
What this means
Redring treat this as the first entry in their self-help list and they attribute it to a single cause, which is unusual candour for a troubleshooting table. Their wording is that the shower temperature is set too hot, causing the thermal cut-out safety device to operate. What is happening is a loop rather than a fault: the setting asks for more heat than the flow can carry away, the temperature inside rises to the threshold, the cut-out takes the elements out of circuit, the water goes cold, everything cools, the elements come back and the cycle starts again. The shower is not failing to hold a temperature so much as repeatedly bumping into its own ceiling.
The remedy Redring publish is a specific two-stage dial procedure and it is worth following literally rather than approximating. Turn the knob anticlockwise towards the low-numbered end to increase the water flow. Then increase the temperature slowly, clockwise towards the high end, until you reach a comfortable showering temperature. And crucially: wait about twenty seconds after each adjustment for it to affect the water. That interval is the part people skip, and skipping it is why the procedure fails for them — they turn the dial, feel nothing change within a couple of seconds, turn it further, and end up back at a setting that trips the cut-out again.
Redring add one further option for when the procedure alone is not enough, which is that the economy setting may need to be selected. Fewer elements running means less heat into the same flow, and it moves the shower away from its threshold rather than balancing on it.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Temperature set too high for the available flow | Redring’s single published cause. The setting asks for more heat than the water can carry away, so the cut-out operates repeatedly. | Common |
| Adjustments made too quickly to take effect | Redring specify twenty to thirty seconds per adjustment. Turning further before the previous change arrives is how people end up back at the same setting. | Common |
| Power setting too high for the season | Redring name economy as an option. Warmer incoming mains means the same number of elements delivers more heat than it did in winter. | Occasional |
| Restricted flow reducing the margin | A scaled head or filter leaves less flow to absorb the heat, so a setting that was fine last year now reaches the threshold. | Occasional |
What to try yourself
Turn the temperature knob anticlockwise towards the low-numbered end to increase the water flow, which is the first half of Redring’s published procedure.
Wait twenty to thirty seconds. Redring are explicit that each adjustment takes that long to affect the water, and this is the step people skip.
Increase the temperature slowly, clockwise, waiting twenty to thirty seconds after each small movement, until you reach a comfortable showering temperature.
If it still cycles, select the economy setting. Redring name this as the additional option, and fewer elements means less heat going into the same flow.
Clean or replace the showerhead if the flow looks weak. Recovering flow raises the margin between your setting and the cut-out threshold.
Isolate the shower at the pull cord before removing anything from the water path.
Get a qualified electrician to look at your Redring 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–£60
Time on site
15 minutes
Nothing. Redring answer this entirely within self help, and the only likely cost is a replacement showerhead if flow turns out to be the underlying limit.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
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Related Redring fault codes
- otGet it checkedOver Temperature Shutdown on a Selectronic: the water got too hot, so the shower stopped it. Purge it cold before restarting, and stop using the isolator to switch off.Related: overheat
- Water too HOTGet it checkedRedring give six checks, and the one that distinguishes them is a filter inside the solenoid valve that other brands do not send you to.Related: overheat
- Heating after switch-offStop — call an engineerA Selectronic that has been stopped with the Start/Stop button but can still be heard heating has lost control of its elements. Redring’s answer is a new triac board; yours is the isolator.Related: overheat
- Water too COLDGet it checkedRedring answer this with eight checks in a deliberate order, and the seventh is the one nobody guesses: run the shower cold to reset the cut-out.Related: same brand
- Water dripping from the bottom of the showerGet it checkedRedring attribute this to the safety pressure relief having operated, and they are clear it is a replacement part rather than something that reseals.Related: same brand
- LPGet it checkedLP on a Selectronic Advanced means the water supply has dropped below two litres a minute. The shower has cut its heaters rather than boil a trickle.Related: same brand
Own a Redring electric shower? Save it and its codes come first next time.
Related guides
Common questions
Is the shower broken if it cycles between hot and cold?
Redring do not treat it as a breakage — they file it under self help with a single cause, the temperature being set too hot, and answer it with a dial procedure rather than a repair.
Why does turning the knob one way increase the flow?
Because on these units the control is a flow valve rather than a thermostat. Redring’s procedure turns it anticlockwise towards the low numbers to increase flow, then brings the temperature back up gradually.
What does the economy setting actually do?
It runs fewer heating elements, so less heat goes into the same amount of water. In warmer months, or where flow is limited, it keeps the shower comfortably below the temperature that triggers the cut-out.
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.