Ideal Pump Dry Run fault codewhat it means and how to fix it
A Logic+ or Logic Max text screen saying the pump is turning with no water to move. Ideal's steps are the filling ones: boiler off and cold, fill to 1.0 bar, bleed the radiators, refill.
Take care
What Pump Dry Run means
Pump Dry Run appears in the 2023 user guides for the Logic+ and Logic Max Combi2 and System2, the text-screen versions of the boiler the plain Logic Combi2 reports in three-character codes. The modulating pump on those boilers can tell when its impeller is spinning in air rather than water and says so, and Ideal give the householder the same three steps they give for Low Water Pressure and No Water Flow: with the boiler off and the system cold, fill to 1.0 bar; bleed the radiators and refill to 1.0 bar; if the fault persists, contact the installer.
The screen offers only a Menu key, no Restart, which is Ideal's way of saying it clears itself once the pump is wet again. The heat-only Heat2 guides do not list it because that boiler has no pump of its own.
What Ideal do not publish is which of the Logic Combi2's numeric pump codes — F 12 for a blocked rotor, F 13, F 15 and F 17 for pump faults — this message corresponds to, if any, so it stands as its own page rather than being folded into one of them.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| System pressure lost | The commonest way a pump ends up in air. A slow leak or a discharged expansion vessel lets the level fall until the pump chamber, at the top of the boiler, empties first. | Common |
| Air trapped after filling | A system refilled quickly leaves a pocket in the pump housing that the pressure gauge cannot see. Ideal's bleed-and-refill step exists for exactly this. | Common |
| Pump reporting wrongly | A pump that is wet and still says it is dry has a fault of its own, and that is the installer's end of Ideal's three steps. | Rare |
What to try yourself
Switch the boiler off and let it go cold. Read the pressure gauge: if it is below 1.0 bar, fill using the filling loop until it reads 1.0 bar, then close the loop. Ideal's user guide gives these as the first steps.
Bleed every radiator, starting downstairs, then refill to 1.0 bar. Bleeding drops the pressure, and a pump housing full of air will only clear once the system is properly vented and back at pressure.
Switch on and call for heat. The message has no Restart key because it clears on its own once the pump sees water. If it stays, or comes back within days, contact the installer — the pump may be at fault, or the system is losing water.
Get a Gas Safe registered engineer to look at your Ideal Pump Dry Run
We do not pass enquiries to a repair firm, so there is no form here. Find a Gas Safe registered engineer through the Gas Safe Register, and ask to see their registration card when they arrive — it is the register, not the van, that tells you they are qualified.
What it costs to fix
Typical repair cost
£0–£380
Time on site
30 minutes
Nothing if filling and bleeding cures it. Finding a leak that keeps emptying the system is £80–£150 upwards depending on where it is. A replacement modulating pump £220–£380 fitted.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Parts you may need
We may earn a commission if you buy a part through one of these links. It does not change what you pay, and it does not affect which parts we list.
Expansion vessel (8 litre, sealed system)
EV-8L£35–£85Plumbing merchant
Price checked 28 September 2026
Central heating circulating pump
CH-PUMP-15-60£90–£180Plumbing merchant
Price checked 28 September 2026
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Ideal fault codes
- L1Get it checkedThe boiler is not seeing enough water flow through it to run safely, so it has stopped. Usually a pump, an air lock, or a blocked filter.Related: overheat and circulation
- FDGet it checkedNo water flow has been detected. The pump is the prime suspect and this will become an overheat if it is left.Related: overheat and circulation
- L3Get it checkedThe boiler has stopped because it cannot detect water moving through it. Ideal's own steps are to fill the system to 1 bar with it cold, bleed the radiators and try again.Related: overheat and circulation
- L AGet it checkedThe overheat thermostat on an Isar, Icos, Mexico HE or Esprit has tripped and the boiler has locked out. Ideal say hold reset for two seconds; if it recurs, switch off and call the installer.Related: overheat and circulation
- FUGet it checkedThe water leaving the boiler is more than 50°C hotter than the water coming back, which means very little of it is moving. Check the valves are open before anyone condemns the pump.Related: overheat and circulation
- F12Get it checkedThe pump rotor is jammed. Ideal's remedy is to clear the blockage — on a modern Logic that is an engineer freeing or replacing a sealed pump head, not a screwdriver in a bleed screw.Related: overheat and circulation
Own an Ideal boiler? Save it and its codes come first next time.
Related guides
Common questions about Ideal Pump Dry Run
Why does the screen have no Restart button for this?
Because it is not a lockout. Ideal only offer Restart on faults that latch, like Ignition Lockout. Pump Dry Run is a condition the boiler reports while it lasts and drops when the pump is wet again, so the fix is filling, not pressing.
Is this the same as No Water Flow?
They overlap but are not the same. No Water Flow means the boiler cannot detect water moving; Pump Dry Run means the pump itself has detected it is running in air. Ideal give the same filling steps for both, and both point at pressure and air before anything else.
Which code is this on a plain Logic Combi2?
Ideal do not say. The Combi2 has F 12 for a blocked rotor and F 13, F 15 and F 17 as pump faults, but no published mapping from Pump Dry Run to any of them, so this page does not claim one.
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.