Baxi E193 fault codewhat it means and how to fix it
Pre-circulation fault on the selector-switch Baxis (Duo-tec Combi HE, Platinum, Megaflo HE A), shown as E1 then 93. Baxi offer no reset for it; the pump or air is the cause.
Take care
Get a Gas Safe registered engineer to look at your Baxi E193
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 E193 means
E193 is the last entry in the ten-code table Baxi printed for the Duo-tec Combi HE A, Platinum Combi, Platinum+ and Megaflo System HE A: "Pre-Circulation Fault". On these boilers the facia shows it as "E1" alternating with "93". The board runs the pump before it will spark and expects the flow temperature to shift by a degree or so as water moves through the heat exchanger; no shift, no ignition, and E193 is shown instead.
The installation manuals put it beside E125 in the fault-finding flowchart — "Error E125 or E193 flashing: ensure that primary circulation is OK and that there is no blockage" — and list the circulation checks: pump running, system vented, diverter valve open to the heating circuit. Unlike E110, E130 and E133, Baxi do not offer the selector-switch reset for E193 on this generation. The user guide's instruction for the component codes is to note the code and contact your installer or service engineer.
In practice E193 on a Duo-tec HE that has sat idle over summer is very often a pump that has stuck and will free itself once an engineer spins it, or air in the pump housing after a top-up; on a boiler that has been running fine it is more often a pump that is genuinely failing or a system that has sludged. Boilers with the digital display and Reset button report the same test as E109 and do allow a panel reset, which is why the two numbers have separate pages.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Pump stuck or failed | Common on a Duo-tec HE after a summer without heating. The pump hums but the rotor does not turn, and the pre-circulation test sees no movement. The manual's flow checks 230 V to the pump first. | Common |
| Air in the pump or heat exchanger | After a repressurise or radiator work, air collects at the pump and stops it moving water. Baxi's flow: ensure primary circulation is OK and the system is vented. | Common |
| Blockage in the primary circuit | The flowchart's second clause, "that there is no blockage". Sludge in the heat exchanger or a filter that has not been cleaned in years. | Occasional |
| Flow sensor not in contact | A sensor that has slipped out of its pocket cannot see the temperature change the test relies on, and the board reports no circulation on a system that is circulating. | Rare |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£80–£320
Time on site
45 minutes
Venting and a pump check within a call-out, £80–£120. Pump £180–£320 fitted. System clean £300–£500 if sludged.
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.
Magnetic system filter, 22mm
MAG-22£65–£120Plumbing merchant
Price checked 28 September 2026
Baxi / Potterton / Main NTC temperature sensor (flow, return or DHW)
7207471£18–£45Authorised Baxi parts distributor
Price checked 28 September 2026
Baxi / Potterton / Main pump assembly
7684006£120–£240Authorised Baxi parts distributor
Price checked 28 September 2026
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Related Baxi fault codes
- E110Stop — call an engineerThe safety thermostat has tripped on overheat — "overheat of the primary water" in Baxi's words. One reset is allowed on every generation. If it trips again, the water is not moving.Related: overheat and circulation
- E125Get it checkedBaxi's primary circulation fault, decided by two temperature tests the manuals spell out. Pump, air or a blocked filter; the pressure is usually fine.Related: overheat and circulation
- E.04.08Stop — call an engineer"Maximum safe temperature value reached": the safety thermostat has opened on a Baxi 200/400 Combi or Combi 2. Circulation first, the thermostat second, in Baxi's own order. One reset, then an engineer.Related: overheat and circulation
- E.01.17Get it checked"No water circulation (permanent)" on the Baxi 200/400 Combi and Combi 2, after H.01.18 has shown as a temporary block. Pressure, venting and the pump, in Baxi's order; reset once.Related: overheat and circulation
- E109Get it checkedPre-circulation fault on the digital-display Baxis: the board could not confirm water moving before it would light the burner. Vent the system; Baxi allow a reset from the button.Related: overheat and circulation
- E270Get it checkedBaxi's dry-fire circulation fault: the heat exchanger was heating with too little water passing through it. Air, a stopped pump or a closed circuit; not a code to reset repeatedly.Related: overheat and circulation
Own a Baxi boiler? Save it and its codes come first next time.
Related guides
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.