Biasi Parva HE Combi Fault codes & diagnostics

10 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

Combi Gas

The Parva HE range comes in 2 types

Pick the one you have. The fault codes, GC numbers and manual differ by type.

Each model has its own manual A family spans several manuals, one per model or generation. Pick your model above and its page has the manual its fault codes were read from.

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Severity at a glance

Each cell = one fault code. Hover to identify.
2 Emergency 5 High 3 Medium

All 10 documented codes

Tap any card for details

Faulty air pressure switch

Your boiler has stopped working because it cannot safely confirm that exhaust gases are clearing properly.

High Engineer only £100-200 Shared across the Parva HE Combi range

Parts commonly replaced

  • Air pressure switch
  • Pressure switch silicone tubes
  • Flue terminal

Related codes

Faulty c.h. temperature probe NTC

Your boiler's heating temperature sensor has failed, which means the system cannot accurately measure how hot the water is getting.

Medium Engineer only £90-160 Shared across the Parva HE Combi range

Parts commonly replaced

  • Central Heating NTC Temperature Sensor
  • Wiring Harness

Related codes

Faulty d.h.w temperature probe NTC

Your boiler is struggling to accurately measure the temperature of your hot water because a sensor is faulty.

Medium Engineer only £90-160 Shared across the Parva HE Combi range

Parts commonly replaced

  • DHW NTC Temperature Sensor
Faulty flue temperature probe NTC

Your boiler has detected an issue with the sensor that measures the temperature of the exhaust gases leaving the flue.

Medium Engineer only £120-250 Shared across the Parva HE Combi range

Parts commonly replaced

  • Flue NTC temperature sensor
  • Wiring harness
Faulty primary circuit

Your boiler has detected that water isn't flowing properly through its internal heating pipes, so it has safely shut down to prevent damage.

High Engineer only £150-350 Shared across the Parva HE Combi range

Parts commonly replaced

  • Circulating pump
  • Automatic bypass valve
  • Plate heat exchanger

Related codes

Flue temperature probe NTC lockout

Your boiler has safely shut down because a sensor detected that the temperature of the exhaust gases leaving through the flue is too high.

Emergency Engineer only £120-250 Shared across the Parva HE Combi range

Parts commonly replaced

  • Flue NTC temperature sensor
  • Wiring harness

Related codes

Lack of burner ignition

Your boiler is trying to start up, but it is failing to light the flame safely.

High Engineer only £150-300 Shared across the Parva HE Combi range

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed Circuit Board (PCB)

Related codes

Safety thermostat lockout

Your boiler has shut itself down safely because it detected that internal temperatures became too high.

High Engineer only £150-300 Shared across the Parva HE Combi range

Parts commonly replaced

  • Safety thermostat
  • NTC thermistor
  • Automatic bypass valve
  • Circulating pump

Related codes

Avoid the next call-out bill

Monthly cover means no unexpected bills when your boiler breaks down.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.