Ariston
Ariston O-Ring Pump 998644
Ariston 998644 O-ring for the pump and automatic air vent on Microcombi, Microgenus, Microsystem and Excalibur boilers.
At a glance
- Part type: O-ring
- Also known as O-RING-PUMP, 1577222
Showing prices
£7.60
£6.33 ex. VAT · VAT at 20%
Available to order · 3 working days
Available to order · 3 working days
Not certain it's the right part? The technical team verifies fitment before dispatch — no charge, and it stops a second trip.Call the technical teamSend a technical question
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
The Ariston 998644 is a small rubber O-ring used as a sealing component on the pump and automatic air vent assembly of Ariston gas boilers. It forms the watertight joint between mating faces, preventing seepage and air ingress at the pump and vent connections. The part is listed by Ariston under the description O-RING - AUTOMATIC AIR VENT and is also catalogued as a pump O-ring.
Signs this part needs replacing
- Water weeping or a visible drip at the pump or automatic air vent joint
- Rust staining, scale trails or crusting around the O-ring seat
- The O-ring has hardened, flattened or cracked with age and no longer seals
- Air being drawn into the system, causing pump noise or repeated bleeding
- A joint that continues to seep after the housing has been re-tightened
Before you order
- Confirm the boiler model and serial number against the fitment list, as coverage is serial-number dependent
- Identify whether the failed seal is at the pump or the automatic air vent before ordering
- Check the mating faces and groove for damage or scale, as a worn seat will not seal with a new O-ring alone
- Verify the part number 998644 on the existing component or the manufacturer's parts list
Compliance
| Barcode / EAN | 5411692285920 |
|---|---|
| Alternative numbers | O-RING-PUMP, 1577222 |
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| ARISTON ARISTON MICROCOMBI 23 MFFI - FROM SERIAL No 2320018200001 TO SERIAL No 2320033400001 | — | — | — | |
| ARISTON ARISTON MICROCOMBI 23 MFFI - FROM SERIAL No 2320033400001 TO SERIAL No 2320101500001 | — | — | — | |
| ARISTON ARISTON MICROCOMBI 27 MFFI - EDITION ONE - FROM SERIAL No 2320309500001 | — | — | — | |
| ARISTON ARISTON MICROCOMBI 27MFFI - EDITION TWO - FROM SERIAL No 2320309500001 | — | — | — | |
| ARISTON ARISTON MICROGENUS 23 MFFI - FROM SERIAL No 2320005600001 TO SERIAL No 2320021400002 | — | — | — | |
| ARISTON ARISTON MICROGENUS 23 MMFI - LPG - FROM SERIAL No 2319932300018 TO SERIAL No 2320005600001 | — | — | — | |
| ARISTON ARISTON MICROGENUS 23 MMFI - NG - FROM SERIAL No 2319932300020 TO SERIAL No 2320005600001 | — | — | — | |
| ARISTON ARISTON MICROGENUS 27 MFFI - FROM SERIAL No 2320005600001 TO SERIAL No 2320021400002 | — | — | — | |
| ARISTON ARISTON MICROGENUS 27 MMFI - LPG - FROM SERIAL No 2319932400027 TO SERIAL No 2320005600001 | — | — | — | |
| ARISTON ARISTON MICROGENUS 27 MMFI - NG - FROM SERIAL No 2319932500011 TO SERIAL No 2320005600001 | — | — | — |
Showing 10 of 70 compatible appliances.
Fitment listings are a guide, not a guarantee. Plant-room assemblies get modified on site more often than not. Send us the GC number off the data badge and a photo of the existing valve and we will confirm before anything is dispatched.
Documents & drawings
Everything we hold for this part. Where a document exists but we don't hold it, the technical team will source it from the manufacturer — usually the same working day.
manual
ARISTON appliance manual — ECOSYSTEM 27 RFFI EDITION 2 LPG (SEPT 2004) (GC 41-116-08), ECOSYSTEM 27 RFFI EDITION 2 NG (SEPT 2004) (GC 41-116-08)
manualmanualARISTON appliance manual — MICROCOMBI 23 MFFI LPG EDITION 1 (OCT 2000) (GC 47-116-16), MICROCOMBI 23 MFFI LPG EDITION 2 (DEC 2000) (GC 47-116-16), MICROCOMBI 23 MFFI NG EDITION 1 (OCT 2000) (GC 47-116-16), MICROCOMBI 23 MFFI NG EDITION 2 (DEC 2000) (GC 47-116-16), MICROCOMBI 28 MFFI LPG EDITION 1 (APR 2003) (GC 47-116-24), MICROCOMBI 28 MFFI NG EDITION 1 (APR 2003) (GC 47-116-24)
manualmanualARISTON appliance manual — MICROGENUS 23 MFFI LPG EDITION 1 (DEC 1999) (GC 47-116-14), MICROGENUS 23 MFFI LPG EDITION 2 (APR 2000) (GC 47-116-14), MICROGENUS 23 MFFI LPG EDITION 5 (MAR 2004) (GC 47-116-14), MICROGENUS 23 MFFI NG EDITION 1 (DEC 1999) (GC 47-116-14), MICROGENUS 23 MFFI NG EDITION 2 (APR 2000) (GC 47-116-14), MICROGENUS 23 MFFI NG EDITION 5 (MAR 2004) (GC 47-116-14), MICROGENUS 27 MFFI LPG EDITION 1 (DEC 1999) (GC 47-116-15), MICROGENUS 27 MFFI LPG EDITION 2 (APR 2000) (GC 47-116-15), MICROGENUS 27 MFFI LPG EDITION 5 (MAR 2004) (GC 47-116-15), MICROGENUS 27 MFFI NG EDITION 1 (DEC 1999) (GC 47-116-15), MICROGENUS 27 MFFI NG EDITION 2 (APR 2000) (GC 47-116-15), MICROGENUS 27 MFFI NG EDITION 5 (MAR 2004) (GC 47-116-15)
manualmanualARISTON appliance manual — MICROSYSTEM 10 RFFI LPG EDITION 1 (AUG 2000) (GC 41-116-04), MICROSYSTEM 10 RFFI LPG EDITION 3 (FEB 2004) (GC 41-116-04), MICROSYSTEM 10 RFFI LPG EDITION 4 (SEPT 2004) (GC 41-116-04), MICROSYSTEM 10 RFFI NG EDITION 1 (AUG 2000) (GC 41-116-04), MICROSYSTEM 10 RFFI NG EDITION 3 (FEB 2004) (GC 41-116-04), MICROSYSTEM 10 RFFI NG EDITION 4 (SEPT 2004) (GC 41-116-04)
manualmanualARISTON appliance manual — MICROSYSTEM 15 RFFI LPG EDITION 1 (AUG 2000) (GC 41-116-05), MICROSYSTEM 15 RFFI LPG EDITION 3 (FEB 2004) (GC 41-116-05), MICROSYSTEM 15 RFFI LPG EDITION 4 (SEPT 2004) (GC 41-116-05), MICROSYSTEM 15 RFFI NG EDITION 1 (AUG 2000) (GC 41-116-05), MICROSYSTEM 15 RFFI NG EDITION 3 (FEB 2004) (GC 41-116-05), MICROSYSTEM 15 RFFI NG EDITION 4 (SEPT 2004) (GC 41-116-05)
manualmanualARISTON appliance manual — MICROSYSTEM 21 RFFI LPG EDITION 1 (AUG 2000) (GC 41-116-06), MICROSYSTEM 21 RFFI LPG EDITION 2 (JAN 2004) (GC 41-116-06), MICROSYSTEM 21 RFFI LPG EDITION 3 (SEPT 2004) (GC 41-116-06), MICROSYSTEM 21 RFFI NG EDITION 1 (AUG 2000) (GC 41-116-06), MICROSYSTEM 21 RFFI NG EDITION 2 (JAN 2004) (GC 41-116-06), MICROSYSTEM 21 RFFI NG EDITION 3 (SEPT 2004) (GC 41-116-06), MICROSYSTEM 28 RFFI LPG EDITION 1 (AUG 2000) (GC 41-116-07), MICROSYSTEM 28 RFFI LPG EDITION 2 (JAN 2004) (GC 41-116-07), MICROSYSTEM 28 RFFI LPG EDITION 3 (SEPT 2004) (GC 41-116-07), MICROSYSTEM 28 RFFI NG EDITION 1 (AUG 2000) (GC 41-116-07), MICROSYSTEM 28 RFFI NG EDITION 2 (JAN 2004) (GC 41-116-07), MICROSYSTEM 28 RFFI NG EDITION 3 (SEPT 2004) (GC 41-116-07)
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