Ferroli
Ferroli By-Pass Valve 39846120
By-pass valve 39846120 for Ferroli Modena, Twist PRO and T-ONE gas boilers, maintaining minimum primary circuit flow.
At a glance
- Also known as 3510259
£25.96
£21.63 ex. VAT · VAT at 20%
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
The Ferroli 39846120 is a by-pass valve used in Ferroli gas boilers. It sits in the primary circuit and maintains a minimum flow rate through the heat exchanger when system demand falls, such as when thermostatic radiator valves close down. It is listed in the Ferroli gas boiler spares range under isolation valves.
Signs this part needs replacing
- Boiler short-cycling or frequent burner lockouts
- Overheating or a high temperature differential across the primary circuit
- Noise from the valve or pipework when heating demand changes
- Water weeping or staining around the valve body
- Poor heating or hot water performance at low system demand
Before you order
- Confirm your boiler model and GC number against the fitment list
- Check the part number on the existing valve matches 39846120
- Confirm whether your appliance is natural gas or LPG
- Check the appliance serial or date code where a model has multiple build references
Compliance
| Alternative numbers | 3510259 |
|---|
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| FERROLI FERROLI MODENA HE 27C | — | — | — | |
| FERROLI FERROLI MODENA HE 32C | — | — | — | |
| FERROLI FERROLI T-ONE 25C | — | — | — | |
| FERROLI FERROLI T-ONE 30C | — | — | — | |
| FERROLI MODENA 25C HE NG | 47-267-58 | 47-267-58 | — | — |
| FERROLI MODENA 27C HE LPG - 30K1045001 (09/07/2012) | 47-267-57 | 47-267-57 | — | — |
| FERROLI MODENA 27C HE LPG - 30K1045003 (01/12/2013) | 47-267-57 | 47-267-57 | — | — |
| FERROLI MODENA 27C HE NG - 30K1045001 (09/07/2012) | 47-267-57 | 47-267-57 | — | — |
| FERROLI MODENA 27C HE NG - 30K1045003 (01/12/2013) | 47-267-57 | 47-267-57 | — | — |
| FERROLI MODENA 30C HE NG | 47-267-56 | 47-267-56 | — | — |
Showing 10 of 20 compatible appliances.
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.
FERROLI appliance manual — MODENA 25C HE NG (GC 47-267-58), MODENA 27C HE LPG - 30K1045001 (09/07/2012) (GC 47-267-57), MODENA 27C HE LPG - 30K1045003 (01/12/2013) (GC 47-267-57), MODENA 27C HE NG - 30K1045001 (09/07/2012) (GC 47-267-57), MODENA 27C HE NG - 30K1045003 (01/12/2013) (GC 47-267-57), MODENA 30C HE NG (GC 47-267-56), MODENA 32C HE LPG - 30K1045001 (09/07/2012) (GC 47-267-55), MODENA 32C HE LPG - 30K1045003 (01/12/2013) (GC 47-267-55), MODENA 32C HE NG - 30K1045001 (09/07/2012) (GC 47-267-55), MODENA 32C HE NG - 30K1045003 (01/12/2013) (GC 47-267-55)
manualmanualFERROLI appliance manual — T-ONE 25C HE (GC 47-267-59), T-ONE 30C HE (GC 47-267-60)
manualNo technical questions yet for this part.
Not sure which part?
Search by part number, product name or brand — our technical team confirms fitment before anything is dispatched.