Alpha Grommet 21 D 1.6407

Sealing grommet 21 D for Alpha gas boilers, part number 1.6407.

At a glance

Also known as GROMMET-21-D, 1250417

Manufacturer part no.

1.6407

Showing prices

£5.00

£4.17 ex. VAT · VAT at 20%

Available to order · 7 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 team Send 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 Alpha Grommet 21 D is a sealing grommet used on Alpha gas boilers. It sits at pipe or cable entry points through the appliance casing, protecting the opening and maintaining a seal. It is supplied under part number 1.6407.

Signs this part needs replacing

Rubber is cracked, split or perished
Grommet has hardened and no longer seals against the casing
Grommet is missing or has become dislodged
Visible gaps around pipe or cable entries
Signs of air or gas leakage at the entry point

Before you order

Confirm your boiler model matches the fitment listed above
Check the existing grommet for the 21 D marking
Verify part number 1.6407 against your appliance's parts list

Can't find yours? Call 01302 279234

Make	Model / assembly	Reference	Years	Fitment
ALPHA CB50	47-532-18	`47-532-18`	—	—
ALPHA CB50 (LPG)	—		—	—

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.

Not sure which part?

Search by part number, product name or brand — our technical team confirms fitment before anything is dispatched.

Send a technical question Call the technical team