Vaillant aroSTOR Twin Flue Kit 200L 270L | 20205775 | Single Wall

Description

The Vaillant aroSTOR twin flue kit (part no. 20205775) is an optional accessory that lets the air intake and air exhaust ducts of an aroSTOR VWL B 200/5 UK or 270/5 UK share one wall opening. Without it, a fully ducted installation needs two separate 160 mm openings, one for the intake and one for the exhaust.

Use it where wall space is limited, where you want a tidier external finish, or where the unit stands close to an outside wall. It is listed for both the 200 L and 270 L models, which share the same 160 mm air connections. The kit is not needed to install the cylinder; the unit also works with separate ducts, partly ducted, or unducted.

20205775

Vaillant part number

1 opening

Intake and exhaust share one wall hole

2 models

aroSTOR 200 L and 270 L

160 mm

Unit air connection size

10 m / 20 m

Max flexible / rigid duct, L1 + L2

Optional

Not required to install

Safety and regulatory

Never connect the aroSTOR to internal extract ducts, including bathrooms, shower rooms and kitchen extractors. Fit protective grilles or roof terminals on every duct opening so that water and foreign bodies cannot enter. Ducts must be insulated to prevent energy loss and condensation. All installation work must be done by a competent person following the aroSTOR installation manual and the instructions supplied with the kit.

Compatibility

For Vaillant aroSTOR VWL B 200/5 UK (article 0010024440) and VWL B 270/5 UK (article 0010028218) only. It is not intended for other Vaillant products. If the unit is ducted to outside (room-sealed) it must not be sited within 500 m of the coast. The unit's duct length limits still apply with the kit fitted, so count the kit and every elbow and grille in your run.

Key features

One wall opening

Routes the intake and exhaust through one penetration instead of two, which keeps the outside wall tidy and limits the number of openings to make good.

Made for the aroSTOR

A Vaillant accessory (20205775) listed for the 200 L and 270 L floor-standing models, which both use 160 mm air connections.

Suits fully ducted siting

In a fully ducted installation the air inlet and outlet are both in the external area, so the room is not cooled and its ventilation is not affected. Ideal for small utility and store rooms.

Optional, not essential

The cylinder installs with two separate ducts, one duct or none. Add the kit only when a single wall opening is the better answer for the site.

Works within the duct rules

Combined intake plus outlet length stays within 10 m flexible or 20 m rigid (plus two 90° elbows), using insulated 160 mm or larger ducts.

Prevents recirculation when planned correctly

The manual calls for a clearance of at least 220 mm between the ends of the air pipes in a fully ducted installation so that exhaust air is not drawn back in.

Planning the duct run

Duct rules from the aroSTOR installation manual

Maximum combined length of intake plus outlet (L1 + L2): 10 m flexible or 20 m rigid, in addition to two 90° elbows. In rigid runs, each elbow, attachment or mesh adds pressure loss equal to about 5 m of straight duct, so total them before you fix the route. Use insulated ducts of 160 mm or larger. Keep the air supply free of solvents, sprays, chlorinated cleaners and dust. Excess duct length or too many bends can cause frequent defrosting and low-pressure faults.

Check before you fix

Follow the instructions supplied with the kit for termination spacing and fixing, and confirm that the arrangement keeps exhaust air from being re-drawn into the intake. Confirm the termination meets the airflow and clearance needs for your site before cutting the wall opening.

Specification

Kit

Brand

Vaillant

Part number

20205775

Product type

Heat pump hot water cylinder air duct accessory (twin flue kit)

Function

Combines the air intake and exhaust ducts into one wall penetration

Compatible models

aroSTOR VWL B 200/5 UK (0010024440) and VWL B 270/5 UK (0010028218)

aroSTOR air connection and duct limits (from the manual)

Unit air connections

2 x 160 mm (inlet and outlet)

Duct type

Insulated, 160 mm or larger

Maximum combined length L1 + L2, flexible

10 m (plus two 90° elbows)

Maximum combined length L1 + L2, rigid

20 m (plus two 90° elbows)

Pressure loss allowance, rigid runs

About 5 m of straight duct per elbow, attachment or mesh

Nominal air flow

350 m³/h (minimum 320 m³/h)

Spacing between duct ends, fully ducted

At least 220 mm to prevent recirculation

Siting limit, room-sealed

Not within 500 m of the coast

Frequently asked questions

Do I need this kit to install an aroSTOR?

No. It is optional. The aroSTOR can be installed with two separate ducts, with one duct and the room as the other air path, or with no ducting. The kit is for when one wall opening suits the site better.

Is it compatible with both the 200 L and the 270 L?

Yes. It is listed for the aroSTOR VWL B 200/5 UK (article 0010024440) and the VWL B 270/5 UK (article 0010028218). Both models use 160 mm air connections. It is not intended for other Vaillant products.

What duct size and length can I use with it?

The aroSTOR needs insulated ducts of 160 mm or larger. The combined intake plus outlet length is limited to 10 m for flexible duct or 20 m for rigid duct, plus two 90° elbows. In rigid runs each elbow, attachment or mesh counts as about 5 m of straight duct.

Can I use it near the coast?

If the unit is ducted to outside (room-sealed), the manual says it must not be located within 500 m of any coastline. Check the site before you plan a fully ducted installation.

How do I stop the exhaust air being drawn back into the intake?

In a fully ducted installation the manual requires a clearance of at least 220 mm between the ends of the air pipes to prevent recirculation. Follow the kit's own instructions for spacing and fixing, and check the finished layout before commissioning.

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