Worcester Greenstar 4000 21kW System - Boiler Only

Worcester Greenstar 4000 21kW System - Boiler Only

£1,470.00 -Incl. VAT
£1,225.00 - Excl. VAT
In stock

Greenstar 4000 System Boiler 21KW, Built on all the tried, tested, and much-loved features of the Greenstar i, the Greenstar 4000 is instantly familiar and yet totally transformed in appearance, performance, and installer plus points.

With outputs of 12kW to 24kW, Greenstar raised the bar with the speed and ease of installation, commissioning, and servicing.

Encompassing features from the range-topping 8000 Style, informed by insights from installers and featuring real advances in siting flexibility, it takes what was the nation’s favorite boiler and makes it even better.

The entire gas boiler range is able to run on a 20% hydrogen blend - so the customer can be confident it will run on gas for its lifetime.

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Returns Policy

You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the 'Complete Orders' link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.


We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.

When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.

Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.