WarmZilla vs BOXT: The Battle of the Online Giants
By David Evans | Senior Heating Analyst | Updated: January 2026
At a Glance
Verified Analysis
If you are looking to buy a boiler online, you have likely narrowed it down to WarmZilla and BOXT. Both companies are excellent. Both will beat any like-for-like quote by £50. And both offer next-day installation.
So how do you choose? It comes down to one key difference: Expertise vs. Logistics.
The Head-to-Head Data
We compared a standard installation for a Worcester Bosch Greenstar 4000 (the UK’s most popular mid-range boiler) to see exactly where your money goes.
|
Feature |
WarmZilla |
British Gas |
|---|---|---|
|
Company Type |
Engineer-Founded |
Tech / Logistics Retailer |
|
Boiler Choice |
Wide Range |
Worcester Bosch Focus |
|
Price Guarantee |
10 Years (Included) |
Price Match Promise (Beats quotes by £50) |
|
Install Speed |
24 – 48 Hours |
24 – 48 Hours |
|
Verdict |
WINNER |
Runner Up |
1. The Expertise Gap
This is where the companies split. BOXT is effectively a logistics machine—efficient, slick, and fast. It feels like buying from an online shop.
WarmZilla was built by heating engineers. Their process is designed to catch technical issues before the installer arrives. Because their support team has trade experience, they can often guide you to a better boiler for your specific home setup, rather than just the best-seller.
2. The Pricing Deadlock
In terms of aggressive pricing, it is a draw. Both companies have a “Beat any Quote by £50” policy for like-for-like swaps.
The Hidden Difference: While the guarantee is the same, the starting price often isn’t. BOXT pushes premium Worcester Bosch boilers heavily. WarmZilla offers a wider range of budget-friendly brands like Vokera and Alpha.
If you just want a working boiler for the lowest possible price, WarmZilla’s wider selection usually means a lower entry point.
WarmZilla
BOXT
Is the price quoted truly fixed?
Yes. Both WarmZilla and BOXT use advanced quoting algorithms to provide a fixed price instantly. Provided the details you submit about your current system are accurate and you provide the necessary photos for the engineers to review, the price quoted is the price you pay. There are no hidden extras for standard installations.
Who has the better price guarantee?
WarmZilla typically offers a “Best Price Guarantee” where they aim to beat any like-for-like quote by £50. BOXT also operates a price match policy. To qualify for either, the competing quote must usually come from a national installer and be for the same boiler model with identical warranty terms and installation extras.
Can I really get my boiler installed tomorrow?
In many cases, yes. Both providers offer next-day installation across the majority of the UK. This is subject to engineer availability in your specific postcode and requires you to complete your order and pass the technical photo check before the mid-afternoon cut-off point.
What happens if I have an issue after the installation?
Both companies pride themselves on aftercare. Because your boiler comes with a manufacturer’s warranty (often 10 – 12 years), any faults with the unit itself are covered by the manufacturer. If there is an issue with the installation work, both providers have support teams and local engineers who can be dispatched to rectify the problem.
Do these companies use their own engineers?
BOXT and WarmZilla both utilise a vast network of subcontracted Gas Safe registered engineers. These engineers are vetted to ensure they meet high standards of workmanship. This decentralized model is what allows both companies to offer such rapid installation times nationwide.