comtherm.co.uk — AI Site Grade

Analysis

The Audit: comtherm.co.uk

The live site is entirely invisible to every AI crawler — and to browsers — because Cloudflare's JS challenge wall blocks all unauthenticated requests at the edge, returning a 403 "Verify your connection" page with zero real content.

Crawler Access

Every AI bot tested — GPTBot, ClaudeBot, PerplexityBot, Google-Extended, OAI-SearchBot, ChatGPT-User, Bytespider, Applebot-Extended, anthropic-ai, Perplexity-User — receives a 403 from Cloudflare's managed challenge platform. The robots.txt and llms.txt endpoints also return 403 (Cloudflare JS challenge HTML, not actual files). The sitemap.xml is unreachable. The site runs on Shopify (evidenced by the cdn.shopify.com asset URLs in the Wayback snapshot, the OnlineStore schema type, and the myshopify.com-style URL patterns), fronted by Cloudflare. There is no bypass path: the Cloudflare challenge requires JavaScript execution and cookie acceptance, which no AI crawler performs.

Cold-Knowledge Gap

The LLM's cold knowledge describes ComTherm as a UK manufacturer of underfloor heating controls — programmable thermostats, wiring centres, manifold actuators. This is entirely wrong. The actual site (visible only via Wayback Machine snapshots) reveals Comtherm Ltd is an industrial combustion equipment manufacturer founded in 1974, designing and building industrial process burners, package burners, and engineered combustion systems for sectors including automotive paint finishing, food processing, paper drying, and metal treatment. The LLM has confused the brand with a completely different product category.

Content & Schema Posture

The Wayback-visible homepage carries rich JSON-LD schema: OnlineStore, WebSite, Organization, BreadcrumbList, WebPage, and ImageObject — all correctly structured with address, contact point, telephone, and social profiles. The schema declares the business as an OnlineStore at "Comenco Works, Union Lane, Droitwich, WR9 9AZ." The site has well-structured content: product categories (EK, FC, IL, PC, PH, PP, RSP, SP, TF, TFR, TFR-HT burner series), a blog with case studies from 2022–2025, and a spares shop with 30+ component categories. None of this is accessible to AI crawlers live.

External Signals

The brand has near-zero external web footprint. Searches for "Comtherm," "Comtherm Ltd," "Comtherm burner Droitwich," and "comtherm.co.uk" return zero results across multiple search engines. The schema lists Facebook, Twitter, and LinkedIn profiles, but none appear indexed or discoverable. No reviews, forum threads, press mentions, or directory listings surfaced. The only accessible record of the company's existence is the Wayback Machine snapshot from November 2025 and the DNS records (A record at 23.227.38.65 — a Shopify IP, MX via livemail.co.uk).

Findings

1. Cloudflare JS challenge wall blocks all AI crawlers High

   Every AI bot tested receives a 403 response from Cloudflare's managed challenge platform, which requires JavaScript execution and cookie acceptance that no AI crawler performs.

   What to change: Configure Cloudflare to allow AI crawler user agents (e.g., GPTBot, ClaudeBot) through the JS challenge, or serve a static version of the site to bots.

2. Robots.txt and llms.txt endpoints return 403 High

   The robots.txt and llms.txt endpoints return Cloudflare JS challenge HTML instead of actual files, making it impossible for crawlers to discover allowed paths.

   What to change: Ensure robots.txt and llms.txt are served without Cloudflare challenge, or bypass the challenge for these paths.

3. Sitemap.xml is unreachable High

   The sitemap.xml endpoint returns a 403, preventing crawlers from discovering the site's URL structure.

   What to change: Serve sitemap.xml without Cloudflare challenge, or bypass the challenge for this path.

4. Near-zero external web footprint High

   Searches for the brand name, domain, and related terms return zero results across multiple search engines. No reviews, forum threads, press mentions, or directory listings were found.

   What to change: Build external signals through directory listings, press releases, industry forums, and social media engagement.

5. LLM cold knowledge misidentifies product category High

   LLM cold knowledge describes ComTherm as a manufacturer of underfloor heating controls, but the actual site (via Wayback) shows it produces industrial combustion equipment.

   What to change: Publish authoritative content (e.g., Wikipedia, industry directories) to correct the LLM's knowledge.

6. No pages indexed in search engines High

   The site:comtherm.co.uk search returns zero results, indicating no pages are indexed by search engines.

   What to change: Ensure the site is accessible to search engine crawlers by adjusting Cloudflare settings and submitting a sitemap to Google Search Console.

7. Social profiles listed in schema are not discoverable Medium

   The schema lists Facebook, Twitter, and LinkedIn profiles, but none appear indexed or discoverable via search.

   What to change: Verify and update social media profiles, ensure they are public and linked from the site.

8. No llms.txt file for AI crawler guidance Medium

   The llms.txt endpoint returns a 403, and no llms.txt file is served, missing an opportunity to guide AI crawlers to key content.

   What to change: Create and serve an llms.txt file listing important pages for AI crawlers.

9. No known URLs discovered via crawling Medium

   The list_known_urls tool returned zero URLs, indicating no public crawl data exists for the domain.

   What to change: Ensure the site is crawlable and indexed by search engines to build a URL inventory.

What's working

• Rich JSON-LD schema on homepage — The Wayback snapshot shows the homepage includes comprehensive JSON-LD schema (OnlineStore, WebSite, Organization, etc.) with correct business details.
• Well-structured content visible in Wayback — The site has organized product categories, a blog with case studies, and a spares shop with 30+ component categories, all properly structured.
• Correct business address in schema — The Organization schema includes a valid physical address (Comenco Works, Union Lane, Droitwich) and contact details.
• Wayback Machine snapshot available — A recent Wayback Machine snapshot (November 2025) preserves the site's content, providing a fallback for historical reference.