Knebworth: plumbing, heating and air-conditioning companies
Knebworth has 2 plumbing, heating and air-conditioning companies (SIC 43220) and 14 electrical and other installation companies registered here (Companies House, 1 Sep 2026); 0 are MCS-certified for air-to-air yet. If the office is in SG3, summer 2026 had ≈11 nights above 18 °C there (7 times the 1991–2020 average of 1.5).
SIC 43220
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BOILERGEEKS 24/7 LTD, incorporated 2013, status Active.
Plumbing, heating and air-conditioning companies
| Company | Incorporated | Status | District |
|---|---|---|---|
| BOILERGEEKS 24/7 LTD | 2013 | Active | SG3 |
| INNOVATIVE VENTILATION SOLUTIONS LIMITED | 2019 | Active | SG3 |
Electrical and other installation companies
| Company | SIC | Incorporated | Status | District |
|---|---|---|---|---|
| MAXX WATTAGE ELECTRICALS LTD | 43210 · electrical installation; 33140 | 2024 | Active | SG3 |
| TAW EXTERNAL INSULATION & RENDERING LTD | 43290 · other construction installation | 2021 | Active | SG3 |
| PELMAN & CO LTD | 43210 · electrical installation; 41201; 41202; 95220 | 2020 | Active | SG3 |
| ROBINZ LTD | 43210 · electrical installation; 47910 | 2023 | Active | SG3 |
| BALDOCK INDUSTRIAL RECOVERY LTD | 43290 · other construction installation | 2023 | Active | SG3 |
| SWIFT BUILD CONTRACTORS LIMITED | 43290 · other construction installation; 41201; 41202 | 2025 | Active | SG3 |
| AVELEX ELECTRICAL LTD | 43210 · electrical installation | 2011 | Active | SG3 |
| ABP ELECTRICAL LTD | 43210 · electrical installation | 2022 | Active | SG3 |
| ACCESS DOOR SERVICES LIMITED | 43290 · other construction installation | 2003 | Active | SG3 |
| DC ELECTRIX LTD | 43210 · electrical installation | 2024 | Active | SG3 |
| ASQ SUN SALUTE LTD | 43210 · electrical installation | 2025 | Active | SG3 |
| SMART VENTILATION SYSTEMS LTD | 43290 · other construction installation | 2022 | Active | SG3 |
| TAYLOR AND SHAW BESPOKE PROPERTIES LTD | 43290 · other construction installation | 2012 | Active - Proposal to Strike off | SG3 |
| BARNETT TECHNICAL SERVICES LTD | 43210 · electrical installation | 2017 | Active - Proposal to Strike off | SG3 |
Heat and planning around Knebworth
In Knebworth last summer (2026) there were ≈11 nights that stayed above 18 °C — 7 times the 1991–2020 average of 1.5 (ERA5 reanalysis, grid ≈30 km, lower than street temperatures in cities). The figure is the household-weighted mean of 1 postcode districts where these offices are registered.
10% of sampled postcodes in Knebworth sit in a conservation area (206 live postcodes across 1 districts).
In England an air-source heat pump on a house can be permitted development under Class G when the conditions hold, including the MCS 020a noise limit of 37.0 dB(A) (§3.2 Step 8).
Companies House snapshot 1 Sep 2026, retrieved 25 Sep 2026. The address shown is the registered office, not a verified operating base. This catalogue is a directory of incorporated businesses, not an exhaustive installer register. Hot nights: ERA5-ARCO, June–August, minimum at or above 18 °C, household-weighted across the districts where these offices are registered, retrieved 25 Sep 2026. Conservation-area share: sampled postcode points, snapshot 25 Sep 2026. Distances are an equirectangular approximation to 0.1 km.
Better than a town directory that only lists names: each plumbing company links to its Companies House record and the local hot-night count.