Welwyn: plumbing, heating and air-conditioning companies
Welwyn has 13 plumbing, heating and air-conditioning companies (SIC 43220) and 18 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 AL6, summer 2026 had ≈11 nights above 18 °C there (7 times the 1991–2020 average of 1.5).
SIC 43220
Open a company
AQUASPARK CONTRACTORS LIMITED, incorporated 2015, status Active.
Plumbing, heating and air-conditioning companies
| Company | Incorporated | Status | District |
|---|---|---|---|
| SPACE HEATING LIMITED | 2007 | Active | AL6 |
| SEHITI PLUMBING AND HEATING LTD | 2026 | Active | AL6 |
| C A WARNER LTD | 2015 | Active | AL6 |
| 360 HEATING LTD | 2014 | Active | AL6 |
| HERTFORDSHIRE PREMIER PLUMBING AND HEATING LTD | 2018 | Active | AL6 |
| DJ COX BUILDING SERVICES LTD | 2019 | Active | AL6 |
| TARGET DRAINAGE & PLUMBING LTD | 2022 | Active | AL6 |
| WARNER BROS PLUMBING AND HEATING LTD | 2015 | Active | AL6 |
| AQUASPARK CONTRACTORS LIMITED | 2015 | Active | AL6 |
| 360 MECHANICAL LTD | 2022 | Active | AL6 |
| OAKLANDS PLUMBING COMPANY LTD | 2026 | Active | AL6 |
| G & A PLUMBING AND HEATING ENGINEERS LIMITED | 2000 | Active | AL6 |
| R HOAD PLUMBING AND HEATING LTD | 2014 | Active - Proposal to Strike off | AL6 |
Electrical and other installation companies
| Company | SIC | Incorporated | Status | District |
|---|---|---|---|---|
| LUXE HOME DESIGNS & REFURBISHMENTS LTD | 43290 · other construction installation | 2023 | Active | AL6 |
| HERTS EV SPECIALISTS LTD | 43210 · electrical installation | 2020 | Active | AL6 |
| ACJ ELECTRICAL LTD | 43210 · electrical installation | 2016 | Active | AL6 |
| BECKS ELECTRICAL & BUILDING SERVICES LIMITED | 43210 · electrical installation | 2017 | Active | AL6 |
| MAEDEAN LTD | 43210 · electrical installation; 70229; 93130 | 2021 | Active | AL6 |
| GINN ELECTRICAL LTD | 43210 · electrical installation | 2018 | Active | AL6 |
| HUENIQUE LTD | 43210 · electrical installation | 2024 | Active | AL6 |
| SEALFIX CLADDING SYSTEMS LIMITED | 43290 · other construction installation | 2012 | Active | AL6 |
| OAKLANDS CONTRACTS LIMITED | 43210 · electrical installation; 41100 | 2017 | Active | AL6 |
| MNIC PROPERTIES LTD | 43290 · other construction installation | 2017 | Active | AL6 |
| CREST ELECTRICAL LTD | 43210 · electrical installation | 2022 | Active | AL6 |
| SHELF TALK LIMITED | 43210 · electrical installation; 31010 | 2026 | Active | AL6 |
| AUDIO VISUAL FACILITIES LIMITED | 43210 · electrical installation; 74909; 95210 | 2000 | Active | AL6 |
| EDEN MECHANICAL & ELECTRICAL LTD | 43210 · electrical installation | 2023 | Active | AL6 |
| ELITE KITCHEN DEVELOPMENTS LIMITED | 43290 · other construction installation | 2022 | Active | AL6 |
| G&G FENESTRATION LTD | 43290 · other construction installation; 43999 | 2021 | Active - Proposal to Strike off | AL6 |
| ADAE LTD | 43210 · electrical installation | 2021 | Active - Proposal to Strike off | AL6 |
| MARDLEY ELECTRICAL LIMITED | 43210 · electrical installation | 2019 | Active - Proposal to Strike off | AL6 |
Heat and planning around Welwyn
In Welwyn 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 Welwyn sit in a conservation area (506 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.