Porthmadog: plumbing, heating and air-conditioning companies
Porthmadog has 6 plumbing, heating and air-conditioning companies (SIC 43220) and 9 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 LL49, summer 2026 had ≈2 nights above 18 °C there (12 times the 1991–2020 average of 0.2).
SIC 43220
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CARWYN AP PLYMIO A GWRESOGI CYF, incorporated 2025, status Active.
Plumbing, heating and air-conditioning companies
| Company | Incorporated | Status | District |
|---|---|---|---|
| CARWYN AP PLYMIO A GWRESOGI CYF | 2025 | Active | LL49 |
| DB & E WILLIAMS LIMITED | 2015 | Active | LL49 |
| ELIS LLYWELYN WILLIAMS CYF | 2022 | Active | LL49 |
| R HUMPHREYS & SONS LTD | 2008 | Active | LL49 |
| R J JONES PLUMBING & HEATING LTD | 2021 | Active | LL49 |
| MEDDYG CARE (FACILITIES MANAGEMENT) LTD | 2022 | Active | LL49 |
Electrical and other installation companies
| Company | SIC | Incorporated | Status | District |
|---|---|---|---|---|
| A. J BROWN ELECTRICAL CONTRACTING LTD | 43210 · electrical installation | 2013 | Active | LL49 |
| B & S SITING LIMITED | 43290 · other construction installation | 2012 | Active | LL49 |
| D.THOMAS ELECTRICAL CYF | 43210 · electrical installation | 2026 | Active | LL49 |
| E H A'I FAB YNNI ADNEWYDDADOL & TRYDANOL CYF | 43210 · electrical installation | 2024 | Active | LL49 |
| GARETH GRIFFITHS (TRYDANWR) CYF | 43210 · electrical installation | 2003 | Active | LL49 |
| NORTH WEST WALES ELECTRICAL LTD | 43210 · electrical installation | 2022 | Active | LL49 |
| O R ELECTRICAL LIMITED | 43210 · electrical installation | 2017 | Active | LL49 |
| TONY ROWLANDS ELECTRICAL LTD | 43210 · electrical installation | 2019 | Active | LL49 |
| CAMBRIAN ELECTRICAL (GWYNEDD) LTD | 43210 · electrical installation | 2019 | Active | LL49 |
Heat and planning around Porthmadog
In Porthmadog last summer (2026) there were ≈2 nights that stayed above 18 °C — 12 times the 1991–2020 average of 0.2 (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.
24% of sampled postcodes in Porthmadog sit in a conservation area (194 live postcodes across 1 districts).
In Wales 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.