- Abermaw Gas Heating
- 01341 280996 - Fronheulog Gellfechan Rd, Barmouth, Gwynedd, LL42 1DE
- A.J Pipeline Services
- 01248 724642 - Ty Newydd, Llangefni, Gwynedd, LL77 7YG
- Calor Gas (Calor Gas Direct)
- 0870 8147739 - 2d Glanydon Industrial Estate, Pwllheli, Gwynedd, LL53 5YT
- T.J Fixit
- 01286 676858 - Eisteddfa, North Road, Caernarfon, Gwynedd, LL55 1BE
- L Gardner
- 01248 853777 - 108 Lon Penmon, Benllech, Tyn-y-Gongl, Gwynedd, LL74 8RR
- Gas Care Central Heating
- 01248 372442 - Llandygai, Bangor, Gwynedd, LL57 4YH
- Brian Jones
- 0870 7574481 - Y Wenllys, Ffestiniog, Blaenau Ffestiniog, Gwynedd, LL41 4LH
- W.G Jones
- 01758 740457 - Bryn Goleu, Llanbedrog, Pwllheli, Gwynedd, LL53 7NU
- Morton Services
- 01758 612800 - 2d Glanydon Industrial Estate, Pwllheli, Gwynedd, LL53 5YT
- Oakmere Plumbing
- 01286 674610 - 9 St. Helens Road, Caernarfon, Gwynedd, LL55 2YD
- I Parry
- 01248 853742 - Gwel Y Don, Marianglas, Gwynedd, LL73 8PA
- Power Services, The
- 01286 676727 - Caegarw Llanberis Rd, Caernarfon, Gwynedd, LL55 2DF
- Profile Services
- 01248 670450 - Y Felinheli, Gwynedd, LL56 4JR
- A.G Twitchett
- 01286 881442 - 56 Bryn-Celyn Rd, Talysarn, Caernarfon, Gwynedd, LL54 6AB
- Cadnant Plumbing & Heating
- 01248 717169 - 9 Mill Lodge Estate, Llandegfan, Menai Bridge, Gwynedd, LL59 5YB
- Astbury Heating
- 01248 372400 - Penybont, Treborth, Gwynedd, LL57 2NX
- J & E Evans
- 01341 247617 - Doigau Gwynedd, Dyffryn Ardudwy, LL44 2RQ
- Dew Plumbing and Heating
- 07789 968427 - 17 Manod Road, Blaenau Ffestiniog, Gwynedd, LL41 4DE
- Llanfair Gas Services
- 0845 2634096 - Gwynllys Park Crescent, Llanfairechan, Gwynedd, LL33 0BA
- Gaslec Technical Services Limited
- 01341 247973 - Brif Heol, Dyffryn Ardudwy, Gwynedd, LL44 2DG
- Lawton Heating & Plumbing
- 01286 678861 - 10 Glanffynnon Rd, Cearnarfon, Gwynedd, LL55 4PS