welcome to cosywarm

The expression “no job too big or small” is often used but sometimes some jobs, it would seem, are just too small for some companies. This is not the case at COSYWARM as we started out back in 1976 doing the smallest heating and plumbing jobs around the Cardiff area and, over thirty years later, we haven’t forgotten our roots or our customers.

We are a small family-run business that succeeds only because of the reliable and efficient service we provide. Our engineers are vetted and skilled professionals and all are MCS, CORGI and Gas Safe registered. They are also fully covered by public liability insurance for further peace of mind.

Professional and Efficient

The best advertisement for any business is the recommendation of customers and we have received countless positive testimonials from satisfied clients in the greater Cardiff area over our many years in business for providing:

  • Top quality workmanship
  • Fast and efficient service
  • Excellent customer support
Boilers, Heating, Plumbing & Bathrooms
Boilers, Heating, Plumbing & Bathrooms
Boilers, Heating, Plumbing & Bathrooms
Boiler Servicing & Repairs
Boilers, Heating, Plumbing & Bathrooms
Central Heating
Bathroom Design

Our Price Promise

Not only do our heating and plumbing installations come with a Seven Year Guarantee but we are so confident of our ability and reasonable prices that we also guarantee to not just match but beat any quote from British Gas or Swalec for a like for like boiler installation.

Multiple Services

Installing heating and plumbing systems are our speciality but there are also other services that we provide which include:

Boiler Installation

As an Official Worcester-Bosch Approved Installer, we are qualified experts in the installation of their CDI range of boilers and all newly-installed boilers come with a Seven Year Guarantee for parts and labour.

Repairs and Upgrades

We can repair damaged or broken heating installations or upgrade the system entirely by adding or removing radiators or thermostatic valves to maximise efficiency.

Bathroom Design

Our team of experts can assist you in designing your ideal bathroom and then install it in double-quick time.


A low cost annual maintenance contract with COSYWARM will detect problems early and ensure your heating system runs smoothly.

Free Quotation

Why not call us at 02920 615111 to discuss your requirements and see how we can help you. We are available seven days a week and will be happy to give you a No-Obligation and Free Quotation on your project. Alternatively, you can contact us using the enquiry form on our “Contact Us” page.

Send Us Your Enquiry

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our accreditations


  • Mr & Mrs Chand of Treforest We are very impressed with our new Vaillant 937 boiler, which was installed, by Dave and Colin. From the first visit (by Alex ‘the boss’), CosyWarm carried out the job promptly and professionally. We were particularly impressed with Dave who was willing to listen to us (‘the customer’ as he puts it) and ensure that all our requests are discussed and fulfilled. Dave is an asset to CosyWarm and his exceptional work ethics is highly commendable. We, without any reservation, will recommend CosyWarm to all our friends and family as their professionalism and customer driven commitment is miles ahead of others competitors who have consistently let us down. Thank you very much to Alex, Dave, Kevin and Collin. Submitted By: Chandran

    Mr & Mrs Chand

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