A boiler is a major purchase that affects your comfort and bills for the next 12–15 years. Here are the questions that actually matter.
1. What size boiler do I need?
Output (kW) should be sized to your home. An oversized boiler short-cycles and wastes gas. Always ask your installer to justify their recommended output.
2. What type of boiler is right for my home?
Combi, system, or heat-only? Each has different requirements and benefits. Read our comparison guide.
3. What warranty comes with this?
Manufacturer warranties range from 2 to 12 years. Always ask what's included and whether annual service is required to maintain it.
4. Is the installer professionally qualified?
Ask to see their engineer ID card. Non-registration is illegal.
5. What brand are you recommending and why?
A good installer explains their recommendation. If they only offer one brand, ask why.
6. What else is included — flue, filter, controls?
Make sure the quote includes a magnetic filter, inhibitor, and appropriate controls — not just the boiler.
7. Do I need a power flush?
If your system is old, a power flush may be required. Ask the engineer to inspect and advise honestly.
8. What are the payment options?
Most installers accept card or bank transfer, and some offer ways to spread the cost — ask upfront.
9. What Building Regulations certificates will I receive?
You should receive a safety certificate and Building Regulations compliance certificate.
10. What is your emergency cover?
Ask how quickly they can attend if something goes wrong post-installation.