The Complete Homeowner's
Guide to Boilers

1. Types of Boilers Explained

Choosing the right boiler type is the single most important decision for your home's heating. There are three main types of gas boiler installed in Hull and East Yorkshire homes today:

Combi Boilers (Combination)

Combi boilers are the most popular choice in the UK, accounting for over 70% of new installations. They provide both central heating and instant hot water from a single compact unit, without the need for a separate hot water cylinder or cold water tank. This makes them ideal for smaller Hull homes with one bathroom and limited space.

Pros: Compact, space-saving, instant hot water, no tanks needed, highly efficient.

Cons: Can only supply hot water to one outlet at a time, may struggle in homes with multiple bathrooms, flow rate depends on mains water pressure.

System Boilers

System boilers work with a hot water cylinder (usually an unvented cylinder) to store and deliver hot water. All major components are built into the boiler, making for a cleaner installation. They're ideal for larger Hull homes with multiple bathrooms and high hot water demand.

Pros: Delivers hot water to multiple outlets simultaneously, mains-pressure hot water, no cold water tank needed, compatible with solar thermal.

Cons: Requires space for a hot water cylinder, hot water isn't instant (depends on cylinder recovery time).

Heat-Only Boilers (Regular/Conventional)

Heat-only boilers work with both a hot water cylinder and a cold water feed tank in the loft. They're often the best option for homes with existing gravity-fed systems that want a straightforward replacement without major pipework changes.

Pros: Ideal for homes with older radiator systems, can supply multiple bathrooms, compatible with immersion heater backup.

Cons: Requires both a cylinder and a cold water tank, takes up loft space, lower water pressure than unvented systems.

→ Learn more about combi boilers
→ Learn more about system boilers

2. What Size Boiler Do I Need?

Boiler sizing (measured in kilowatts or kW) is critical. An oversized boiler wastes energy and short-cycles, while an undersized boiler won't heat your home adequately. The correct size depends on:

• Number of radiators: More radiators require a higher kW output for central heating.
• Number of bathrooms: For combi boilers, this determines the hot water flow rate needed.
• Property size and insulation: Larger, poorly insulated homes need more heating power.
• Mains water flow rate: For combi boilers, this limits how much hot water can be delivered.

We calculate the exact size during your free home survey, taking into account heat loss calculations and your specific hot water requirements.

3. Understanding Boiler Efficiency

All modern boilers installed in the UK must be A-rated, meaning they're at least 90% efficient. But what does this mean for you?

Efficiency measures how much of the gas your boiler burns is converted into usable heat. A 90% efficient boiler wastes only 10p of every £1 spent on gas. An older boiler at 65% efficiency wastes 35p of every £1.

Upgrading from a G-rated boiler (around 65% efficient) to a new A-rated boiler (90%+ efficient) can save a typical Hull household £200-£340 per year on energy bills, according to the Energy Saving Trust.

ATAG boilers are among the most efficient available, with some models achieving over 94% efficiency—meaning you're getting maximum heat for every pound spent on gas.

4. Boiler Warranties Explained

A boiler warranty (sometimes called a guarantee) covers the cost of parts and labour for repairs if your boiler develops a fault within the warranty period. Here's what you need to know:

5. How Much Does a New Boiler Cost?

At Kingston Gas Services, we don't believe in one-size-fits-all pricing. Every installation is individually quoted based on your property, heating system, and requirements. However, here's a general guide:

We provide free, no-obligation home surveys and bespoke quotes. The price we quote is the price you pay—no hidden extras or unexpected costs.

6. The Boiler Installation Process

1. 1
   Free Home Survey: We assess your property, heating requirements, and hot water demand to recommend the perfect boiler.
2. 2
   Bespoke Quote: You receive a fixed, no-obligation quote based on your specific requirements.
3. 3
   System Clean: We power flush or chemically clean your existing system to protect your new boiler and validate the warranty.
4. 4
   Installation: Your new boiler is fitted to manufacturer standards with neat, professional pipework.
5. 5
   Commissioning: We test, commission, and register your boiler with the manufacturer for warranty activation.

A like-for-like combi swap typically takes one day. System conversions or full installations may take 2-3 days. → See our boiler installation page

7. Boiler Maintenance & Servicing

Annual boiler servicing is essential for safety, efficiency, and warranty protection. During a service, we perform a full strip-down inspection, clean critical components, test safety devices, and perform a flue gas analysis to ensure your boiler is operating safely.

→ See our boiler servicing page for full details

8. Common Boiler Problems

9. When to Repair vs Replace

As a general rule, if your boiler is over 10-12 years old and the repair cost exceeds £300, replacement is usually more economical. A new A-rated boiler can save £200-£340 per year on energy bills, meaning it pays for itself over time.

However, we'll always give you honest advice. If your current boiler can be safely and economically repaired, we'll tell you that. We never recommend unnecessary replacements.

10. Boiler Brands We Recommend

11. Smart Heating Controls

Upgrading your heating controls can save up to 30% on your energy bills. We install Tado and Honeywell Home smart thermostats, allowing you to control your heating from your smartphone, set multi-zone temperatures, and use geolocation to automatically turn down the heating when you leave home.

→ See our smart thermostat page

12. Boiler Safety Advice