We see the same queries pop up again and again, especially things like “Can I move my boiler to another room?”, “What size boiler do I need for my home?”, and the big one for homeowners and landlords alike: “How much does a replacement boiler cost in London?”

Let’s take a closer look at these common questions to help you understand your options, avoid unnecessary costs, and make confident decisions about your home’s heating. Whether you’re renovating, replacing an old boiler or just trying to get your boiler to work properly, these answers will give you a clearer picture.

Can I Move My Boiler to Another Room?

Yes — in most cases, you can move your boiler to another room, but it must be done safely and correctly by a Gas Safe engineer. Many homeowners choose to relocate their boiler to free up space, improve the layout of a kitchen or bathroom, or move it away from a bedroom where noise can be an issue.

Popular places to move a boiler include:

When moving a boiler, your engineer will check flue placement, pipework rerouting, ventilation, and access for future servicing. The main factors affecting cost include the distance moved, the type of boiler, and how much pipework needs to be re-run. In London properties, especially older terraces and converted flats, this can vary significantly.

If you want to move your boiler, it’s a good idea to do it when replacing your old system. At Portman, we can discuss replacing your boiler in Hampstead, St John’s Wood or Marylebone. We’ll go over relocating it and the costs involved before we start work so you know what to expect.

What Size Boiler Do I Need for My Home in Fulham?

Wherever you live in London, choosing the right boiler size (measured in kilowatts) is essential for performance and long-term running costs. It’s one of the most common queries asked by homeowners searching online. The answer depends on the size of the property, the number of bathrooms, and how many people live there. 

Here’s a useful general guide for modern combi boilers, which are popular in London homes:

Small flat or 1–2 bedroom property

Medium terraced or semi-detached home (3 bedrooms)

Larger Fulham homes with 2+ bathrooms

For households with higher hot water usage, a system boiler with a cylinder is often a better choice. System boilers deliver strong, consistent hot water to multiple bathrooms at the same time — ideal for larger or extended homes.

Because properties in London vary from small flats to large Victorian houses, the best way to get accurate sizing is to have one of our Gas Safe engineers assess your heating and hot water needs. We have years of industry experience, and can suggest the right size of boiler for home in Westminster and Kensington.

How Much Does a Replacement Boiler Cost in Westminster?

If you’re wondering about the cost of a replacement boiler, the truthful answer is that the price varies depending on the boiler type, size, brand and installation complexity. 

On average, here’s what you can expect:

Combi Boiler Replacement:

£2,200 – £3,200
This includes the boiler, labour, controls and standard installation.

System Boiler + Hot Water Cylinder:

£3,000 – £4,500
Ideal for larger homes with multiple bathrooms.

Regular / Conventional Boiler Swap:

£2,500 – £3,700
Often needed in older properties where traditional systems are still in place.

Extra factors that can affect price:

Because Westminster, Kensington and Hampstead have many period properties, upgrades such as improving ventilation, fitting a new flue, or adjusting the gas run can influence the final cost.

The best approach is to get a fixed quotation from a qualified engineer working for Portman. Our team understands both London regulations and the specific challenges of properties in our area.