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New Boiler Considerations

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You’ve made the decision to replace your boiler.
The new gas boiler will heat your family and keep you warm.

The old boiler used to do this, so you are worried that you will have to cancel your cruise to cover the cost of a new boiler.


This is not true. Although a new boiler can be an unexpected expense, there are many options available to make your plans more flexible.
You should consider these things when purchasing a new boiler.

Can my boiler be installed safely and correctly?
If your boiler is not installed correctly, your warranty may be void.

Always consult a Gas Safe Registered Engineer.

Do your due diligence
It is worth looking into your new boiler as you would for your next big vacation.

Your boiler installer must be able to trust you and make you feel at ease. Each year, we visit a few customers in the Bromley area who have had their boiler installed incorrectly. This can cause safety issues or worse.

You can find reviews online on platforms such as Which? You can find reviews on platforms like Which, TrustedTrader or Checkatrade to verify the authenticity of the reviews. A quick Google search will often give you more information about the gas engineer or heating company you’re considering.

What kind of boiler do you need?

It is helpful to know what type of boiler you need. Is it a combi boiler or a regular heat boiler? What is the minimum power your boiler needs to heat your home, and provide hot water for your family? What warranty does your boiler manufacturer need?


Boilers can almost be found anywhere provided they have the clearances to allow for removal of the case for servicing or repairs.

Manufacturers can refuse to repair an item if clearances are not met.

Keep in mind, however, that 5 copper pipes and 1 plastic pipe are required to be inserted into the boiler’s bottom if it is a combi boiler. For a regular boiler, you’ll only need 3 copper pipes and 1 plastic pipe.

Consider the noise. While most people are quite quiet these days, it is still important to consider that we get called out often to move boilers from bedrooms into kitchens, garages, and lofts.

Your boilers flue

Your boiler flue is the last thing you should consider. The flue leaves the boiler’s top and travels outside in one of two ways: vertically through a hole in a wall (a vertical flue) or horizontally up and over your roof (a horizontal flue).

You will need to do some additional work, such as ladders. Also, depending on the height of the building (i.e. A townhouse may require scaffolding.

The flue terminal emits a plume, which is a light smoke-like cloud. It must be at least 30cm from any window, door, or airbrick. A plume kit can be used by a heating engineer to divert the fumes away safely if this is not possible.

Gas pipe

Your boiler may not function properly if your gas pipe is too small. You shouldn’t have any 15mm pipes running from your gasmeter to your boiler. It should be at least 22mm.

A 28mm gas pipe may be required for boilers above 36kw. Or at the very least, some pipe upgrades. It is not uncommon to need to upgrade gas pipes. Ask your installer if this is necessary as new installations often use old 15mm gas pipes.

Pipe clips

As a guideline, make sure you trim your gas pipes every 1 meter. Otherwise they could become noisy and loose.

Condensate and drainage pipe
This is the pipe that connects to a drain, either internally or externally.

It should be located after all waste traps. It is usually tapped in to an existing waste line. It should be at least 32mm in diameter to prevent freezing, and it should terminate below drain grills.

You can also use a soakaway or pump. If you are using a pump, the pipe must slope away from the boiler. Otherwise the condensate could back-up into the boiler and cause damage to your main heat. Externally, the slope reduces the risk of freezing.

If you are replacing the boiler and not having your system flushed, it is fitting a new boiler onto an older central heating system. This could be because the system has likely accumulated dirt and debris over the years. All the sludge, corrosion and other debris that has built up over time will be carried straight through your boiler, clogging everything.

Manufacturers won’t replace parts that have been contaminated with sludge under warranty.

If you are looking for boiler coverage, your insurance company will not cover damage to central heating systems or any other faults.

Make sure you have a high-quality filter installed on the return pipe. The boiler filter collects the sludge and stops it from getting into your boiler.

After your boiler has been commissioned by your installer ensure that he/she immediately registers your warranty (they only have thirty days to do so).

The installer must register your boiler install Bromley with Gas Safe. They will also need to provide you with a Gas Safe certificate if you ever decide to sell your home.