Boiler Replacement

Boilers last 10-15 years

• Boilers usually only last for 10 to 15 years.

• Of course they can last a lot longer but they tend to become beyond economical repair, meaning the ongoing repair costs to keep your boiler running will quickly end up being more than the cost of replacing your boiler.



• So if your boiler is approaching the average age of it wearing out and needing replacing it might be more cost effective to replace than repair.

Regular breakdowns

• If you know your boiler repair man by name then your boiler is breaking down too much and it can become expensive very quickly.



• It will quickly reach a tipping point where it will make more sense to replace than repair; remember your boiler will need to be replaced at some point and that the replacement cost will be on top of all the repair costs, so deciding fairly early on to replace may be the most cost effective option.

Strange noises

• Banging, gurgling or whistling noises coming from your boiler is called kettling and is a sure sign there is something wrong with your boiler.



• There can be many causes for kettling such as limescale deposits, sediment or sludge buildup, leaks, and parts failing (e.g. the pump) but it’s generally a sure sign that you need a replacement boiler.

Strange smells

• If your boiler is giving off a strange eggy smell you need to act fast as it might be a gas leak from your boiler.

• Immediately turn off the boiler and gas supply, well ventilate the area by opening doors and windows, evacuate the premises and call a Gas Safe registered engineer quickly.



• The smell could be from a few causes but the dangerous one is a gas leak; natural gas is odorless so a scent called mercaptan (sulfurous odor) is added to help detect a leak.

Water leaks and drop in pressure

• Your boiler can leak water or drop water pressure for various reasons, many of which can point to boiler replacement being the most cost effective action.



• Parts can corrode over time leading to leaks and components can fail (such as pressure release valve, expansion vessel or auto-air vent) meaning the boiler can not function properly.

Poor heating performance

• Failing boilers can’t heat your home properly as they are not doing their job effectively.



• If your radiators are not heating up as they once did and your hot water supply is not reliable your boiler may be at the end of its useful life.

Yellow or orange flame

• A healthy boiler burns gas with a crisp blue flame, a yellow or orange flame can be a very serious and dangerous issue.

• If you notice one quickly shut down the boiler, get as much ventilation into the room as possible and call a Gas Safe registered engineer.



• If the flame is yellow or orange then the gas is not burning correctly which can lead to carbon monoxide production which can be fatal.

Hard to find replacement parts

• The older a boiler is then generally the harder it is to find replacement parts.



• So even if it can be repaired, as the part can’t easily be sourced, it might be much more convenient to replace the boiler rather than wait a long time with out heating or hot water for rare replacement parts.

Value or Premium brand

As the name suggests value boiler brands are cheaper than premium ones. But it's worth looking at bit deeper than headline price alone as more premium boilers tend to have higher grade components, better fuel efficiency and longer guarantees.

The premium boilers may well break down less, and if they do breakdown will tend to be covered by the longer guarantees. So a higher cost now could mean a lower overall cost, especially if the boiler breaksdown.

Which? Best Buy

Which? Gas Boiler Best Buys are run each September and are a useful independent guide on the boiler manufacturers with the best products.

Worcester Bosch have won this award an unprecidented 15 years in a row.

Reliability and reviews

Check out what other buys of the brand have to say about living with the boiler and how reliable it is.

A quick check before purchase can be very handy and save you time and money in the long run.

Guarantee length

The length of guarantees offered by boiler manufacturers differs wildly, typically ranging from 2 years up to 12 years.

The boiler brands offering long guarantees are usually more expensive, however you are paying for higher grade components that less likely to go wrong, so the extra investment upfront may be end up costing you less in repairs overall.

Energy Efficiency

The more energy efficient the boiler then the lower your gas bill will be as the boiler will need less gas to achieve the same heat.

So check out the ErP rating of the boiler manufacturer's models and choose the highest you can find.

Aftercare

Some boiler manufacturers have expert aftercare teams who will come out and sort any issue with you boiler whilst it is covered by the manufacturer guarantee.

National boiler replacement companies

British Gas are the best example of a national boiler installation company and are so called as they offer boiler replacements across the country.

• Typically have a well recognised and trusted name and a big fleet of boiler engineers.

• Tend to be more expensive than the other options due to the big overheads of running a big national business.

• Ususally have very good aftercare options to look after your new boiler through it's life.

Online only boiler replacement companies

Online boiler replacement companies have digitised the sales process and instead of sendign out an expensive sales person to you home to survey which type of boiler you need it is all done online.

• A few simple online questions and the survey is done.

• You choose your new boiler and pay online.

• Tend to be cheaper than national companies as they have smaller overheads and can pass the discount onto customers.

• The engineer comes on the agreed date to replace your boiler.

Local boiler replacement companies

Local boiler replacement companies are the most common. They generally just work around their local area.

• No salesmen, just the engineer who will come to your home and survey what type of boiler you need.

• Some offer boiler finance but generally it is just cash only.

• Also tend to be cheaper than National boiler companies due to much lower overheads.

Price is, of course, a very important factor to base your decision upon. But try to make sure the price comparison between boiler replacement companies is on a like for like basis. And if the other factors are not equal e.g. guarantee length, try to take a total value view rather than just headline price.

Some people know which boiler make they want and it's usually Worcester Bosch. Make sure the boiler company installs the brand you want and importantly that they are an accredited installer so your warranty is not impacted.

There are many ways to pay for a boiler but not all boiler companies will offer all routes. If you are looking for a particular pay monthy boiler finance offer like 0% interest free credit or no deposit then make sure your boiler company can help with this or choose one that can.

We've got all you need to know about boiler finance in our helpful guide.

If your boiler company repeatedly gives excellent service then they will normally have lots of good online reviews.

Do your research and check them out, ask family and friends for referrals of good boiler companies and use this as a filter to help shape your decision of which boielr company to use.

Long warranty and expert aftercare

Boilers can cost a lot of money. It's best to look around and make sure the warranty you get from your boiler company covers most of it's useful life (10 to 12 year warranties are fairly common).

And check that your boiler replacement company has a good record for aftercare; sometimes thinkgs do go wrong with boiler replacements and parts can fail but if your boiler company has a fantastic reputation for making things right you can have extra piece of mind.

Some boiler companies also offer boiler insurance or care plans which for a small monthly fee can give ultimate reassurance you are covered if something does go wrong.

Combi boiler swap: 4 - 6 hours

• Combi to combi and other same system type swaps can be done fairly quickly.



• It's not quite as simple as removing the old boiler and putting the new one back in the same place but it's not far off.

Changing boiler location: 1 additional day

• Moving the loaction of a boiler usually adds an additional day to the installation duration.



• The additional time (and expense) is due to running the required gas and water pipes to the new boiler location.

More complicated boiler jobs: 2 - 5+ days

• The more complex jobs take longer, as there is more to do.



• Changing system types, adding or removing water tanks, adding radiators or installing new central heating will dramatically increase the time it takes to replace the boiler.

1. Boiler replacement engineer arrives

Usually the new boiler will arrive with the engineer, or they will have arranged for it to be delivered to your home before they get there. They will utilise protective sheeting as required and generally prepare for the boiler replacement.

2. Old boiler removal

The engineer will turn off the electricity and gas supply to the boiler before draining all the water out of the system. Once done they will remove your old boiler and recycle it.

3. Clean the system

A chemical flush or a power flush is used to clean your central heating system to wash out any gunk that may impact the heat from your radiators or clog up your new boiler.

4. Necessary upgrades

The new flue and pipework runs will be fitted if needed. The new pipework may be required to meet regulatory standards or to best fit the new boiler.

5. Replacement boiler fitted

Your replacement boiler can then be installed into the correct location and fully plumbed in to be the gas and water pipes and connected to the mains electricity supply.

6. New accessories fitted

Now the replacement boiler is in situ it’s time to fit any accessories such as magnetic filters, condensate pumps or smart controls.

7. Commissioning the replacement boiler

The engineer will undertake checks to ensure your replacement boiler is safe and working in tip top fashion before handing it over to you and showing you how to control it.

8. Registration and warranty activation

Your engineer will then register the boiler with the Gas Safe Register and also activate your warranty with the boiler manufacturer.

Flue regulations

• Boiler flue regulations were last updated on 20th August 2024 with the aim of increasing safety regarding the proximity of a boiler flue and neighbouring properties, windows, doors and pavements.



• If the location of the old flue doesn’t meet the new criteria your engineer will have to make alterations.

Gas supply

• Gas pipes into modern boilers should be 22mm in diameter. Many legacy gas pipes are 15mm in diameter so will need to be upgraded to 22mm.

• A narrow gas pipe may restrict supply and lead to suboptimal performance from the replacement boiler.



• Your engineer will include a new gas run in your quote should you require it so it shouldn’t be a surprise cost.

Gunk and sludge

• Gunk and sludge build up over time in heating systems. It’s important to remove this when replacing your boiler and to protect it from getting into your new boiler.



• So your engineer will generally recommend and quote for a chemical flush or a power flush to clean the system and then install a magnetic filter to help keep it clean going forward.

Boilers and confined spaces

• Sometimes existing boilers are fitted in tight spaces such as airing cupboards or kitchen cupboards.

• Modern regulations require specified clearance gaps on all sides of the boiler and clear ventilation, otherwise they can not be fitted in the same location.



• Luckily many manufacturers produce a compact boiler with just this in mind.
  

Wiring regulations

• All wiring for boilers must adhere to the relevant electrical regulations such as BS 7671 (IET Wiring Regulations) and Part P of UK Building Regulations.



• Should the wiring for your old boiler not meet these standards then the wiring will need to be upgraded for your replacement boiler.

Water pressure

• Combi boilers have a minimum operating water pressure and they can not work properly below it, in fact most have a safety feature where they switch off should the water pressure drop below 0.5 bar.



• If there is not a sufficient flow rate a combi boiler will not be able to heat water in an efficient way. Your engineer will inspect your water pressure and be able to help advise if switching to a combi boiler is the right decision.
  

Power Showers and combi boilers

• Power showers don’t work with combi boilers.



• Combi boilers are pressurised systems fed by the mains water, whereas power showers use a gravity fed system and a pump to increase the water pressure and put simply they can’t work together.

Condensate drains

• All modern boilers are condensing boilers, which means they produce acidic waste water which needs to be disposed of safely to protect the boiler and also people.



• Older boilers don’t need a condensate drain so your engineer will factor in the addition of one into the quote for your boiler replacement.
  

Thermostats, controls and boiler plus

• Boiler plus regulations came into force on 6th April 2018 requiring all replacement boilers to have an ErP (energy-related products) efficiency of at least 92% and have time and temperature controls.

• In England and Wales Combi boilers must also have one additional energy efficiency measure such as flue gas heat recovery, weather compensation, load compensation or smart controls with automatic optimisation.



• In Scotland this policy is expanded to cover all gas boilers.