Boiler Installation

Boiler Installation

So it’s time to replace your boiler, this is a big deal, ordinarily a sizable investment, so it’s crucial to make the correct choice from the off. We’ve decided to add this information to help guide you through the process and provide you with an insight into exactly what you need to know. 1 –

tradesman quote

1 – Quotes – identify at least 2 heating companies ideally 3 to provide you with quotes – make sure you confirm the potential engineers gas safe registration here -> click to confirm


2 – Type of boiler – know the type of boiler you want/ need 3 main types (domestic)

  • Heat only boiler -This model is straightforward, it’s a boiler in its most basic design and probably the most common boiler used in the UK. It just contains everything required to heat water which will travel around the cylinder and radiators. It requires an external pump to work. Heat only boilers are the only kind that can work on an open vented system, what I mean by that – it can be fed via the small ‘feed and expansion tank’ in the loft space.

heat only boiler Wellingborough

  • System boiler – This type is very similar to the heat only version, the main difference is, these are designed to be fitted on a pressurised ‘sealed system’ and they are equipt for that purpose. Inside it has an expansion vessel (I won’t go into detail about that now) additional safety devices plus it also contains its own circulation pump. These kind of boilers are perfect when it comes to a like-for-like system boiler replacement or if you’re replacing a heat only boiler and would like to remove the small feed and expansion tank in the loft.
  • Combination boiler – Combi’s are becoming increasingly popular, they have a few benefits that can’t be overlooked. A combi boiler essentially replaces everything on a standard heating system – they are fully pressurised, so there is no need for any tanks in the loft, a totally dry loft can be quite reassuring for some people. Your hot water becomes main pressure – a massive plus,  a lot of people in the UK have issues with upstairs tap/ showers not providing enough pressure as they’re tank fed, installing a combi would resolve this issue. Another big positive with a combi boiler is that your airing cupboard is totally stripped away – the hot water cylinder is removed as it is no longer required, freeing up some valuable cupboard space.

Ideal logic plus combi wellingborough

Hopefully, you found this breakdown useful, by now you should have a rough idea which system you may want to go for, the gas companies that provide you with a quote may advise a certain type that might be a better suit for your home. Treat this information as a guide and not as your decision maker.

3 – Choosing a boiler brand – This is important and equally a difficult decision. If you get a good vibe from your potential boiler installation company, you could simply ask them to recommend a boiler for you, or you could scour the internet for unbiased reviews. Personally, we find a manufacturer and stick with them, we have fitted pretty much all brands across the years including straight off the shelf B&Q (we absolutely don’t recommend those) – We now stick with Ideal and Worcester, two of the big guns in the industry. We stick to these for one reason – they seem to be more reliable for our customers (our opinion), we only want to return to our customers to service their boilers once we have fitted it for them, we never want to return to fix them if it can be helped, we choose reliability over everything. One crucial thing that we encourage you to insist on is a long warranty, a minimum of 5 years ideally. Some boiler brands have up to a 10-year warranty which in our opinion shows a manufacturers confidence in their kit plus, also – it’s a fact, a boiler manufacturer can repair a boiler easier and more efficiently than a regular maintenance engineer.

4 – Boiler sizing – This isn’t a point you really need to be worrying over, in most cases, it’ll be a like for like when it comes to the boiler size (kilowatt rating). If your existing boiler is an 18kw boiler normally the replacement would be an 18kw boiler, the only time this will be different is when you are converting to a combi boiler ( it will need to be bigger) or if you have plans to extend the system, add more rads etc… your boiler engineer should deal with this for you. A quick word of advice from us – when a combi is being fitted, radiators don’t really play a factor when it comes to boiler sizing, it’s more about the sanitary usage – the amount of hot water being used. If the home contains a bath only, we would consider a 24kw combi, however, if the home has a shower which comes off of the boiler we’d be looking to fit a 28-30kw boiler to ensure it is going to be man enough for the task and can cope with the demand. Your engineer will be able to advise you on this.

5 – Other points of value

  • Powerflush – When your boiler is replaced and installed on existing pipework, which is most of the time, the system should be power-flushed. It makes total sense, if you are to make this big investment the last thing you Wellingborough powerflushwant is dirty thick black sludge running through it and ruining your new boiler before its time. The latest boilers have numerous extra parts which can be affected by sludge. Combi boilers can fail within a year if the system isn’t correctly flushed throughout, there are many finely tuned passages and thin plates the water have to pass through to work, it will not take long for blockages.
  • System protectionMagnaclean filter – We fit these on all of our installations, without fail. It’s simply a magnetic filter which protects your system from sludge debris, it’s installed on a certain part of the system pipework to ensure all system water passes through it collecting sludge (steel deposits) as its flows. Normally cleaned once a year, this is a great way to protect your boiler. Scale filter – A scale filter helps combat scale build up in your boiler, another absolute must for anyone thinking of getting a combi. The introductions of new water to the plate heat exchanger every single day is going to inevitably lead to scale buildup. These particular filters are installed on the boilers incoming cold feed, most filters have a  lifespan of 5 years, some are longer, check the filters literature. Scale filters are only required in hard water areas.
  • Thermostatic radiator valves (Trv’s) – Thermostatic radiator valves have been around for a while now, you may already have them. They are useful but they can also be a pain in the arse.  Trv’s are designed give you more control of the heating temperature throughout the house, allowing you to turn a radiator off altogether if you want, plus they make your system more efficient improving your carbon footprint etc… but after speaking with some of our customers, we’d say there is about a 50/50 split so they are definitely love/ hate. The main gripe people had with them is – ‘radiators not getting as hot as they used too’ & “we have issues with the pins in the valves sticking” -Overall we do think Trv’s are a good thing – we just don’t push them on to our customers.
  • Gas pipework size We’re only going to touch on this subject as it’s getting more technical than we intended to go. This is a really big issue that we are seeing more and more of lately, in most cases it will be acceptable for a boiler that is being replaced for a similar boiler (kilowatt rating) to be fitted onto the same gas pipework. On the flip side, it’s almost never acceptable to use the same gas pipework to fit a larger boiler an example of this would be, ripping out a 15kw heat only boiler and replacing it with a 30kw combi boiler. The existing gas pipe has been sized to meet the demand of the old boiler – if the size has been increased, then so should the gas pipework. We are just putting this out there because we are seeing it a lot, you have to put faith in your selected engineer when it comes to this particular science.
  • Unvented hot water – Unvented cylinders are great, they are pressurised hot water cylinders that are directly fed from the cold mains. Normally fitted in homes with more than one bathroom, when combi boilers aren’t quite up to the task, it provides mains pressure hot water throughout the house. Similar to a combi boiler, only better. Perfect for bar mixer showers, essentially transforms them into a power shower. They don’t come cheap though, on average they price up at about £900 – £1000 but in our opinion, well worth it. Your installation engineer will size your cylinder to meet the demand in the home.


One final point, Once the boiler has been installed – you will need the engineer to register the new installation with ‘gas safe’, this is accordance with building regulations. You should receive a certificate from gas safe within Two weeks of the boiler being registered. Keep this safe, You will require this if you ever decide to move home, you will be required to show the building regulations certificate to prove that your gas appliance was installed by a competent person click here for more information.

If you have any question you would like to ask, please contact us via email at or call us on 07824429754.

This is just a helpful guide that will hopefully help a few people out, we find most of our customers are totally in the dark about almost all of these points, this is the reason we decided to type it out and provide guidance and assurance to all that are interested. Thank you for reading