For any new boiler replacement, the first thing we need to determine is the incoming cold-water flow rate, this is where we start as it will determine the correct size boiler for the property.
Once this has been established then we can start looking at boiler sizes. In this blog we are going to look at the four big boiler brands that dominate the market in this country, Worcester Bosch, Vaillant, Ideal and Baxi.
So, as previously mentioned the first thing we need to determine is the flow rate on the cold water main. Below is a rough guide as to what boiler should be fitted to the cold-water flow rate.
9-11 lpm 24kw
12-14 lpm 30kw
14+ lpm 35kw+
Anything below 9 lpm then a combi boiler is not going to be suitable for the property. There are ways to increase the flow rate with the use of boost pumps, accumulators, break tanks or fitting a new main.
Boiler Model |
Worcester 30icombi | Vaillant eco TEC pro 28 | Ideal Logic+ 30 | Baxi 630 |
Dimensions mm (HxWxD) | 710x400x330 | 720x440x338 | 700x395x278 | 700x390x285 |
Efficiency Rating | 94% | 89.3% | 89% | 89% |
Standard Warranty | 5 Years | 2 Years | 7 years | 7 Years |
CH Output (max) | 24kw | 19kw | 24kw | 30kw |
HW Flow Rate | 12.3 lpm | 11.1 lpm | 12.4 lpm | 12.2 lpm |
Mounting | Wall Mounted | Wall Mounted | Wall Mounted | Wall Mounted |
ErP Rating | A CH, A HW | A CH, A HW | A CH, A HW | A CH, A HW |
Average Price (inc VAT) | £1000-£1100 | £1000-£1100 | £850-£950 | £800-£900 |
Weight | 31.7kg | 37kg | 36.6kg | 29.5kg |
Pipes Run Behind Boiler | Yes | No | No | Yes |
Price is always one of the most determining factors when purchasing anything in life, let alone a new boiler. As you may expect the two biggest boiler brands are the most expensive to purchase. This is why it is important to research each boiler manufacturer to determine which has the best reliability and service.
On top of the price of the actual boiler itself you need to allow for the flue, filter, controls, flushing and the installation cost. Always make sure you get your 3 quotes before purchasing your new boiler.
Worcester Bosch do come out on top with the efficiency of the boiler at 94% while the others are 89%. To put this into financial terms for you, for every £1 you spend heating your home only 6p is wasted with the Worcester Bosch, as oppose to 11p with all the other boilers. Over the average life span of the boiler (10-15 years) that is going to make a difference of around £500-£600 on your energy bills.
Both Baxi and Ideal lead the way on standard warranty for the boilers. The best tip is to go on to each boiler manufacturers website and check for their accredited installers local to you. They may be able to offer you extended warranty on the boiler, just remember if you don’t ask you don’t get!!!!
Does size matter?? Well, yes it does, particularly if it is going inside a kitchen cupboard or being installed in a tight airing cupboard. One thing you need to bear in mind is if the pipe work can be run behind the boiler as standard. This save a lot of space in a kitchen area as you will not have to bring the pipes down adjacent to the boiler.
Both Worcester Bosch and Baxi allow this as standard, and while Vaillant and Ideal do stand-off kits to allow for rear pipe work it will affect the depth of the boiler.
To stay completely impartial, I would recommend all the boilers above as I regularly work on and fit these boilers so I know they will do the job they were designed to do.
If you have more than one bathroom in your property and regularly use more than one tap at a time, then you may need to consider some stored hot water to enable you to run multiple outlets at once. This should always be discussed with your boiler installation company on a survey.
If you would like any more information on which is the best boiler for your house, or would like information on a new boiler replacement then get in touch today
Matt Hughes is the Managing Director of Platinum Boiler Installations and his mission is to make boiler installations as simple and hassle-free for customers as possible. What Matt doesn't know about boilers simply isn't worth knowing! Connect with Matt Hughes on LinkedIn >>