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Greatplumbing Help Center

help centre


Hello and welcome to our customer support area!

This are is designed to help you with your frequently asked questions. We have created this section and divided it into the relevant areas listed below, so that we are able to resolve any issues you may have, as best as possible.

Take a look through the area to see if you can find the answer to your question and if you can’t find what you are looking for, feel free to contact our customer services centre on 07939939529.


Leading boiler manufacturers are:

Brand Name
This boiler make has a good and strong reputation with very few negative reviews. It heats water quietly and efficiently. Some negative reports say the controls can be rather confusing to use
These boilers are generally considered to be strong and efficient and are one of the market leaders. They are not the cheapest of boilers but are cost efficient and overall work out at very good value for money.
This is a good mid range boiler. They are generally pretty reliable and tend to cost less than some of the other brands like Worcester Bosch and Vaillant
With most of the Ideal boilers you will get a five years parts and labour guarantee. This is an overall sound boiler and also has optional easy to use wireless controls
These are reasonably priced and relatively reliable. They also have a high satisfaction score from their customers
A well known British boiler brand who have have won the Which magazine Best Buy award several times
This is a good budget boiler and is ideal for tenanted properties These boilers are not renowned for their reliability or long life span
These are middle of the road on cost but are generally good and reliable There are a few bad reviews about the customer service but nothing of great concern

In 2015, both Worcester Bosch and Baxi have updated their Greenstar and EcoBlue ranges, respectively. These new systems are designed to align with new efficiency standards set to affect all boilers from September 2015.



Review of boiler brands in 2017

An independent review survey completed by Which? of over 3000 consumers showed that Vaillant and Worcester Bosch are the most reliable boiler brands. Both scored an impressive 83% for overall customer satisfaction.

A low number of Worcester Bosch and Vaillant customers reported any problems with their boilers, just 32% and 29%, respectively, the lowest scores over the whole survey. Baxi also fared well, with their Duo-tec combi 28 HE model being named the best overall boiler of 2015.


Best for a 1 and 2 bedroom house

If you have a smaller 1-2 bedroom house, or flat, with only one bathroom then you will be best off with a small combi boiler. A small property will require a combi boiler of around 24-27kW. Here are our recommendations for the best small combi boilers in 2015;


Product name


Product number

Max. central heating output (kW)

Average price with installation*

EcoBlue+ 24
Ideal Boilers
Logic plus 24 HE
Worcester Bosch
Greenstar 24i Junior
ecoTEC Pro 28

Best for a 3 bedroom house

Average sized 3 bedroom houses, perhaps with one bathroom and an en suite, can benefit from a range of boilers. A more powerful combi boiler (28-34 kW) should suit your needs and is the easiest and least space demanding option. A new, energy efficient, conventional boiler (18-24kW), with a water tank, could also be an option. It is best to talk to a qualified installer to receive the best advice for your situation.

These are our recommendations of the best boilers for an average 3 bedroom house in 2015;


Product name


Product number

Max. central heating output (kW)

Average price with installation*

EcoTEC Plus 837
Worcester Bosch
Greenstar 34CDi
Solo 30 HE A
Worcester Bosch
Greenstar FS 30CDi

Best for a 4 bedroom house

Large, four bedroom and above houses, will have higher heating and water demands and will therefore require a more powerful boiler. Typically experts do not recommend combi boilers for larger houses as they do not cope as well with multiple showers/appliances using hot water simultaneously. However, a powerful combi boiler of 30kW and above may be suitable if that is your preferred option.

Speak to an expert installer to find out what type of boiler would be best for your property. These are our recommendations for the best boilers for large, 4 bedroom houses in 2015;


Product name


Product number

Max. central heating output (kW)

Average price with installation*

Flexicom 35hx
EcoTEC Plus 438
Worcester Bosch
Greenstar 42CDi
EcoBlue Advance 40


*Installation based on South East England, with no additional radiators, fittings, thermostats or powerflushing existing radiators. Correct at time of publishing, to be used as a guideline only.


Which type of boiler is best for me?

best boiler image

The type that will be best for you depends on the size of your home and your heating requirements.


There are 3 main types of boilers suitable for UK households:


Combination (combi) Boiler

A Combination boiler, also known as a ‘Combi’ boiler, is a very popular boiler selection for homes across the UK. One of the reasons for their popularity is that they can provide both hot water and central heating from the one appliance.

Unlike regular and system boilers, which require additional appliances such as hot water cylinders, water storage cisterns or expansion cisterns, a combi boiler removes the need for this as it heats your mains cold water supply on demand (i.e. from turning on a tap or shower etc) to give you a continuous supply of hot water.

This is an extremely efficient process as no energy is wasted in storing the water in a hot water storage tank.

A combi boiler therefore also takes up less space in the property once it is installed, which is perfect for a lot of UK homes where space is at a premium.

The image to the right hand side shows an example of a common combi boiler system set-up. Please be aware, combination boilers require a strong mains flow rate and this should be checked prior to installing one. Furthermore, a combination boiler may struggle to supply hot water to multiple outlets if they’re used at the same time, e.g. two showers, therefore, they may not be appropriate for properties with high hot water demand.


 Combi Boiler type


A combi boiler provides heating and hot water directly from the boiler. They are the most popular choicefor UK homes and are great for space saving.

Combi boilers are generally cheaper to have installed than other types of boilers as there is no tank and less pipe work involved.

If you are looking for a powerful shower then a combi boiler could well be the best option as the hot water is delivered through your taps or shower at mains pressure so there is no need for a pump.

+ Ideal for smaller homes or homes without much storage space

+ Cost and energy efficient

- Might not be suitable for homes with more than one bathroom


Regular Boiler (Conventional Boiler)


Conventional boilers, also known as regular boilers or open vent boilers, require a cold water storage tank in the loft along with a tank that maintains the central heating system’s water level.

They take up a fair amount of space, so your home or attic will need to be big enough.

+ Ideal for homes with more than 2 bathrooms

+ Best option for homes already with traditional heating and hot water system

- Require plenty of storage space

- Combi and system boilers more economical to run

A Regular boiler or a conventional boiler as some may know it are more commonly found in older properties. Regular and System boilers are an older design of boiler but still offer great functionality and control of your home’s central heating and hot water system. A regular boiler’s two main objectives are to provide central heating and hot water to your home. The way it heats your home is by directly heating the radiators throughout the property to your desired temperature.  The way it provides hot water is by heating a coil, which is fitted into your hot water cylinder in order to heat the stored water.  The hot water cylinder is fed from a cold water storage cistern (or the mains for an unvented cylinder) and a feed and expansion tank supplies the water for the heating system. 

Below you will find an example of a Regular boiler system set-up:


System Boiler

With a system boiler, the key heating and hot water components are built into the boiler. However it still needs a cylinder for storing hot water.

Unlike a conventional boiler, you don’t need a tank in your loft, but you don’t get hot water instantly and it can run out.

+ Ideal for homes with 2 bathrooms

+ No need for a water tank in the loft

+ Economical to run


A System boiler operates in a similar fashion to that of a regular boiler. Within its system it still operates using the principle of a stored hot water cylinder, but even though they have this same attribute a System and Regular boiler differ in some crucial aspects. A System boiler directly heats your homes central heating system and also produces hot water, which is stored in your hot water cylinder.  However, a system boiler has many of the major individual components of the heating and hot water system built in, which means that installation is quicker, neater, easier and more efficient.  A system boiler contains the central heating pump and an expansion vessel.  This removes the need for a separate feed and expansion tank and pump being fitted in to the central heating system.

Below you will find an example of a System boiler system set-up with an open-vented hot water cylinder:

Below you will find an example of a System boiler system set-up with a pressurised unvented hot water cylinder:


If you have any other questions or queries then feel free to give us a call and we will point you in the right direction.

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