October 14, 2020

Which boiler would work best for my home?

Boilers explained - Combi Boiler

Always a common question whether it be from a client wanting to know about their heating system or someone looking to upgrade to a more efficient system.

A combination boiler produces all your hot water and heating demands for your property without the need of any other tanks in the airing cupboard or loft.

A combi boiler is usually fitted into flats and smaller properties generally with 1 bathroom/shower, this is because the boiler can only produce a certain amount of hot water per minute which is usually the amount required to run one decent shower at a time.

What are the advantages of a combi boiler?

  • Space saving
  • Never run out of hot water
  • Boiler guarantee from manufacture covers all internal components so no unexpected boiler repair bills ( typically 5 to 10 years depending on Manufacturer and model)
  • Combi Boilers can be fitted in kitchen cupboards, lofts, airing cupboards, garages etc
  • Only paying to heat the hot water you use

What are the dis-advantages of a combi boiler?

  • A combi is designed to run one outlet at a time so turning on another tap can affect the shower pressure and temperature
  • No back up of hot water if the boiler did breakdown
  • The combi requires certain water pressure and flow rates so if these are not achieved the combi will not work correctly

Boilers explained - Heat only /regular boiler/conventional boiler

A heat only boiler heats water in your system which is pumped to the radiators and separate hot water cylinder.

This type of boiler will usually consist of the following components

  • Hot water cylinder
  • Cold water storage tank in loft (large tank uslly 25 to 50 gallons)
  • A feed and expansion tank (smaller 3- 4 gallons typically)
  • A heating pump
  • 1 x 3 port valve or 2 x 2 port valve
  • Twin channel time clock and room thermostat

This type of boiler can be fitted into most properties, if you have low water pressure on the incoming water mains then this boiler is a good option for you. A heat only boiler can be as low at 12 kw and upwards of 30 kws covering most properties requirements.

These boilers can be fitted into lofts, kitchen cupboards, airing cupboards and garages etc.

The advantages of a heat only boiler is:

  • Can be fitted onto older systems provided they have been flushed through and chemically treated
  • The heat only boiler is usually tank fed so not pressurised which isn’t recommended to do to older systems and radiators as they could leak
  • Cheaper to replace like for like compared to other boiler changes
  • This type of system has a hot water cylinder and if the immersion has been fitted you will have back up hot water

Dis-advantages of heat only boilers:

  • The boiler guarantee only covers the boiler, the external components such as pumps and 3 port valves which are vital to the systems operation will are not covered
  • A lot of separate components to maintain ( hot water tanks, 2 x tanks in loft, pump, 3 port etc)
  • If these systems are not treated which inhibitors and piped up correctly they can produce quite a lot of air which isn’t good for the system which can cause corrosion within the system

Boilers explained – system boiler

A system boiler heats water in your system which is pumped to the radiators and separate hot water cylinder much the same as a regular boiler. However this boiler will have the pump and expansion vessel built into the boiler.

This type of boiler will usually consist of the following components

  • Hot water cylinder
  • Cold water storage tank in loft (large tank usually 25 to 50 gallons)
  • 1 x 3 port valve or 2 x 2 port valve
  • Twin channel time clock and room thermostat

This type of boiler can be fitted into most properties, if you have low water pressure on the incoming water mains then this boiler is a good option for you. A system boiler can be as low at 12 kw and upwards of 30 kws covering most properties requirements.

These boilers can be fitted into lofts, kitchen cupboards, airing cupboards and garages etc.

The advantages of a system boiler is:

  • Can be retro fitted onto an existing heating system
  • Can be connected to a vented or un-vented hot water cylinder
  • Less likely to have an airlock compared to heat only boiler
  • Pump and expansion vessel covered by boiler guarantee
  • This type of system has a hot water cylinder and if the immersion has been fitted you will have back up hot water

Dis-advantages of system boilers:

  • This system still has a few separate components to maintain ( hot water tanks, 1 x tanks in loft, pump, 3 port etc)
  • If connected onto an older heating system if there is a weak fitting or radiator joint then this could leak
  • Stored water means that if the programmer isn’t set up to meet your demands then you may run out of hot water

What type of boiler do you need?

This question is a answered by 2 questions, what type of property do you live in? & what is my hot water and heating demands?

A basic rule of thumb we always go by is

  • Flats and smaller houses with one bathroom = combi
  • Properties with more than one bathroom = heat only or system boiler

How can we can help?

Sometimes a client just wants to replace the boiler with a like for like swap, but the existing boiler may not be the right boiler for your property.

To determine this we would carry out a site survey where we would access the pros and cons and your usage to check what we specify will cover deliver.

At TheKentPlumber we also check the cold water mains pressure and flow rate if a combi or unvented stored water was required.