10 Tips Before Fitting New Boilers

New Boilers

If your reading this your probably either in the process of getting a new boiler installed or you’re considering it,

either way, it’s a huge financial commitment,

so being well-educated on the matter is always a good idea,

on that note, I have compiled a checklist and you should,

outlining what you should know/consider before going through the mundane task of getting estimates.

What size boiler do you need?

• The average combination boiler comes in one of four sizes 24kw, 28-30kw, 30-37kw and 40kw, as a
• rule of thumb a 24 is ideal for most flats and any smallish 2-3 bed house with anything roughly up to 10 radiators,
• a 28-30 would be for a medium to large 3-4 bed house with up to 15 radiators, a 30-37 and a 40 km
• would be for a large house with anything up to 20 radiators. For hot water the
• higher demand (how much hot water you use) the higher kW (kilowatt) boiler required,
• however, no combination boiler will cope with 2 showers running at the same time,
• don’t take these figures as gospel they are just a guideline before getting your quotes in.
• The most a combination boiler can give on hot water is around 16 litres of water per minute

Location Of The Boiler

• The easiest and cheapest place for any boiler to be installed is in the same location as the old one,
• the reason for this is that the pipes are all in the vicinity,
• if your going from a combi to a combi then every pipe will be there,
• however, if you’re converting from a system boiler to a combi( a system with a hot water cylinder and header tank),
• there is a good chance that the cold and hot water pipes will have to be “run” to the new boiler.
• A boiler can basically be installed on any wall as long as it’s near an outside wall in
• order for the flue to exit and a drain (explained later), also needed are gas, flow and return(radiator pipes), hot and cold water pipes.

A pipe must leave the boiler and exit into a drain.

• All boilers by law must have a sedbuk efficiency rating of A or B, this means that they
• must be “condensing”, all condensing boiler’s produce condensation,
• this condensation leaves the boiler (in liquid form, Water) via a waste pipe, this waste pipe must exit into a drain, either an outside drain or it can “tap” into a
• sink/bath/washing machine waste inside the property, the pipe must have a downward slope of at least 5%.

What Brand and make of boiler to choose?

• I recommend 5 boilers to my customers, Vaillant Eco-Tec, Worcester junior, Baxi Duo-tec and platinum and the Ideal Logic+.
• I don’t think you will go far wrong with any of the boilers mentioned,
• the Vaillant and Worcester are the most
• expensive but only come with a 2-year warranty, ( Update See Below)the Ideal Logic is the cheapest of the 5 but comes with a 5-year warranty,
• I recommend getting some brochures (give me a call if you would like me to send you some) and really doing your research,
• but like I said any of the 5 I am happy to recommend.
• We now offer a 7 Year warranty on the 
• Vaillant Eco-Tec Plus and 5 Years on the Pro version.

What size is my gas pipe?

• If you’re a bit of a do it yourself with this sort of thing, or you have access to your old boilers installation
• instructions, then check the size of the gas pipe pip going into the boiler it should be 22mm thick if its 15mm
• thick it may need to be increased, make sure you ask the installer doing your quote to tell you the
• size, as your new boiler may not function properly if it’s too small.

What thermostat controls do I need?

• With any new central heating system, you must have a minimum of a room stat, the cheapest and best
• the option is a wireless room stat. contrary to popular belief there are no laws stating that you must have thermostat radiator 
• valves ( i have contacted gas safely and had this confirmed),
• what they say is that an installer should recommend them, to a
• customer and quote for them, but you don’t have to
• have them, but I do advise getting them installed in bedrooms at least.

Getting the system flushed.

• Your warranty will be void if your new boiler becomes damaged because of sludge from your system. To prevent this the system must be flushed, it’s also advisable to get a central heating filter installed which will help combat sludge build-up for as long as its installed. I recommend MagnaClean Professional they fit inline on the boiler return pipe.

Water pressure. Every combi boiler needs a minimum cold water flow rate requirement, it is vital that this is tested prior to the new boiler is installed

How long will it take? 

• An average combi to combi exchange will take 6-10 hours (normally done in one day) a conversion (system boiler to combi) would normally take 2-3 days, so be prepared for at least one night without hot water or heating if getting a conversion

How much will it cost? 

• The question everybody wants to know, as a rough guide a combi – combi exchange will cost between £1600 and £2600(inc vat) depending on size and type of boiler a conversion will be between £2200 and £3500(inc vat) this is a guide for London companies if you live in the north of the country then you can probably find it a little cheaper.