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ABOUT BOILERS, THE BASICS.............

Conventional versus combination boilers - the pros and cons:


A Conventional boiler is purely a heater - there will be an external hot water cylinder, control valves and radiators.

Why would you want one?

- More than one hot water outlet can be supplied simultaneously (dependant on a separate storage cylinder)

- You have a larger house and need a space heating output greater than 100,000BTu (30Kw)

- You desire a longer service life for a boiler than 10-12 years.

- You would prefer to have a stored hot/cold water supply in the house

- You may have recently invested in a new hot water cylinder/tanks

- You want an electrical immersion heater as hot water backup for boiler failure

- The water flow rate (sometimes erroneously described as pressure by plumbers) is too low for a combination boiler (but see low water mains pressure solutions as there are solutions available)

- Perceived reliability advantage.


A Combination boiler contains all the necessary controls and equipment to provide instantaneous hot water and also central heating - apart from radiators and pipe, everything else is in the boiler.  There are now over 7 million households in the UK equipped with Combination boilers.

Why would you want one?

- Convenience. Hot water is always available, 24 hours a day

- Economy. Only heat the hot water you use.

- Consecutive hot water demands can be made without running out

- You do not require to run two hot water taps simultaneously

- No water tanks in the roof or hot water cylinders are required.

- It's a one box compact solution, ideal for small properties

- It offers mains pressure showering without an electric pump (ideal for flats or loft conversions)

A note about reliability:

Combination boilers are considered by some to be less reliable than Conventional units.

It's important to remember that the combination boiler does the equivalent of a conventional system, but in one box.  It removes the need for external;

Central Heating Pump
Hot water Cylinder
Water tanks (both)
Motorised Valves
Hot water thermostat

All of which would otherwise be needed (and occasionally repaired) in a conventional system.

Providing a combination boiler is connected to a properly cleansed system that is dosed with corrosion inhibitor there should be no discernable difference in reliability.   Your decision should be made on the features and benefits. 

It is a general rule with boilers that you get what you pay for.  We only recommend products we have found to be reliable and which are well made.   

Condensing (High efficiency) - what you need to Know

Condensing High Efficiency Boilers - an explanation:

Older boilers emit flue cases which are very hot (in excess of 160 degrees). This is rather wasteful because most homeowners purchase a boiler to heat their house, rather than the surrounding countryside.

With older boilers between 20-35% of every £1.00 spent on gas goes out as heat into the garden.

For some years, high efficiency boilers have been available for industrial and large domestic systems, but their use has not been widely publicised. These units recirculate their hot exhaust gases until more useful heat has been extracted into the boiler, before expelling a much cooler exhaust. The cooler exhaust contains particles of water, (or condensate, as it is described in the trade) which create a visible 'steam like' plume.   The condensation deliberately encouraged within the boiler helps transfer more heat into the radiators.

Boilers which recycle most of the otherwise wasted flue heat are therefore called 'condensing'.  All boilers described in the UK as 'high efficiency' can be assumed to be condensing boilers. 

Condensing boilers are available for Gas, LPG and Oil fuels, and come in 'conventional' and 'combination' types.

Government Intervention:

The UK Government signed an international agreement (Kyoto Agreement) committing us all to reducing energy losses. As a result, from 2005, it became mandatory for UK homeowners to install high efficiency 'condensing boilers' when fitting a new gas unit.

Oil boilers became subject to this ruling later in 2007. See 'exceptions' below.

The Government class these units as having an efficiency of SEDBUK of grade 'A' or 'B', which is top marks in laymans terms (see www.SEDBUK.org for more information).    Similar markings are available for domestic appliances, light bulbs etc.

Condensing boiler reliability:

Unfortunately, over the last 9 years certain domestic boiler manufacturers may have exhibited undue haste in releasing their condensing boilers onto the market, before they had been fully tested. There have been some expensive failures, and it is regrettably not uncommon to have to scrap a condensing boiler but a few years old.

Whilst they are undoubtedly more complex, there is no reason why a quality condensing boiler should be any less reliable than a standard unit.

The key is to buy from a volume manufacturer with a large Research & Development budget and a good reliability track record; which brings us back to Vaillant , Worcester Bosch, Viessmann , Broag-Remeha, Grant.  For those of you lucky enough to own larger properties we suggest you may also wish to have a look at our Archie Kidd page.

Exceptions to the 'condensing only' Building Regulations:

Many of our European cousins have been successfully running condensing boilers for years. However, European installations tend to use 'vertical flues' where they protrude through the roof. The condense pluming is therefore far less visible and irritating than in the typical UK installations, which tend to use horizontal flues (ie: wall mounted).

It is recognised that there will be situations, particularly in high density housing, where the condense plume from a horizontal flue will be unacceptable to residents, or where the flues are shared within a central duct which may not be practically viable to alter.

Therefore, there are exceptions to the Government mandate, some non-condensing boilers will continue in production to cater for this market.  Over the past few years we have found very few homes that could be classed as exempt, although some high rise modern dwellings could qualify.

We can't see why anyone would want to use more fuel than necessary and achieve an exemption. 

However, those who don't want a condenser may be interested to know that a range cooker with an internal boiler is exempt.  Even if the boiler is totally separate from the cooker;  it just has to be within the same casing, such as our Heritage Cookers (see menu top of page).

Our advice:

If you want reliability, specify a good boiler, whatever your preferred choice of system, rather than a budget unit.

We only fit the former!

Condensing technology, more background:

The high efficiency boiler was introduced in the UK by Archie Kidd. Whilst today's media suggest the idea is the latest thing, you could have bought a condensing boiler from Mr Kidd in 1982, and chances are, you'd still be using it now.

Today's condensing boilers work on a similar principle of transferring as much heat from the fuel being burnt, to the water in your pipes. The last 10% of usable boiler efficiency requires the (gas or oil) fuel's internal water content to condense inside the boiler, against the water jacket. The 'latent heat of evaporation' gives away more energy when the water in the fuel is encouraged to turn from a gaseous to liquid form.

With all the extra efficiency, the flue gases emitted from the boiler to outside are of a much lower temperature; this way your boiler wastes less valuable fuel heating the garden. A disadvantage is your flue tends to look a bit like a steam train’s funnel in winter.

There’s been a lot of negative publicity in the press about condensing boilers. It’s true that a significant number of boilers from 2000 onwards – culprits being predominantly British and Italian manufacturers - have already been scrapped by their owners.

Some manufacturers fretted about being left behind, desperately rushed through models which had not been comprehensively tested or funded - these boilers are the ones you have read negative comments about.

The condense in a high efficiency boiler is designed to be safely led away to the drain. The trouble is, there is a weak mix of acid present in the water condense, which will rot copper, steel, iron and even some plastics with a vengeance. Consequently, modern condensing boilers tend to be made of expensive metals and alloys like stainless steel and aluminium, which can tolerate the harsh conditions better.

The good news is manufacturers are getting better at designing out the weaknesses. Some of the German manufacturers have been making condensing products for over 15 years.

If you really don’t want a condensing boiler, you could fit a range cooker with a boiler in it –they’re exempt from the regulations. See our Heritage Range page.

Solar:

Solar hot water heating:

We are solar heating installers...

We recommend the Worcester Bosch Greenskies system, and have attended the manufacturer training courses.

Typical Worcester solar system

Worcester Bosch are one of the most honest solar manufacturers in the UK. 

If you visit their web site you will not be given a dubious sales pitch but, in our view, the real pros and cons of solar. 

Nowadays there are all sorts of salesmen pushing solar, even double glazing companies are promoting it.

There is a case for solar thermal hot water if you care about the environment and want to minimise your impact on the use of fossil fuels.  But be careful to separate the hype from the fact, and make the decision for the right reasons.

A new development from Worcester is a controller which maximises the input of the solar panel to your hot water storage, and minimises the intervention of the boiler.  This is based on learning usage and sunlight routines for the household and combining this with calendar based statistical data on sunlight emissions during the year.

Called the FW100, this unit also runs the boiler in weather compensation mode, altering the circuit temperature of the radiator loop according to the external air temperature, to maximise the condensing routine in the boiler.

Worcester boiler and solar controller FW100


Worcester ISM1 solar optimiser

This new controls, launched in May 2009, come from the Bosch Junkers division in Germany, and are presently only compatible with the Worcester Bosch Greenstar 30CDi system boiler.

A few facts about SOLAR hot water - so you know what to expect;

Many householders in pre 2000 homes do not appreciate that hot water accounts for only a very small amount of their gas or oil bill.   Typically only 15-25%.

"Free Hot Water for Life" is a slogan often used by solar salespeople.
 
Adding solar panels will typically provide 50-70% of a household hot water requirement.  Therefore if your water heating bill accounts for 20%, and solar will address around 70% of that;  you stand to save around 11%-12% per year.  Doesn't sound so impressive now.  But the comment 'free hot water for life' is still valid though.......just another example of how the truth can be manipulated.

Most of your gas bill (80%) goes on space heating (eg: radiators), which cannot be economically addressed by UK solar systems.

It typically therefore takes at least 20 years to recoup it's investment – much longer than we statistically stay in one house.  Because the systems are only designed to last 20 years, and need regular maintenance (eg: anti freeze top ups) we calculate payback occurs somewhere between 30 and infinity years, assuming nothing goes wrong in the meantime.  

BBC's Watchdog have recently published an interesting feature on a solar sales pitch.

The truth is that solar panels are an altruistic way of reducing your energy consumption, and therefore your impact on the World.  They will probably not pay you back for their investment, but they will get within 50% of this.  Very few home improvements will make this impact, other than insulation.

If you have a swimming pool solar does start to make excellent financial sense though, because you are heating 20,000 gallons of water. 

We'd suggest you might like to look at Heat pumps, or our Hometronic radiator management system, before investing in domestic Solar hot water.  If you want a solar hot water system, we recommend and fit the Worcester Bosch equipment, which is made by Buderus in Germany.

What really amazes me is how many households have gone to the expense of solar panels, but still have a polluting, energy guzzling 60% efficient old boiler.  Or worse still, an AGA.  Don't get me started.

Powerflush:

We always Powerflush an existing radiator system before replacing the boiler. This ensures a long and reliable service life, and helps return the system to original condition.

We use the industry leading Norstrom Powerflush units, which are designed to have a high flow rate into the radiators.

Warm Air Central heating:

Warm Air Central Heating:

It's not widely appreciated, but Gas Warm Air Systems are amongst the most efficient forms of heating available.

Their heating output is nearly instantaneous, and there are none of the water leaks, sticking valves, sludge, pumps, etc. than can develop with ordinary systems. As a result Warm Air installations typically have a longer service life than water based systems. There are many householders who are committed advocates of this method of central heating across the UK.

The latest Warm Air boilers incorporate significant technical advances over their forebears. On current models, instead of the basic on/off nature of old Warm Air heating systems, there are electronically controlled fan speeds and temperature regulation, making the action of the boiler much more subtle. These improvements offer significant comfort and economic benefits to the homeowner when upgrading. 

In 2009 we stopped installing Johnson & Starley warm air equipment.



We now recommend and install Lennox condensing warm air units, which are significantly more efficient (up to 95%) than any other unit available in the UK.  And a lot more efficient than radiators.

Lennox are a US based manufacturer, where (unlike the UK) warm air is a massive market with the competing manufacturers still investing large sums of money in product development.  Some UK houses are still fitted with Lennox heaters from the 60s and 70s.  These have proved to be very well made and reliable - the good news is that Lennox are now importing into the UK and can be fitted by key installers.

In the USA air conditioning and warm air are often amalgamated, and we can offer this in the UK too, using a G61V and a Lennox air con unit, running through your existing ducts.

Lennox G61V range

Ask us for more details - Our 'installation blog' is currently being updated with some of our recent GV61 installations.

Radiators and Underfloor Heating:

Go to our Radiators and Underfloor heating page.