How reliable are new boilers?

Condensing boilers cost a fair bit and aim to save energy, but no one knows how good they are
Saturday April 9, 2005
 

Householders will have to pay thousands of pounds to install condensing boilers under new government environmental regulations, but have almost no means to check their reliability before buying. An investigation in Jobs & Money last week revealed extensive concerns about the reliability of condensing boilers, which are designed to cut energy use by up to 40.
It prompted many readers to write in asking for a "best buy" list.

Alarmingly, no such data is available. Government departments and industry bod­ies willingly produce lists of the relative energy efficiency of the various models on the market, but were either unable or refused to supply data on their reliability.

Some of the manufacturers we contacted, such as Vaillant and Baxi / Potterton, said they would welcome any surveys on relative reliability, as these would help to dispel consumer fears about costs.

Unfortunately, the organisation which conducts the biggest and most authoritative consumer surveys, Which?, says testing of condensing boilers is a near-impossible task.

One reader, Jeff Bull of Epsom, Surrey, wrote last year to Which, asking it to test condensing boilers. But the organisation says it has not tested the machines, which are complex and may have problems which might not appear for several years.

The organisation employed by the government to carry out energy efficiency tests, the Building Research Establishment, said it was time for research into boiler reliability. Managing director David Strong said it would allow consumers to make a sensible choice.

British Gas is the only organisation to keep data on the reliability of condenser boilers. It recommends four makers following what it calls exhaustive research. It will allow customers to choose from German makers Vaillant and Worcester Bosch, and British firms Ideal and Baxi / Potterton.

A spokesman said a "data warehouse" measured the how many times different models broke down based on the 7m service calls the firm makes each year.

He said: "No one in Europe has more data on boiler reliability than British Gas and it's on this data that we select our products."

Jobs & Money asked if the company would publish the results of its mammoth survey. We were told it had never been publicised before and at the time of going to press refused to say whether it would release the information.

The spokesman maintained that all models supplied by the four manufacturers passed rigorous tests. He said: "It's also worth pointing out we maintain all of the boilers we sell as part of our 4m-portfolio of care customers. It is clear therefore that any additional costs would be borne by British Gas directly off our bottom line — why would we install boilers that we thought were unreliable and increase our call out frequency?"

Two-thirds of all households remain unaware of the new environmental regulations, according to Powergen. This level of ignorance is disturbing because households could be at risk of not being able to sell their home if they ignore the rules and buy a conventional boiler; from this week all central heating boiler installations fall under the control of building regulations and information will have to be provided in the new Home Sellers' Packs.

The sellers' packs, which are due to take effect in 2007, will give buyers a host of information about their new home, including an energy efficiency rating. It will be back-dated to April 2005, which means homeowners will have to produce a certificate to prove any boiler installed after April 1, 2005, is A or B rated and has been put in by a qualified Corgi installer.

Even before the packs come into play the purchaser's solicitor's search will flag up the missing documentation — which could delay the sale.

Under the new rules, all boilers installed in British homes must have an A or B efficiency rating, which effectively means a condensing boiler. But the efficiency ratings have been criticised by several boiler makers, including Baxi / Potterton. Models are rated for energy efficiency by a government quango called Sedbuk, but the rating bands are so wide all models are rated A or B, and most are in the A band.

A spokeswoman says: "This leaves little incentive for firms to improve their efficiency. If they are already A rated, that's as far as they need to go. Any further improvements are not reflected in the ratings."

According to government figures condensing boilers can save up to 37% on gas bills. That means, the government says, an average yearly saving of £160 for a family living in an average three- bed semi with an annual heating bill of £450. Ministers hope at least 1.1m will be sold before next April.

One energy supplier says: "This is the government's biggest move to reduce damage to the environment since the introduction of unleaded petrol in 1986.

Article source: Guardian Unlimited

 

Condensing boilers

Condensing potterton boilers are not new, they have been around for many years and users report very significant reductions in fuel costs. This is possible, because the condensing type of worcester bosch boiler has a much more effective 'heat exchanger' allowing more heat to be removed from the flue products.

One of the most significant effects of this is the 'pluming', sometimes mistaken for 'steam' coming out of the flue terminal. This effect is brought about by water droplets held in suspension in the flue products and although non-hazardous, it may be a nuisance if seen constantly passing across windows. This pluming will be evident for most of the time the condensing boiler is operating, so care is needed in positioning the terminal.

Although condensing boilers have a somewhat higher capital cost than non-condensing boilers, for larger dwellings (with three or more bedrooms) they usually prove to be cost effective within several years.

Typically, a condensing potterton gas boiler might have a seasonal efficiency of around 88% compared to non-condensing boiler of about 75%, and an older type boiler at between 55% -60%.

Condensing worcester boilers are as easy to install as any non-condensing boiler, but can only be fitted to 'fully pumped' systems. During it's operation, condensate forms and, although no more acidic than rain fall, a permanent pipe must be run to a drain.

Condensing boilers are available as a wall mounted or floor standing version.

Combination Boilers (Potterton combi boiler)

Most wet central heating systems use a boiler to heat a copper cylinder in the airing cupboard to provide stored domestic hot water. A combination boiler (usually referred to as a 'combi' ) provides a means of generating instant hot water for the taps from within the unit and combines this with central heating.

By using a 'combi' neither a hot water cylinder, nor it's feed tank, are required. Consequently, hot water running costs will be reduced very slightly since there are no standing losses from the cylinder or combination boiler pipework. Although a continuous flow of hot water is constantly available from a combination boiler, the flow rate is not likely to be as good as with a traditional storage cylinder, particularly in Winter.

In dwellings (often larger type) where a number of draw-off points (taps, showers etc) are likely to be used at the same time manufacturers advice should be sought as to the combi's suitability. Showers fitted to a combination boiler must be a 'mains pressure' type.

Because the combination potterton boiler is fed directly with mains cold water, it is vital to establish that the minimum water pressure, specified by the manufacturer, is available otherwise the hot water performance will suffer.

Combination boilers are by far the most popular worcester boiler type, accounting for over 50% of all new boiler sales within the UK.

A combi (instantaneous) boiler is the most widely used type of combination boiler and directly heats incoming mains cold water to supply hot water to taps, showers and other draw off points.

A combi (instantaneous condensing) combination boiler operates in principle as an 'instantaneous' type but at somewhat higher efficiencies

Radiators (central heating radiators, radiator covers, towel radiators, designer radiators)

Radiator 'heat emitters' can come in all shapes, sizes and forms. The most common central heating radiator is the steel panel type radiator and they are available in a very wide range of sizes and styles intended to match as closely as possible individual room needs.

Aluminium radiators are becoming increasingly popular, whilst the use of cast iron radiators is also on the increase where the intention is to blend with existing traditional decoration. Towel radiators are most often used in bathrooms and WC's where the towel radiator can be used to store towels as well as heat  the room as a bathroom radiator. Designer radiators are more money but designer radiators can make a design statement and be a feature in a room. You may decide to cover up a radiator with a radiator cover, this may be because the radiator is old or unsightly. Radiator covers come in many designs to suit your room decor and most radiator covers are made from mdf. Some radiator covers can be painted in your own colour scheme.

Radiators need to be matched to the room size and also how the room will be used to ensure the correct temperature can be maintained. How the house is insulated, including double glazing, can alter how efficient the radiators are at warming a house.

Worcester Bosch boilers Potterton Boilers Central heating boilers and radiators