Are Condensing Boilers more efficient in real life?

[D_Hailsham]

The big selling point of condensing boilers is that they are more efficient and will therefore save you money by reducing your gas consumption.

Has anyone, who has changed their boiler from non-condensing to condensing, done before and after comparisons of their gas consumption? If so what reduction in consumption did they achieve?

PS I have also posted this on another DIY site - there is no need to post two replies.

 

[bengasman]

Comparing gasbills before and after is not a very effective way of comparing the efficincy of the boiler; in most cases rads will be changed/added, trv's replacing wheelheads, and timers/roomstats will be changed.
Not to mention the fact that a lot of people will keep the heat on during the day as the habit of 1 hour in the morning and 3 at night is really a bit spartan.

It also depends on how you look at it; are you likely to earn back £2000 from the reduction of the gasbill? If you have a 6 bed detached and change from a backboiler, yes, and pretty quick at that.
A 1-bed flat changing an ideal mini to a steamer, and nothing else; that will take a while.
Is it worth the extra £300 quid that is effectively the difference between a properly installed condensing system vs non-condensing? Couple of years for most people to earn that the way the gasprice is going.

By the way, I would argue that improved efficiency is the selling point; in my view it is the fact that you can not legally install non-condensing in most cases that convinces people to install steamers.

 

[mattylad]

Not to mention the fact that a lot of people will keep the heat on during the day as the habit of 1 hour in the morning and 3 at night is really a bit spartan.

Could you please expand on this a bit BG to explain what your trying to get across

 

[bengasman]

Not to mention the fact that a lot of people will keep the heat on during the day as the habit of 1 hour in the morning and 3 at night is really a bit spartan.

Could you please expand on this a bit BG to explain what your trying to get across

This is the 21st century. In the 50s it was common practice to turn the heat on from, say 6 til 8 to get the chill out and warm the cylinder.
Then it would be off all day, sit in the cold, and on again from 5 til 8, and off to bed at 10.

With improved insulation, efficiency up from 50 to 90 percent, and higher demands for comfort, more and more people think it is perfectly normal to have the heating on for as long as you are home, and not in bed.

The latest version of roomstats don’t even have an off period anymore.

Times are achanging, 2 cars, 2 bathrooms, 2/3 toilets 5 phones, 4 tellies, 200 channels, holidays abroad in stead of blackpool, and a comfortable temperature all day. I call it: comfort/ quality of life.

 

[swbjackson]

I've had a couple of cases where big savings have been made but on both of them other things were altered.

I changed my fathers boiler from a BF to a condensing but at the same time upgraded to fully pumped and put a rapid recovery cylinder in. We saw a drop in gas consumption of about a third.

I changed my brother in laws boiler from a standard to a condensing and in doing so discovered that the old boiler had the flow and return incorrectly corrected. We also saw a drop in consumption by about a third.

I changed my boiler from a Worcester 350 combi to a Worcester 40Cdi condensing combi just over two years ago and haven't seen much drop in gas consumption but I already had TRvs throughout and an optimising programmable room stat.

If your existing boiler is in good condition and working well I can't see a huge benefit in changing it to a condensing boiler. You're better off upgrading the controls and improving insulation within the property as these will still be of benefit when the time comes that you need a new boiler.

Changing a boiler just to gain the energy saving of a condensing boiler is counter-productive as far as I am concerned. Leaving finance aside, if you look at the environmental benefits you need to take into consideration the total energy usage over the entire lifetime of the boiler. This has got to include the energy used in the production of the boiler. As a boiler gets older this gets to be a lesser proportion of the total energy usage. If a boiler is changed prematurely the average energy use per year will be considerably greater than if it was left to last it's normal lifespan.


Mike

 

[namsag]

One of the first thingsi tell customers is don`t believe the hype about cost savings its all worst case scenarios. And if that is there sole reason then don`t change boiler
Biggest saving people will see is changing from gravity hot water to proper fully pumped with cylinder stats and motorised valves. or betterstill combi
A lot of boilers fitted over the past 20 years where band d which was 78% efficent so the saving on condensing boilers at 86%/ 92% and this is not a constant with the effieceny droping down to low 80`s for a good while once they get up to temp the savings become hardly noticeable.
Proper cavity insulation draught proofing and loft insulation will save far more money and keep the house at a more even temp

 

[gas4you]

Of all the condensing boilers I have fitted, I have only had one customer who has said that the new HE boiler I had fitted has not given any saving in gas consumption over her previous boiler.

All the others without exception have told me they are saving between 20 and 45%/annum

 

[sooey]

All the others without exception have told me they are saving between 20 and 45%/annum

I've seen the size of you Dave, they're probably frightened to upset you.

 

[gas4you]

Not another one calling me a fat bast*rd at xmas

 

[sooey]

I would have said 'imposing' bast*rd, all the best mate.

 

[gas4you]

Happy New Year to you Ray

 

[Agile]

Virtually none of the customers I ever come across have the technical ability to correctly assess their consumption!

Most seem to think that the only indication of gas consumption is the monthly direct debit demanded by their supplier.

I once had powergen debit me £1000 per month on an empty property. It took a lot of arguing to get the overpaid £2235 refunded!

Tony

 

[gas4you]

Most of my customers have the ability to realise it is the increase in numbers on their gas meter that indicates their gas consumption, not what money is taken out of their bank account each month Tony

 

[Agile]

You are lucky because you are dealing with high class customers who want quality boilers installed in the houses they live in.

In London, many properties are rented out and the landlords having budget boilers fitted by very poor quality installers many of whom are not CORGI registered.

Tony

 

[jamesdean]

Has anyone, who has changed their boiler from non-condensing to condensing, done before and after comparisons of their gas consumption? If so what reduction in consumption did they achieve?

In Europe this has been going on for the last twenty years, but fortunately Britain is now slowly catching up and replacng combi`s with condensing boilers, with the promise that it will save you a fortune long term. It won`t and you have no choice. You want to heat your home ? you are gettin a **** combi.....simple as that...unless you fit underfloor heating of course...