Replace boiler or not?

Sghughes42_2

I guess this is a cost over energy efficiency question...

I currently have a standard Baxi boiler with a hot water storage cylinder. I am out at work during the day and my partner only really stays over at weekends so hot water usage is fairly low.

I was wondering whether there are significant energy saving benefits to be had from changing to a combi boiler. I'm paying about £70 a month for gas at the moment but that is partly because they under-estimated my useage so are over-charging me to build up a credit balance for the winter - usage is probably more like £50 a month average.

The boiler I have is only about 7 or 8 years old - it has a minor problem in that it sometimes cuts out but that only lasts for 2 or 3 days when I change the settings - I think it may be the thermocouple.

Is it worth my getting a new boiler fitted or would I be better just getting this one fixed and sticking with it until it needs a major repair?

Any advice appreciated!

JonathanA

That sounds like a very high bill to me! We have a large semi house, a 25 year old boiler and my wife works from home, so energy consumption is higher than yours. we presently pay £30 per month for gas. Granted, we haven't lived here over a winter period (we moved in this March) and I do think it will be a cold house - old & lots of draughts, so our direct debit may be on the low side.

You need to decide whether you will live in the house long enough to get the payback from a new boiler. I would suspect that you would be better off having your boiler repaired and looking at other measures - better insulation, thermostatic valves etc rather than replacing the boiler.

I would suggest you get a quote for a) a new boiler and b) a repair to your existing one. If a new boiler is 10 - 15% more efficient that what you have now, it will take a long time to recoup the cost.

I'd also ask them to review your direct debit payment - after all, why should you build up a credit and let them have the money in their account!

mikeywills

A combination boiler can cost you anything from £500 through to a £1000 and beyond dependant on the size of your house.
I think your payments do sound a little high though, in my last house we had a combi for a three bedroom house of approx 100sqm, which used to cost us approx £100 a quarter. The advantage of combi's is they only deliver the hot water you require. The down side though is that if you have baths over showers they generally take a long time to fill anything from 10 to 20 minutes, as apposed to 3/5 minutes with a standard system. You have to base your choice on how long you intend living in the house and whether you believe it will be worth it. Bear in mind that combi's need more regular servicing than the standard baxi, (definately every 12 months) and in general are more expense to service. They also only have a life expectancy of about 10 years. To be more energy efficient look for a condensing bolier either as a direct replacement, or as a combination, as these take the efficiency of your boiler from about 80% to 95%, as they reuse the exhaust emissions a second time in order to benefit from the residual heat given off.
Good luck

Sghughes42_2

The house is fairly small - a 2 up, 2 down end terrace, but being 1860s construction has very limited insulation properties. I've tried putting extra insulation in the loft but I'm told we can't get cavity wall insulation as these houses don't have a cavity wall...

I rarely use the bath - generally shower only. Would this be a problem with a combi or can they cope OK with showers? (My SO wants me to add a pump to the shower as she feels the pressure is too low for her needs!)

My main concern is that I have to have the water heated up twice a day to be sure of having enough for when I need it, but a lot of the time that water goes unused.

As another option, is it feasible to get the tank stat connected in to the boiler control - i.e. to actually turn the boiler off when the water is hot enough? (It seems to just close the valve at the moment) Or is there a better way to do it - have the tank stat set very low but have the boiler on for longer so that when I actually draw water it heats up rather than heating at certain times?

kat21

yes, you would benefit from a change of boiler, all new boilers have to be a class A or classB efficient boiler (government reg) so, it would be a good investment. Choose a boiler that has plenty of spares available, we have worchester bosh, but I am sure there are plenty of popular boilers out there, that way parts are easily available should you need them.
kat21

melbury

When we had our boiler serviced recently we asked the guy about changing it for a combi one and asked if he thought it would save us money. He said the one we have got is fine (about 16 years old) and they don't make them like that any more - good solid cast (or something like that) He also reckons that combi boilers haven't been around long enough yet to prove all of the savings that are being claimed and therefore to just wait and see. Says that quite a few of his customers have experienced problems with them.

margaretclare

Hi S G Hughes

Your problem is similar to ours - see the Silver Savers board thread dealing with grants.

We live in a 1930s bungalow and like you, there are single-skin brick walls so no cavities for cavity-wall insulation. We have an Ideal Standard (similar to Baxi) type of back-boiler and small gas-fire (rarely used). I had this installed in 1992 because that seemed the best option at the time - arrived back from working in the Middle East in December to find the old boiler in the kitchen had died!

We're now thinking of having a condensing combi boiler in the loft space - there are huge lofts in these bungalows. We don't want the existing boiler ripped out though, just made inoperative, and the gas-fire left intact in case we want to use it (rarely).

Mainly though, we see no point in having a 40-gallon tank of hot water sitting in the loft having to be kept hot all the time. We're a pair of wrinklies who use the shower every morning, washing-machine twice or thrice a week at most, and apart from the usual washing-up and hand-washing, little use of hot water!

We've had very positive comments about combi boilers from the young couples around us who have them. Cost of our gas has risen from £28 a month at the start of this year to £58 a month now. So I'm not surprised a lot of people are seriously looking at this.

Margaret

mikeywills

Sghughes42 wrote:

The house is fairly small - a 2 up, 2 down end terrace, but being 1860s construction has very limited insulation properties. I've tried putting extra insulation in the loft but I'm told we can't get cavity wall insulation as these houses don't have a cavity wall... I should imagine that you have stone walls, if they are 400mm or over they will have the same heating properties as a cavity insulated wall anyway (see meers calculator guidelines

I rarely use the bath - generally shower only. Would this be a problem with a combi or can they cope OK with showers? (My SO wants me to add a pump to the shower as she feels the pressure is too low for her needs!)
What you should find is that the pressure of a good combi boiler is sufficient for a good shower, just make sure you have a thermostatic valve on your shower, if not the temperature will fluctuate if hot water is drawn off elsewhere in the house, (such as a washing machine, kitchen tap etc).Unfortunatley it is almost impossible to fit a power shower onto a combi boiler, as the number of litres per minute requested from the shower head exceeds that of all but the most expensive boilers. Pumps should really only be connected to a gravity system, (boiler, hot water cylinder and cold water tank.
My main concern is that I have to have the water heated up twice a day to be sure of having enough for when I need it, but a lot of the time that water goes unused.It is definately cheaper on a combi boiler, but calculate the costs over ten years to see if you are likely to make sufficient savings. If not just replace your existing boiler with a new condensing alternative. Worcester are one of the best and most reliable

As another option, is it feasible to get the tank stat connected in to the boiler control - i.e. to actually turn the boiler off when the water is hot enough? (It seems to just close the valve at the moment) Or is there a better way to do it - have the tank stat set very low but have the boiler on for longer so that when I actually draw water it heats up rather than heating at certain times?

You probably already have a thermostat on your cylinder, but if not put one on it. Good lagging should help retain heat during the day when you are not there.

justtoclarify_2

melbury wrote:

He also reckons that combi boilers haven't been around long enough yet to prove all of the savings that are being claimed and therefore to just wait and see. Says that quite a few of his customers have experienced problems with them.

Funny, I've been using combi boilers for about 22 years in the UK, conventional not condensing ones, with very few problems. Choose the right make, which is true of anything and you should have as good realiability as non-combi boilers. Combi boilers have been around longer in Europe. You just need to make sure you select one with hot water output rate appropriate to your needs. Some plumbers don't like combi boilers, don't know why, in small to medium size properties they work really well.

From next June (unless the Government changes its mind again) you will have to have an energy efficiency report to sell your house, changing the boiler now may be benificial now as well as at sale time. So improving your roof insulation at the same time would be worthwhile. If you have a lot of non double glazed glass, investing in some thermal lined floor to ceiling curtains can also help. This does assume your raditors are not placed under the windows.

All new boilers have to be condensing now whether they are traditional (boiler plus hot water tank vented or unvented), system or combination. The early condensing boilers ( circa 10 years ago) did have reliability issues with some makes, but the latest ones are much better. Some older boilers had an efficiency of less than 60%, to the OP if you can look up the make and model of your current boiler and find out its efficiency. Try http://www.sedbuk.com/ and run the numbers.

The other good thing about combi boiler is that you don't need a shower pump, I don't think building regs allow a pump with a combi. To make use of the mains water pressure hot water, you should change the shower cold water supply over to mains cold water. Otherwise the the water pressure between hot and cold will be unbalanced, this does not work well with a thermostatic or manual shower valve.

When I lived in a similar property a year ago (2 up 2 down, 1 bathroom) non-condensing combi-boiler albeit with double glazing I only used around £240 worth of gas annually. This was using the central heating for around 6 hours a day during the winter (late Nov - early Mar) and hardly at all during the rest of the year. Showers rather than baths. But could just be lucky.

amtrakuk

Well Im considering electric after BG has said my boiler is nearly BER at 7 years old. Drawing hot water is ok until you turn the tap off the the pilot light goes out and cant get it lit again.. The Bg engineer "fine tuned" the boiler (now giving crap performance). He says the heat exchanger is on its way out.

I got a few quotes and generally they ranged from £1800 to the unbelievable for replacing the boiler. I was told by a bloke a B&Q that yeah the 500-600 boilers are ok but will last you 3-4 years - cheap imports etc. The fitting, checking and corgi certification if I sourced my own would be between 300 and 400 so I looked at alternatives.

Electric, well its 99.8% efficient... I pay 16.559p/KWh with BG and then after 225 KW it goes down to 9.339p per KWh per quarter.

I went out and got a 1.2kw oil filled panel heater (£35.00). Came home and wacked it on full and after about 40 mins it warmed the room nicely. Listening for the thermostat click on and off i calculated a 9 mins heating and 12 mins off per heating cycle. Which based on 4 hours heating works out at about 34p per day to heat each room. I heat the front room, Kitchen hallway and bedroom, £1.40 for 4 hours per day heating or £45 a month.

Hot water. I just bought a 100 litre water heater off ebay for 250.00, the manufactures say it will heat hot water from 12 degrees to 70 degrees in 1.5 hours with a 3KW element with a 1KW loss over 24 hours if isolated. So I can have a shower once a day and have hot water left over for 74p a day or £24.00 a month.

Adding £24 for the hot water and £45 for the heating works out at £70 a month and thats based on 16p per unit of electric, not taking into account the cost per unit drops from 16.554p per KWh to 9.339p/KWh after 225 KW has been used per Quarter.

If I replaced my boiler with another gas combi... If i can get it replaced for 1200.00 and based on 10 year life the hidden costs come through. £40.00 per month for gas plus £20.00 maintenance plus depreciation of £15.00 a month comes to £75.00 a month to own and run my combi.

Terrylw1

Hi,

Over charging you to build up a credit balance due to an under charge? Whats the under charge based on, an actual reading off your meter? If not, they are simply raising your DD based on the fact it's a winter quarter and you would logically use more power than in the summer quarter.

They estimate based on the data they hold. If that data is all estimates which are wrong, they will always estimate your bill wrong.

Get customer readings to them when they issue your bill so you are more accurate. That will help address your DD.

Suppliers don't over charge to build up credit, they either raise it to cover an under payment (a debt built up) or they estimate what they think may cover a quarter based on season.