Opinions please-Should an old c/h system be replaced ?

[johnbrian.lacey]

The c/h boiler in our house is at least35 yrs old, the pipes and radiators must be a similar age. The boiler is serviced each year, it works fine. Basic , simple controls, just water temp and timer for ch and hw. I am a great believer in 'if it aint broke then don't fix it !' I know that it is not efficient but it keeps us warm and causes no problems. I asked the service engineer about replacing and he told me that a new boiler would have problens with the mucky water in our old but sound pipes and lots of double panel rads. Big water flow through lots of big pipes then going into a new boiler that would not like any contaminated water at all. New boiler I can cope with but not a complete c/h system in an old property that is our home ! His opinion of modern boilers was not high , he is ex British Gas. Poor quality metals used, regular parts failure after only 3/4 yrs etc.

Any opinions on this would be helpful.

Thanks

Brian

[Frank Erskine]

The question would seem to be "Why do you want to replace it?".

Thirty-five years ago boilers were built to last, whereas modern (at least "consumer" types (such as combi)) boilers are designed as "throw-away after a year or two". Probably radiators and piping etc of the same vintage were expected to last more than a fortnight or so!

It would seem that the only reasoning for constant replacement of heating systems is to attempt to conform to pressure from governmental-type bodies who like to control every little thing you want to do.

btw I have no objection to combi boilers where they are appropriate - I use one myself!

[jim]

//snip//

would endorse that.

It is certainly true that semi-clogged up old rads won't be a joy to a new boiler, but don't let anyone persuade you that clogged up rads will have a major effect on your fuel costs.

A new boiler might - just might- give a fuel efficiency in the upper

80s% whilst an elderly one might be nearer 80%. However the cost of new boiler might take you many years to recover from lower fuel bills.

Impression I've formed from lots of half heard conversations is that new boilers have a life of only 15 years.

[Fred]

If you reduced your bills by 20% per year, how long would it take to pay back replacing the boiler? If it's more than 5 years then I'd not bother. You might well have to replace the boiler within this time or at least have it repaired. The radiators will be fine. Replace a leaky one when it leaks. Do you have thermostatic valves on your radiators? If not then if it was me I'd fit some - but again you might to check the sort of saving vs reduction of gas and possibly increased comfort.

[meow2222]

As long as its not a 55% efficient one I'd keep it. Consider yourself lucky.

If you did fit a new one, could the old one be left in situ so it can be used again after the new ones dead and buriable? Just curious.

NT

[johnbrian.lacey]

Thanks for those comments, all very helpful. Just one point that perhaps can be answered, how do you come to a figure that indicates the efficiency of a boiler ?

Thanks

Brian [e-mail] wrote:

[Roger]

The message from [e-mail] contains these words:

See

table on the first page gives a general indication of the savings to be had and to my mind suggests that on cost grounds it is probably never financially advantageous for most people to replace a working gas fired boiler as the undoubted savings in gas costs will not exceed the capital cost of the replacement (and its probably higher maintenance costs) before the new boiler with its built in obsolescence reaches the end of its economic life.

The best condensing boilers (as can be seen on the next sedbuk page) are marginally better than the table suggests and as your boiler is so old it could well be 55% efficient (or even less) so yours could be one of the few cases where new will produce a saving. However the chances are that as condensing boilers need larger radiators to allow them to operate at their most efficient you would need to factor in the cost of the whole of a new heating system or accept that your savings will not be as great as sedbuk predicts.

No doubt if Dribble is around (I have him killfiled) he will have claimed you are financially inept (or worse) for not having spent £2-3000 on a newer boiler long ago, but economics is one of the many subjects that Dribble just can't understand.

[David Hansen]

On 4 Sep 2006 16:57:48 -0700 someone who may be [e-mail] wrote this:-

I almost did the same when I replaced a mechanical programmer with an electronic one at least a decade ago. The electronic one failed after about five years, at which point I took the mechanical one out of my "might be useful sometime" box and put it back on the wall. The mechanical one is still working.

[jim]

A meter tells your this via a probe put in the exhaust gas.

The meters need relatively expensive regular calibration which is why you may find a direct answer is avoided.

Standard equipment for servicing - ask what the % is next time you have the boiler serviced.

[mcbrien410]

Surely the mucky water can be replaced with clean water by simply flushing? I do my 23 year old solid fuel system every two years. Turn all radiators OFF except one, turn pump on high speed and continually drain the system. Do this sequentually around the house starting upstairs. It takes a week or more for the water to become de-aireated again but generally that only effects the upstairs radiators.

Chris.

[John Rumm]

I am not convinced that is going to be true most of the time. You need to consider that modern boilers are modulating and will adjust their flow temperature so as to achive good efficency regardless of radiator sizing. The only time this will not be true is when the outside temperature is so cold that you need to run a higher flow temperature in order to get the house warm enough.

However, that does not change the sums much, so you still need to do them to work out if there is any advantage to a premature replacement.

[<me9]

A system with a 55% efficiency boiler will be so old that it will have been designed without much insulation to the building. It is unlikely to require larger radiators to operate efficiently with a condensing boiler, as in most circumstances insulation/draughtproofing will have been fitted over the years. If not, now would be a good time to do it.