The house I recently acquired has a Thorn M54 boiler which I want to move to a more out-of-the-way location in the same room. It's a floor-standing boiler and I'll have to butcher my kitchen units in order to reloacate the boiler. I realise this would be the perfect opportunity to buy a modern wall mounted boiler, but frankly, I don't have the spare cash. So my question, really, is: how many more years of life will I be likely to get out of this Thorn M54 boiler? I gather spares are getting more difficult to obtain as it's about 30 years old...
When I bought my house in 1982, it had a M54 that had been converted from town gas to natural gas as the town gas parts were stacked up beside the gas meter. I don't know how that old makes it but it is still going strong 28 years later. Our gas bill is still not excessive so I can't see me replacing for some time to come.
I've taken the casing off and built it into a kitchen based unit with a suitable thermal lining and ventilation.
I've had no problem with spares but it has hardly needed any. Universal thermocouples fit it and I made an electronic igniter out of a motorbike coil for it when the naff piezo pilot lighter failed 25 odd years back. The pilot jet clogs up now and then but soaking it it in acid soon clears it and I have a spare one that I keep clean ready. To be honest it is so simple that it would easy to repair with improvised parts. I service it each year but if I were to get BG or similar in they would possibly find some reason to condemn it.
How long is a piece of string? I would go with Bob - it's a good, well made boiler. Move it and see how it goes. Little to lose except time and some inconvenience in the worst of cases. Nick.
Sort of, but it's easy to be blinded by such exaggerations. "Twice as much" would be 100% more, but in fact 91 is only 65% more than 55. So it should reduce your annual fuel bill by only about 40% (as opposed to 50%) if you switched to a modern boiler. Against that you have to set the cost of acquiring and installing the new boiler.
Let's pluck some figures out of the air. If your gas bill is £1200 a year, the modern boiler would save you some £475 a year in fuel. If the boiler costs £2000 to put in, that means it would take more than 4 years to pay for itself.
These modern things are more complicated than the nice simple old ones which "last forever", and this means three things: (1) More goes wrong with them, (2) You can't fix'em yourself when they go wrong, (3) They're not designed to last very long.
(1) and (2) probably mean you'd have to budget for a maintenance/service contract where you needn't have bothered before. That might set you back £250 per year, which brings your annual savings down to £225 a year, and increases your break even time to nearly 9 years.
(3) might mean the damn thing's expected life is only 10 years.
So until your existing one starts showing signs of giving up the ghost, don't even think of replacing it.
The trouble with the official list is that if the boiler hasn't been tested they assign it a value of 55%. It doesn't necessarily mean it is 55%. The manufacturers data for mine states 82% but the official figure is 55% because its too old to have been tested.
What it means is i could potentially save about 10% of my gas bill, That would be about £40 a year and it would take an awful long time to repay the cost of an expensive, probably unreliable condensing boiler. Even if it saved the full amount its would still take years. It just isn't worth replacing it with a potentially unreliable boiler, and they are far more complex and do fail more often. I have had one fault in about 30 years with the Thorn one I have.
I agree the official efficiency figure is not brilliant by modern standards but even knocking 40% off by gas bill is unlikely to make it worthwhile changing until it is impossible to repair it. Given the typical life and high maintenance/ cost of spares of modern boilers. I suggest you hang on to it.
Ronald Raygun wrote in news:CrZoo.11222$ snipped-for-privacy@newsfe23.ams:
That's very helpful - thank you. Thanks in particular, for elucidating the real implications of that percentage figure. I have to say, this was the advice I was hoping to hear. I installed a combi boiler in my last house and it was constantly giving problems requiring expensive maintenance. Meanwhile, the old 1970s system boiler in my parents' house kept purring away, decade after decade, never needing the slightest attention. They had a contract with British Gas to send an engineer around once a year to check the system. Needless to say, he always tried his utmost to get them to scrap that excellent boiler and buy a new one!
The 65% figure refers to old light weight boilers where mine was a top of the range new fangled combi one at the time so likely more efficient
If I divide the nominal heating capacity by the nominal heating input I get a figure of 75% but not sure if this is a valid way to get an efficiency figure
Against my current gas usage it would take many years to recover the cost of a new boiler, I estimate around 15 years and as modern boilers appear to have only a 10 year life then I would be even less like to recover the cost
I bought the boiler in 1986. I think it cost around £400 to buy and I fitted it myself with a qualified central heating engineer to check my work so it really owes me nothing
All that I have had to since is replace the automatic air bleed which cost £19.00 and pump up the expansion vessel and that only last week
Almost anyone would save more cash by adding insulation before a new boiler (especially as it subsidised). I cut my heating bill to about £25 pm so there is no way I would ever get the cash back on a modern boiler replacement. I am thinking about ASHP as a replacement as I can cool in the summer then. The odd few days a year where it below freezing outside i can get around with a hosepipe as I don't have a water meter. ;-)
Of course adding insulation is the best option as it covers global warming and global cooling and staying the same. You can't really lose by it at current prices. Shame it wasn't so cheap when I did mine 30 years ago, however it has paid for itself many times and is still earning now.
I used to have a Glowworm Galaxie back boiler and gas fire, installed in 1979 and only recently left behind in a house move. About 10 years after installation the BG tales of woe started: 'can't get spares', then 'flue has no plate', then 'the ventilation is insufficient'. I ignored it all. Apart from cleaning out the jockey tank once a year and adding new inhibitor, it never went wrong. It kept our modest semi warm even without the gas fire on - we could get the open-plan lounge to 23 degC while it was -5 outside. The last 12 months running costs (including the coldest winter since the boiler was installed) for CH and DWH were just £500. One of the chaps who came to service it said his dad had one and it was 43 years old and had never gone wrong.
Much is claimed for the efficiency of modern boilers, and I'm sure that the boiler part is very efficient. However, boilers are used in systems, and the real question is the efficiency of the system.
My airing cupboard was warm, from the lagged tank, CH piping, and chimney breast. All the 'wasted' heat was going somewhere useful, and when snow covered the roofs, there wasn't a large clear patch round the chimney.
My view on your question is to keep your old boiler, find out what spare parts are available for it, and in the fullness of time decide what you want to do about it. You might be surprised by overall running costs being pleasantly low, and the possibility of servicing it yourself.
All models are "quality". It's just than some qualities are higher than others.
Of course it isn't. If they were built to last, then once everyone has one, the manufacturers would go out of business because then nobody would need to buy any more of them!
I fitted one 4 years ago, and I'm very pleased with it. It gets used for heating and cooling when I'm working at home and just need to heat the one room where I'm working (probably 95% heating, 5% cooling).
It's on a power meter which has been running for 3/4 of a year now. It's used 103kWh in that period.
Actually, it works fine below freezing. It's when it's between 0 and about 6 outside that it struggles, because thats where ice forms on it, and it has to run defrost cycles, and it's probably no better than an electric heater when doing that. (Good fun for generating big clouds in the garden though.)
You really need to DIY it though. The cost of a professional install will more than wipe out any savings you'll ever make, just as with most green initiatives.
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