Why have you resurrected an old thread? They were definitely a good boiler, but not so good that their efficiency can increase with age. Your man is talking out of his proverbial. 
Netaheat 10/16E gas valve
- Thread starter loisj
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I take it he plucked that off his flue gas analyser?
I serviced some boilers today. My FGA told me they were 98%. Did I equate that to operational efficiency?
No.
Now, where was that CPA1 discussion again?
A 26 year old Netaheat will be unlikely to have 80%. Maybe NETT, maybe.
Why have you resurrected an old thread? They were definitely a good boiler, but not so good that their efficiency can increase with age. Your man is talking out of his proverbial.
Considering that this thread appears to have been running since 2004, and the post I answered was posted on 18th Jan 2011, I can't see how you can make remarks about me resurrecting an old thread. I never knew that there was a time limit on posting, or that my post would appear to get your back up. I thought I was making a valid point, and there was nothing in my post that was meant to cause offence or be the subject of the snidey remarks, that were also posted.
I trust my plumber 100%. I don't know of any plumber that would make a visit to my house, diagnose the problem, help me with locating the part, for which I had quotes up to £165.00, return the next day to fit the part, and only charge me £25.00. ( Ok. I know I have an annual service charge of £52.00 ). I'm happy that my boiler is working properly, and that I wasn't conned into forking out over two thousand pounds for a new system.
You know nothing at all about this particular boiler installation, and you may be generalising, but to cast aspersions on the quality of the work, or the standard or condition of the plumber's electronic equipment is totally uncalled for.
I take it he plucked that off his flue gas analyser?
I serviced some boilers today. My FGA told me they were 98%. Did I equate that to operational efficiency?
No.
Now, where was that CPA1 discussion again?
A 26 year old Netaheat will be unlikely to have 80%. Maybe NETT, maybe.
If a guy who hasn't seen my installation can quote 55% efficiency for ALL these boilers, really appears to have plucked this number from fresh air.
And I would be wary of a guy, doing a job for me, who doesn't trust his equipment.
Maybe I can put some perspective on this, which makes sense to me, but I'll let you experts decide for yourself. If you buy an item that has working parts, possibly a car, and the manufacturer says the car will do 40mpg urban, and you find you get 45mpg out of yours, could it possibly be that the manufacturer is erring on the lower side to cover any nit-picking. Know what I mean Harry?
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I know these boilers inside out and they were NEVER 80% efficient no matter what the installation configuration. That's all I was trying to say and if you take offence at comments on what you post then why so tetchy?
What was the point of your post? If you air your views on a public forum, then be prepared to be contradicted. If you don't like contradiction then..................
What was the point of your post? If you air your views on a public forum, then be prepared to be contradicted. If you don't like contradiction then..................
I guess you are just here for an argument. I would have been happy with a genuine intelligent response, but to say that ' Your man is talking out of his proverbial, ' is uncouth and uncalled for. I don't accept any remark like that has value, when I am trying to point out the technical issues with my boiler. If you think that I am tetchy, it stems from the fact that my input to the forum, simply stating the facts as they were told to me, seems to have had an effect on you, and therefore you think you have the right to abuse my plumber It wasn't something I made up, and I was not having a go at anyone. I was giving people the benefit of knowing that it didn't cost a fortune to get my boiler working again, and I wasn't conned into replacing it. I only took umbrage at your unnecessary offhand reply. Therefore I have a right to respond. My initial letter should have caused you no aggravation at all, and I can't understand why you have to jump all over it.
G
gaswizzard
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Or perhaps the test performed by the manufacturer is completely different than the one performed by yourself?
I often wonder how boiler manufacturers or test houses come up with efficiency numbers, some of the efficiency readings would make me believe they are testing in a Botswanan greenhouse with one radiator and the TRV turned to 1.
Seriously though, the efficiency test on an FGA is for the efficiency of the combustion of gas, not how effective the boiler is at using that perfect, or imperfect, burn to heat a water jacket.
Your boiler is putting out a healthy 80% combustion efficiency, Dan robinsons ones were putting out 98% maybe because they were condensing boilers and as such had lower flue temps giving better combustion efficiency. Obviously standing and running losses will contribute to the overall efficiency too and a lot of that obviously has to do with the design of the heat exchanger(s) and internal pipework.
In short the more heat the boiler extracts from the amount of gas input clearly means a better efficiency. Your boiler sadly has a lot of standing and running losses and so is likely to be far less than 80% overall efficiency. The exact number will be unknown to anyone, but a close guess can be taken from the SEDBUK numbers.
G
gaswizzard
Maybe your engineer failed to explain what the efficiency #s relate to when using a FGA , these boilers were somewhere in the region of around 70% efficient , this was a result of the cast iron heat exchanger coupled with the low CO2 due to shed loads of excess air in POCs.
The efficiency of a boiler is now measured as if it was in real use.
Its like the urban cycle on a car!
A constant speed of 56mph is not comparable with real driving.
I get 54-58mpg from my small car and thats with 60% driving in London!
Tony
Its like the urban cycle on a car!
A constant speed of 56mph is not comparable with real driving.
I get 54-58mpg from my small car and thats with 60% driving in London!
Tony
It appears we know more than you though doesn't it?
Seriously dude... you're onto a loser her. there is nothing wrong with keeping your old boiler going... just do so as part of an INFORMED decision using information that is correct.
80%
G
gaswizzard
Gotta love your smillies Dan.
G
gaswizzard
BTW Cooturkey , excess air in POCs is around 100% on the netaheats , not very efficient is it.
Or perhaps the test performed by the manufacturer is completely different than the one performed by yourself?
I often wonder how boiler manufacturers or test houses come up with efficiency numbers, some of the efficiency readings would make me believe they are testing in a Botswanan greenhouse with one radiator and the TRV turned to 1.
Seriously though, the efficiency test on an FGA is for the efficiency of the combustion of gas, not how effective the boiler is at using that perfect, or imperfect, burn to heat a water jacket.
Your boiler is putting out a healthy 80% combustion efficiency, Dan robinsons ones were putting out 98% maybe because they were condensing boilers and as such had lower flue temps giving better combustion efficiency. Obviously standing and running losses will contribute to the overall efficiency too and a lot of that obviously has to do with the design of the heat exchanger(s) and internal pipework.
In short the more heat the boiler extracts from the amount of gas input clearly means a better efficiency. Your boiler sadly has a lot of standing and running losses and so is likely to be far less than 80% overall efficiency. The exact number will be unknown to anyone, but a close guess can be taken from the SEDBUK numbers.
You sound well informed, and as an engineer, for a great part of my life, I understand what you are saying. My figures of 78% efficient come from the original manufacturers handbook. Now, it appears that ' efficiency ' means different things to different people. In general, if my car is more efficient than your car, or two manufacturers make a car of the same capacity, and one uses less fuel than the other, then that car is deemed more efficient. So the bottom line in terms of efficiency for the layman, means burning fuel more efficiently than something of the same capacity.
I am pasting a few lines below that were submitted to this forum by a chap called Chrishutt on the 3rd of Dec. 2005 :-................
No mention of Netaheats on sedbuk database that I can find either. Where do you guys get your figures?
The input of the 10 - 16 is 20.9 kW (max) and the output 16.1 (max), so it's notional efficiency is about 77%, which compares well with modern non-condensing boilers at around 80%.
The sedbuk assessment takes account of more realistic conditions, but it's hard to see how this could drop to 65%. I suspect the older boilers have been given an unrealistically low efficiency figure to encourage upgrading to condensing boilers.
So Chris's figure above, of ' notional efficincy is about 77%, tally's as near as dammit to the figures in my manual. ( 78% ). ' He also goes on to say that he can't see the figure dropping to 65%, which also confirms my thoughts on the 55% figure that I was quoting from the forum, and which also seems to have turned a frank discussion into an unnecessary attack of verbal abuse. And at the very end, I am inclined to agree with his comments that some people will talk an old boiler down, to encourage people to upgrade unnecessarily. My thanks to you for not losing track of my original post, and reading into it, something which was not there, or even intended to be there.
SEDBUK is a joke... It has a margin of error factored into it than blurs the boundaries between bands. The goal posts get moved around fairly regularly as well.
A couple of boilers were deemed too inefficient to be sold, then a few weeks later, the category was redefined and lo and behold... boilers back on the market
A couple of boilers were deemed too inefficient to be sold, then a few weeks later, the category was redefined and lo and behold... boilers back on the market
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