Nominal efficiency of the Sine 18 was 75%, but you have to take account of the partly wasted heat input of the permanent pilot and standing losses from air circulation through the large balanced flue, so maybe 70%? I doubt if www.boilers.org.uk bother to do a calculation for such an old boiler.
I would have expected the efficiency to be around 82% based on its design and constant firing. However the PP and open flue will reduce its seasonal efficiency and perhaps the 75% takes that into account!
The oldest one I have seen is about 25 years but the number is a bit different and its an open vertical flue instead of a balanced one. Almost all I see are about 1986/87 perhaps BG were installing them then.
If the wax capsule has lasted 20 years then I dont see that as poor engineering when the boiler was probably only expected to last 20 years.
Oldest one I still look after is from 1982 - still going strong.
Half the Juniors I installed a couple of years ago have developed leaks around the pump unions. I changed a 24i PCB this week - the flame sense was playing up after 18 months (it had also had a warranty callout from Worcester to repair a leek).
The 28i junior isnt condensing or are you talking about the new greenstar junior?
I also happen to think after working on Sine 18s for 17 years that they were and still are a good boiler.
Very often slated by those who misunderstood them.
I always check the wax capsule with a simple check of the preheat facility and watching the flag. Early diagnosis of no preheat can avert bigger problems when the capsule or more to the point a seized push rod stops completely.
I would have expected the efficiency to be around 82% based on its design and constant firing. However the PP and open flue will reduce its seasonal efficiency and perhaps the 75% takes that into account!
No it doesn't. The 75% figure is based on its input (26 kW) and output (19.5 kW) as stated in the MIs. I was surprised that it wasn't around 80% too. The Sine 18 is the balanced flue version of the early VCW T3 Ws. The other two were open flue models, the 20/1 and the 25/1.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local