Why not go for the Santon Premier from the same website.
I have fitted a few of these and have been suitably impressed.
IMHO I think Megaflos are over rated.
Graham
The Gledhill is a good cylinder, I'd take it over the Santon. The Santon has a 10-year warranty, Gledhill has a 25-year warranty, this says a lot about a manufacturer's confidence in their product. Of the two I'd go for the Gledhill; not just because of the warranty, although that's a consideration, but it is also much more efficient as it loses much less heat over a 24/hr period than the Santon, meaning it needs reheating less often. This ultimately reduces fuel bills.
Personally I like the OSO Super S cylinders - 25-year warranty, they look very tidy, are exceptionally easy to install with all the connections on the top, and blow both the above, and just about everything else as far as I'm aware, out of the water on heat up and reheat times. Heat loss is worse than the Gledhill but better than the Santon.
As for whether there's much difference, there is a bit. As I've mentioned, some cylinders have longer warranties than others, some lose more heat than others, some heat up faster than others, and some are easier to install than others. Not a fan of the HS Megaflo, it's the most well known but not really the best for a few reasons.
However Miljee, before you go and buy any unvented cylinder you MUST check your incoming supply is adequate for an unvented cylinder. It is not simply a case of putting one in to get better flow/pressure, your supply needs to be able to keep up with demand. Most cylinders require around 20 litres a minute flow with 1.5 bar dynamic pressure as a minimum (Gledhill actually recommend 25L/min on theirs). You will almost certainly need a 25mm or larger incoming main to achieve this.
Hope this helps
