This is something of an update to a previous discussion here: http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15542&page=1#Comment_265315

I wrote to the suppliers of the Morso DB15 and heat store in June last year, the outcome f which is that we've just had an MCZ Gardenia Hydro pellet boiler stove fitted - I think pretty much at cost price, with the company paying for the installation at no cost to ourselves. So, a pretty good outcome and it means we're still getting all our heating and hot water from renewables.

It's early days, so there's probably still some tweaking to be done on settings but we're not getting the output per kg that was predicted. The output is metered and it's a small hopper feed with bagged pellets so I know how much we're getting per kg. The performance estimate was just under 4kWh per kg (3.96) but we're actually only getting just over 3kWh/kg, which obviously makes running costs considerably higher.

Do any of you know why this might be? We've reduced the pellet dosing as far as possible (-30% from default) but it doesn't seem to have made much difference to the output, though the brazier and glass are staying cleaner. I think the company are going to check the flue draft as well - if they haven't already - as I understand that can make a difference.

Do the pellets (all EN plus A1 and BSL certified) vary much in heat output from one manufacturer to another?

Regards,
Ian

Pellets only have to meet a standard, we started out using blazers as they were the closest producer, persevered with them but they never burnt that well created an acrid smoke and too much clinker. So then tried some Land Energy followed by Sparkletts, all bulk blow loads. Land energy burnt the best by a fraction over the Sparkletts but would happily use either.