Flexible chimney rods rear flued stoves with liners

[Stu3k]

I've got a bit of a problem with the flue on our Esse. I'm not sure they did the best job on it (Hetas certified etc). We have a high ceiling and it's about 5 foot of single wall from the Esse vertically, then a 45 to the right. Then another 5 foot or so of single wall and another 45 upwards which is where it changes to SS double wall before it goes through the roof (single storey at this part of the house).

 

For a start I find it impossible to get a brush around the second bend, it snags on something. So I either have to dismantle the vitreous part every year or get up on the roof to sweep the SS part which just goes straight up about 20 foot to the ridge of the rest of the house. I have tried standard rods and brushes and even bought some white flexy ones with a brush with a ball on the end. I even trimmed the bristles on this one to make it more conical but no luck. The problem is that after the brush goes around the first bend, I guess it's then being forced against the bottom edge of the diagional pipe so has no reason to go around the second bend.

 

Couple questions really. Any ideas on how to get around this bend from below and also, should they have used so much single wall pipe? It's a pig to sweep as I guess it gums up more as it's colder. The SS stuff comes up shiny with a single sweep with a soft brush.

I drop a plumb bob down my flue attached to orange courlene ,then use that to pull thru 6mm blue poly rope , flue length about 7m , so pull about 8 down ,leaving same amount hanging out top and then make a snug-ish ball o rags and attach to rope ,close stove door and then pull up to top ,clean inside of stove and pull back down.Hey presto chimner swept and no scores on the flexible liner,Has added safety if it gets stuck, i'll just chuck a lit fire lighter down chimney and burn the rag ball out

[Stereo]

It's just getting up on the roof I'm not keen on. I don't have all the climbing gear and don't want to do a Rodd Hull.