EKO 25 questions

[singe]

Hi Everyone,

Ive recently Installed a Orlan Eko super 25 in my parents old house to replace an aging gas boiler. The house is big, and the heating system is all 2 1/2" steel pipe with big old cast iron rads about 15 in total. We plumbed it straight in, no storage via a laddomatt mixing valve set at about 71 C. There is a separate pump to circulate through the heating system at a reasonable speed.

The chimney is about 35' and 16" square brick lined from an old coke boiler attached via 3' of 8" flexi at a 45 deg angle. The idea of running no storage was to save money and that the Eko 25 could run flat out most of the time being a smaller boiler (incidently the return temp has never been over 50 degrees C) Fuel is mostly soft wood billets approx 4"x4"x3" basically offcuts from pallet manufacture that we get free, moisture content varies from 15-40%

This boiler has smoked since install a few months ago, there is always some smoke coming out of the chimney. Ive checked the primary and secondary air settings and altered them (reducing the primary) to no avail, the fan cover is at about 10% opening, anything more and it burns way too quick, a full load will burn out to nothing in less than 2 hrs. I was sure the boiler was actually leaking at one point although the only evidence of this was the smoke! and checked down the exchanger tubes, there were large coals that had been pulled up these to the flue exit. Is there too much draft on this setup messing with the air settings?

I have a EKO 25 in my shed with 2 meters of twinwall flue that heats pools of water to grow coral, I use the same poor quality damp fuel but get great gassification (whole lower ceramics glowing inc door) absolutely no visible smoke out of the chimney, burn times of over 2 hrs and outputs of between 15- 28 kwh (depending on dampness of fuel)... again there is no storage, boiler heats pools via undefloor heating and heat exchangers so it rarely idles if there calling for heat, in effect there 25,000 liters of heat storage! Im just wondering if these differences are down to flue hight or something else

cheers

 

[Nofossil]

Could well be too much draft. Rules vary about barometric dampers on solid fuel appliances, but that might be the solution.

 

[singe]

cheers. Theres an opening in the base of the chimney stack (flue from boiler enters about 5ft up) thats sealed off, obviously originally used for cleaning purposes, I was contemplating installing a sliding vent here operated by a lever from the boiler house next door. Having it closed when loading to keep the smoke out of the boiler room, then opened up when running the boiler to lessen the draft. anyone done anything like this?

 

[ihookem]

If you have two and one works, on doesn't it is in the flue unless there is something wrong with the stove itself.. I would say nofossil is right. 35' is a long flue.

 

[Gooserider]

I agree, it sounds like excess draft to me as well... However I would not attempt to do a manual control if the rules allow you to use a barometric damper - put a tee on the back of the EKO, with the stack connection out the top and the baro out the bottom... There are then charts you can use to set the weight on the baro to give you the desired flue temperature. It then will self adjust to give you the right draft on a continuous basis.

The other item you mentioned is the return temp - I hope that is just the temperature coming back to the boiler from the heating system, and it's getting raised by the Laddomat before actually going into the boiler? Otherwise it sounds like you'd be on the low side for your boiler return protection....

Gooserider

 

[singe]

Hi, cheers for the replys.

Return temp is over 70C so mixing valve doing its job

I cant install a T at the back of the stove due to a space issue and the weird angle on the flexi to connect to the old boiler chimney

Yesterday I opened up a 2" square hole in the cleaning cover at the base of the chimney stack (this is about 4' below where the stove pipe enters in the side) air is whistling through this hole like mad when the boiler is in operation so it surely should be reducing the pull on the boiler? anyway the end result is the boiler still smokes like a good one, burns wood real fast and does'nt give off all that much heat! From what ive seen up the chimney there are a lot creosote deposits (after 2 months burning), again my boilers 2meters of twinwall are practically clean after 8 months of operation.

Primarys 9 mm, secondary 3.5 turns out (counting from when you first meet resistance screwing it in as there pretty flimsy) fan opening 10/15%

Any ideas anyone? This weekend I think im going to reduce the draft to practically nothing, ie fully open the hole up in the base of the chimney and see if this changes anything, otherwise im stuck for ideas.