A comment
OK-15 boiler, in operation for 4 years, 3 heating elements of 3 kW each are built in, a 9 kW control panel is installed. Considering that I live in a garden, where at a load of 6-7 kW per house it is not possible to use other appliances, I consider the use of heating elements to be useless. When two heaters are working, the boiler gains a temperature of 55-60 degrees, which is enough to maintain heat (the house is well insulated), while the same light installed in the boiler room shines twice as bad as usual.
I usually drown with wood, the size of which really needs to be selected, periodically I use coal, from which there is a lot of soot and a specific smell. I bought RUF briquettes (65 rubles a pack, a pack of 12 pieces) and Pinky Kay (75 rubles a pack of 12 pieces) from the use of which I was satisfied, the consumption of firewood was 2-3 times more. When buying a boiler, I purchased a pellet burner (not automatic) and a 35 liter tank if I am not mistaken. A tank full of pellets, which is about 35-40 kg, lasts for 30 hours, while the temperature in the boiler is more than 70 degrees (depending on the grates available in the configuration, the temperature can be maintained from 50 to 90 degrees).
Given the cost of high-quality pellets (without bark admixture), about 160 rubles per 20 kg bag, the operation of the boiler becomes not very profitable. Currently, I burn cut pallets in the boiler, which are available in sufficient quantities, using RUF briquettes in parallel. In the 2-3 day absence in the winter, the house cools down to 13-14 degrees, while living I support 24-25. I live in Yekaterinburg. I hope someone comes in handy if you ask questions. Py Sy: by example: a house of 95 Sq., 2 floors, 1 floor foam block, 2 floor beam, insulated with high quality.At a temperature outside of -20, I start to heat the boiler from 8 am and finish at 23, the briquettes will leave 1.5 packs, pellets 15-17 kg, coal, to which firewood has to be mixed periodically, because for some reason, it burns badly, it takes 10 kg, the number of firewood (pallets) is not realistic to calculate.
pros
boiler price, purchased for 19,000
Minuses
terrible (not economical and not efficient) work of built-in tenov