A comment
I heat the house in two and a half floors with an area of 250 square meters. The boiler is in the basement, the pipe from the boiler to the chimney 1 m is 150 mm, then a brick chimney 10.5 m high, 1 m above the roof ridge. Dual-circuit system. Primary circuit: boiler - a boiler for 1300 liters. The second circuit is a boiler - 26 steel batteries from one collector and 10 branches of a warm floor with a total length of 480 m - from another collector.
During operation, contradictions were found out: the ignition modes are a shock for the boiler. It should work at a temperature in the return of 65 g (however, it pretty well pulls already at 45-50 g). On the other hand, regular cleaning is required, especially of a hard-to-reach place between the second and third heat exchangers, where a special cover is installed. (She, by the way, does not fit tightly, makes it possible to suck in air, which worsens combustion. I had to seal this cap to death with heat-resistant sealant, and clean it with an old vacuum cleaner, which is no longer a pity!) That is, good once every three to four days it is necessary to stop the boiler and clean it, and not work continuously. At the same time, the boiler returns to normal mode only on the second day, when the boiler is fully warmed up and the heat removal from the batteries and underfloor heating is reduced. That is, a couple of days you heat everything, the day works fine, fuel consumption drops ... and then you need to stop it, let it cool and clean!
pros
Just incredible survivability! Boiled away three times without consequences. Once boiled away with a complete power outage and the termination of the circulation of the coolant. At the same time, he went on self-acceleration. From a high temperature, a thermometer with a manometer and a draft regulator fell out ... The blow-out skewed and the boiler began to suck in air intensively ... Upon arrival of the firefighters, the whole boiler was red and it was impossible to approach it closer than a meter ... Let it cool, checked for leaks , repacked threaded connections, straightened skewed parts, changed thermal insulation - it works! Not as glorious as we would like, but pretty well!
Minuses
Very gentle on traction. Almost what’s wrong - immediately the smoke from under the boot lid.