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Lead lag set-up for two steam boilers??
Recently a client of mine had her 600,000 btu steam boiler replaced. The contractor, not me, installed two 300,000 btu burnhams. He told her that the boilers were set up so only one boiler would run, and if necessary the second on would kick in if needed. Both boilers piped into same 4" header. A quick look didn't reveal any special controls, tekmar etc. There's a single thermostat in old large house.
Is it possible? I've never seen it done without actuated valves with special controls etc..
Nothing like this on this system. House is vintage 1910.