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Honeywell Temperature Regulator circa 1924 for 2 pipe steam
Had a to replace a bad tstat for my last call today and was pleasantly surprised to find this antique Honeywell control hanging on the wall near the boiler. Owner said the original boiler was coal converted to oil and then replaced 20 something yrs ago. I’m guessing this was a damper control for the coal? This thing had two batteries a little bigger than a can of soda