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Gas hot water boiler short cycles
Our gas hot water boiler has been short cycling and I can’t figure out what’s wrong. It started more or less after I replaced the original Honeywell thermostat with a programmable Honeywell thermostat, so I spent time there first. Nothing seems to make a difference on that end.
Boiler is a Weil McLain, 1985 vintage, single-zone, gas boiler feeding 7 rads in a 1,500 sq. ft. house.
It kicks on, fires up and the temp. Gauge will rise from 140 to 160 and then it shuts down. This takes about three minutes. Pressure is at 15 throughout.
I pulled the two rubber vacuum hoses off and cleaned some soot out, re-siliconed the box they plug into and connected everything back up. No change.
When I connected the thermostat, I wired it wrong at first, and I’m wondering if that might have ruined the vacuum switch or something else?
Running out of ideas.