Is this sound a leak? When can I refill

leaking

Weil Mc lain 6/23 after running for 20 minutes when cooling it sounded like water dripping on hot metal. It got slower as it cooled. I don’t remember the sound last year but I’m not sure . I recorded the sound but could not figure a way to include it here .
2nd question. I am flushing it tomorrow, how cool does it have to be for refill. About how long does it take to cool enough? Room is 70, water temp 70. How do I measure temp to know it’s cool enough? I have an IR thermometer, and fans to help cool. Suggestions on refilling would be appreciated. .

The drip noise and sizzle sounds like a drip is hitting the burners when shut off about once a second and reducing in frequency as it cools, maybe it just contractions ? What do you think it is ? Could I slide a piece of cardboard over the burner after it’s shut off to see if it gets wet? I don’t know not being there if there is any room to slide it in.

EdTheHeaterMan

I have posted a video on facebook then posted the facebook link to click on. But that was 20 years ago. there are several ways to link videos here. YouTube is a popular one.

As far as a Weil McLain 6/23… is that the date it was installed? Is that a model number of an old coal fires conversion from the 1930s?

Do you know if your boiler is a steam boiler or a hot water boiler?

Do you know the model number of the boiler?

can you post a photo of the boiler from far enough back to see the pipes from the floor to the ceiling that are connected to the boiler?

leaking

it’s a Weil Mc lain LGB 6/23 steam in 12 unit installed about 11 years ago . It’s run to about 1lb, blow down until clear about twice a week. Flushed yearly . Maybe 600,000 btu

HVACNUT

Flood the boiler.

leaking

what do you mean “flood boiler” fill it way up to see if water drips when cool?

leaking

pipes are all insulated with thick fiberglass .