Main vent air flow sound after boiler stops?

datawaym8

I notice as soon as my boiler stops running, one of the main vents(Gorton 1) has this sound of air escaping.

This didn't happen during warmer days when my boiler didn't have to run every hour. But now when it's cold, my boiler ran for 40 mins, stops, and then runs again in 30 mins or so. I am guessing it has to do with too much pressure but makes me wonder if this means if the main vent is broken?

Jamie Hall

Is it air escaping? Much more likely to be air entering -- which would be quite normal. However, it does suggest that possibly your pressure is a little high...

datawaym8

Jamie Hall said:

Is it air escaping? Much more likely to be air entering -- which would be quite normal. However, it does suggest that possibly your pressure is a little high...

The boiler runs at lower pressure. Can i assume the problem is the frequency for repeated call for heat at such short duration? Also, it seems like the radiators and the pipe becomes cool in like 30 mins or so.

Jamie Hall

The time to cool down sounds reasonable. So does the cycle timing overall for cooler or cold weather.

Most vents will make some noise -- though usually not much -- when they reopen after the boiler shuts off. You can check to see if it is air being sucked in (much more likely) by holding your finger over the vent opening when it is doing it and seeing which way the air is going.

If it has only recently started doing this -- didn't do it last year, for instance, it is possible that it is slightly hung up. In principle, they can be cleaned (boil in vinegar and water) though I've never had much luck with that.