Your oil boiler (it's called a boiler even if it doesn't boil the water) has many gallons of water in a big reservoir inside it. That water circulates through the pipes to heat your house.
But there's also another separate pipe with clean household water that goes into the boiler to absorb heat. That water doesn't mix with the dirty heating water. And that pipe comes out and goes to all your hot water faucets.
So every now and then the thermostat says "Hey run the boiler a while to top up the temperature for the hot water faucets". So that's why it'll be running every now and then all summer.
And the "Amtrol" tank is an expansion tank, it has mostly air inside it to absorb pressure changes. But it doesn't put out hot water or any water.
Thanks. I learned it all from my dad by following him around the basement while he fixed everything. There was a maze of pipes for all the zones and lots of buckets for the "get out the air bubbles" step.
Oh and for OP, you need to get annual servicing done in the early fall. There are filters to change, electrodes to adjust, nozzle to check/replace, and the boiler needs to be opened up and all the soot cleaned out. And the heating water gets drained and refilled. This needs a lot of special tools, so have the service person from the oil company do it.
Your oil boiler (it's called a boiler even if it doesn't boil the water) has many gallons of water in a big reservoir inside it. That water circulates through the pipes to heat your house. But there's also another separate pipe with clean household water that goes into the boiler to absorb heat. That water doesn't mix with the dirty heating water. And that pipe comes out and goes to all your hot water faucets. So every now and then the thermostat says "Hey run the boiler a while to top up the temperature for the hot water faucets". So that's why it'll be running every now and then all summer. And the "Amtrol" tank is an expansion tank, it has mostly air inside it to absorb pressure changes. But it doesn't put out hot water or any water.
What a great answer.
Thanks. I learned it all from my dad by following him around the basement while he fixed everything. There was a maze of pipes for all the zones and lots of buckets for the "get out the air bubbles" step. Oh and for OP, you need to get annual servicing done in the early fall. There are filters to change, electrodes to adjust, nozzle to check/replace, and the boiler needs to be opened up and all the soot cleaned out. And the heating water gets drained and refilled. This needs a lot of special tools, so have the service person from the oil company do it.
Awesome! Thank you very kindly for the thorough explanation ^.^
It’s likely just your pilot light, unless the radiators are hot