New Yorker boiler AP 590 winterizing question

[George Gilbert]

I have a New Yorker boiler AP 590 that is oil based burner, primarily used for heating my hot water, but when I am away I use it to heat my home too. This winter planning to be away a bit and typically we get colder temperatures. So I am going to empty my water pipes and blow compressed air in it.
I did have my boiler guy put in antifreeze in it to winterize . But this is my question, when I empty my hot water pipes and blow air in it, will it affect my boiler? Since it’s a separate loop I am guessing not, but if the loop is empty, will the boiler temperature gauge think it needs to be heated and run non stop? Cause it’s tankless coil heating. I am confused as whether I should leave my water on so not to affect the boiler.. or can I go ahead and empty my pipes and leave water off in house. I plan on leaving my thermostat set on to 50 deg. Thanks for help

 

[Dana]

That's a quite a lot of boiler for just heating hot water. An oil-fired water heater delivers a lot better hot water service.

The boiler's temperature isn't sensed at the tankless coil, rather the sensor well is behind the aquastat control. Running with a dry tankless coil won't affect the boiler.

If the low limit has been set to 160F or something so that the tankless provides reasonable hot water service that temperature can usually be backed off to 140-145F, which lowers the standby loss to the boiler room. With it cranked up for serving hot water the boiler room will usually be the warmest room in the house. Backed off to 140F it'll still be the warmest room in the house, but not as warm. If the boiler room is in an uninsulated basement the additional heat loss out of the house of that extra-warm uninsulated space can easily be 10-15% of the total fuel use.

The tankless coil isn't going to freeze unless the power goes off for days, but if you're keeping the house at 50F for freeze control the pipes can still freeze elsewhere in the house much more quickly during an extended power outage, so it's prudent to drain it. Put some plastic food wrap over the toilets and bath/sink drains to keep gases from backing up into the house.

 

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[George Gilbert]

Thanks Dana. Boiler is in uninsulated basement. I plan on emptying all my water pipes just in case of extended power outages. I will go ahead and empty my hot water pipes and not worry about damaging coil, since no hot water will be used.

 

[Dana]

Thanks Dana. Boiler is in uninsulated basement. I plan on emptying all my water pipes just in case of extended power outages. I will go ahead and empty my hot water pipes and not worry about damaging coil, since no hot water will be used.

At some point it'll be worth insulating the basement, given the price of oil and the relatively cool outdoor temps in ME. If it's a poured concrete or concrete block/cinder-block foundation it can be a pretty cheap DIY using roofing foam reclaimed from commercial building re-roofing & demolition. If it's quarried stone block, brick, fieldstone, or rubble foundation it's a bit more expensive often requiring spray polyurethane foam.

 

[George Gilbert]

At some point it'll be worth insulating the basement, given the price of oil and the relatively cool outdoor temps in ME. If it's a poured concrete or concrete block/cinder-block foundation it can be a pretty cheap DIY using roofing foam reclaimed from commercial building re-roofing & demolition. If it's quarried stone block, brick, fieldstone, or rubble foundation it's a bit more expensive often requiring spray polyurethane foam.

Thanks Dana,
I had another question, I am planning to blow compressed air in my water pipes so as to avoid freezing if prolonged power outage. Since my hot water comes from the same boiler as my heat for home, introducing air in pipes will cause any issue in heating with my hot waterbaseboard? I do plan to empty my hot water pipe and empty the coil, as I won’t be using hot water while away. But my boiler will be running to heat my house.

 

[Dana]

The tankless coil is a heat exchanger that keeps the potable water separate from the heating system water. If it's dry on the potable side it doesn't affect the performance of the heating system side.