COVID-19 UPDATE: In accordance with current public health recommendations to practise social distancing and limit contact, we are temporarily providing emergency service only, such as 'no heat or hot water' situations. We will contact all clients to reschedule non-emergency work. At this time, fuel delivery will continue as normal, except delivery slips will not be left. A record of your delivery can be found in MyAccount or Online Banking instead of coming into the office. Thank you for your cooperation at this time!

small wilsons logo

Calisto Boiler

Oil Fired Hot Water Boiler - Convertible to Propane

The Calisto boiler is a powerful source of heating for all of the modern zoned heat delivery systems including baseboard, in-floor radiant, steel panel radiators and free standing radiators. The efficient three pass design on the Kerr Calisto boiler coupled with the hydrolevel fuel smart control will maximize system efficiency by constantly adjusting the boiler water temperature to best match the conditions inside the home. Reducing temperature swings, increasing fuel savings and providing years of reliable comfort for your home.

With boiler sizes ranging from 74,000 to 193,000 btuh, Kerr’s Calisto series can meet every home owners needs.


  • Up To 88.6% AFUE
  • Triple-pass design for increased efficiency
  • Chimney or direct venting
  • Cast iron
  • Cold start
  • Energy Star rated
  • Limited lifetime warranty