The best replacement for boilers is water heaters.

The best alternatives to boilers are rated as following:
★★★★★  water heaters
★★★  furnaces
★★  gas boilers
★★  non condensing
★★  worcester bosch
★★  combi
★  oil boilers
★  steam boilers
★  steel boilers
★  weil mclain
★  williamson boilers
★  non condensing boilers
  tankless water heaters
  vaillant
  water tube boilers
  hot water heaters
  burnham
  cast iron boilers
  heaters
  alternative water boilers
  hot water boilers
  mid efficiency boilers

Your alternative for boilers is not listed? Suggest!
Speaking about boilers, one probably shouldn't forget about stainless steel heat exchangers.

Other search terms related to boilers and their ratings are:
★★★★★ stainless steel heat exchangers
You have in mind a companion for boilers and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of boilers in all years. Click on graph for more.
boilers
water heaters
furnaces