Today's gas boilers in are much more efficient and versatile than equipment available even 5 or 10 years ago. Many have efficiencies that are greater than 90% and may be eligible for rebates or tax credits. New systems can work with existing or new steam, hot water baseboard, radiant, or air handler systems. If you own a home or business in Williston , VT call Vermont Energy Contracting & Supply Corp. to either service your existing boiler or install a new high efficiency gas boiler.