BOSTON -- Climbing oil prices have some homeowners considering a switch to another heat source.

"The industry is under siege," said Mike Ferrante, head of the Mass Oilheat Council.

As of last week, the Scott-Williams oil company was charging $4.20 a gallon for home heating oil. It's tough news for homeowners and oil dealers alike. Dealers are watching customers slip slowly but surely toward natural gas, despite up-front conversion costs of $5,000 to $10,000.

Massachusetts oil dealers are coming together, to fight back. "The key things are our efficiency, high technology equipment, warmth and comfort and dependability from your local dealer. You get that," said Ferrante.

Last winter the average New England family, with an average size home, paying the average state-wide price, spent $430 a month to heat with oil. Compare that to $266 a month for electric heat, and $206 a month to heat with natural gas.

"Well, price is certainly not, not are our advantage right now," said Ferrante.

But a Goldman Sachs report earlier this month predicted that the amount of natural gas available this fall to heat our homes could be "seriously low." Electric companies say their supply is good, even during the summer's peak demand and beyond. Oil supplies are strong, too.

"There's no shortages at all, anywhere," said Ken Williams, owner of the Scott-Williams oil company in Quincy, Mass.

Price predictions are up for oil, natural gas and electricity. OPEC and Goldman Sachs predict oil could top $200 a barrel by next year.

"This is a bubble," said Williams. "And much like the dot-com bubble of the 1990s, it's bound to end."

History is on oil's side. For most of the last two decades, oil prices have been far lower than gas or electricity, and a government energy outlook for the year 2030 predicts the price of oil could fall to $70 a barrel again.

Bottom line? Most experts say homeowners should not switch to a different heating source based on price alone.

"What people can do is conserve," said Ferrante, "And they can certainly upgrade older systems. Those are two things that will save you money."