Our water runs lukewarm for 10-15 minutes before getting hot. How can we fix it without replacing the oil burn?

The oil burner is operating, heat works fine. Seems we are wasting alot of precious oil.Our water runs lukewarm for 10-15 minutes before getting hot. How can we fix it without replacing the oil burn?
I would insulate your pipes if they are accessible. Long runs will cause heat loss before it gets to the tap. Not much else can be done in an old house that's economical.Our water runs lukewarm for 10-15 minutes before getting hot. How can we fix it without replacing the oil burn?
depends on how far the water has to travel , to the faucet,


the only thing i can think of is to insulate the pipes, turn the Temperature on the heater up


or install a loop pipe [keeps the hot water running all the time in a Circle ]
Insulating the pipes will help if you run hot water frequently enough to keep the water in the pipes, and the pipes warm. Eventually it will cool, even with insulation - it will just take longer.