Low boy
The old unit was the same way, I know, it is a little close. There is enough room to remove burner, but if the heat exchange needs replace I guess the ducts would need disconnected. I was there today and started installing oil lines I did the the easy one first. I am installing some nice bracket mounted gerber screw filters with check valves,shut off valves and relays that power a oil booster pump in the front part of the basement. I unfortunately didn't get to finish, I had to go to another job. Ironically I expect that will be the first unit to need a heat exchanger, because that is the one of the two that had giant holes in the combustion chamber. Yesterday we had a passing thunderstorm an noticed water in the flue pipe, the flue runs out the back of the house and up the outside wall in b-vent. The vent has a chimney cap. I'm having the flue replaced or repaired, one or the other. I let the owner know that warranty would be void with out it.