Is there a maximum height a floor standing boiler Can be Off the floor.
We have always Installed on a 4 inch or 6 inch pad.
Because of all the floods one customer has asked We install 18 inches off the floor
Never done this, but could not find anything to prove it could not be done.
Depends. Is it steam or hot water? How how is the ceiling? Hot water...no problem. Steam...potential problems. You need to maintain some critical dimensions with steam. For either, you need to ensure proper vent connection pitch.
EK boilers must be close to that with the stands. I had boilers in attics due to location. As long as it is safe/secure, and all relief valves piped to code, and unit can be serviced, I can't find anything. I have always installed on 4" solid cement blocks. If it is a flood zone, check with the building dept.
As long as the boilers supported properly on a stable base, (non-combustible), there is nowhere that says you can't raise it to the ceiling, as long as piping things mentioned above are not an issue and proper clearances are kept.