Heating Help

tank size for Buderus boiler

We have just installed a Buderus GB142 as backup heat for our 1800
square foot home. The main heat source is a pellet boiler. Our propane
gas supplier (Suburban)  has told us we need two 95 gallon tanks to run
the boiler properly. Is this necessary? Why two tanks? And is this size
necessary for backup heat?

That is the correct size.

It has to do with vaporization rate of the product.

The liquid propane inside the tank must vaporize to a gas before it is allowed to move through the regulator and into the piping system to be burned by the appliance.

Each tank is rated for a certain vaporization rate at a certain percentage of full at a given temperature. If you are in the upper Midwest or New England, that temperature is 0 deg or below. For a 100,000 btu/hr appliance and above, that means two PIGS as we call them.

You are receiving proper information. The side effect of only installing one tank is that the unit would probably lockup when you needed it the most. The great thing about propane is that it does not go bad and doesn't gel up like oil. So it can sit in those tanks for a long time with no side effects.