This filter fits to replace a WaterFurnace filter dimensions, but is NOT an OEM Replacement (which we have been unable to source because of the odd size).
e 59P509-04 is manufactured by Airguard for WaterFurnace and is considered by WaterFurnace to be the OEM replacement MERV 11 air filter for all their Geothermal Comfort Systems that use a 24 x 28 x 2 pre-filter.
The replacement filters used with WaterFurnace units that use a 24 x 28 x 4 pre-filter must use a filter that is a full 24" x 28". If you use a smaller filter such as many of the 23 1/2" x 27 3/4" filters sold by other manufacturers, your filter will not seal properly and you could get unfiltered air leaking around the edge of the filter, this is called bypass.
The manufacturer suggested replacement interval is 4 to 6 months, depending upon conditions and lifestyle.
This package ships in 6 to 8 weeks with 4 filters.
We apologize for the cost of Shipping. If you are ordering multiple cases (highly recommended), please call us and we'll adjust the Shipping Cost (our software doesn't do this automatically).