Photo may vary slightly — verify by part number before ordering.AP411-3 — WaterFurnace AlpinePure Filter Systm 036-38 24x27.5x4 MERV 11
WaterFurnace has discontinued part AP411-3 with no direct replacement listed. Send us your model and serial and we'll find the current alternative.
Ask about alternativesOverview
WaterFurnace AP411-3 — AlpinePure Filter Systm 036-38 24x27.5x4 MERV 11. A filter removes dirt, moisture or contaminants from the air, refrigerant or oil passing through it. Also written as AP4113.
Discontinued by WaterFurnace — no direct replacement listed. Contact us with your model and serial number and we'll find the correct current-production alternative.
Fits this WaterFurnace unit: SDV038B121CTLAP (1 model; the Fits These Units list below is complete). These are the units we've confirmed — not necessarily the only ones. Send us the model and serial number if yours isn't listed.
Genuine WaterFurnace OEM part — not an aftermarket substitute.
What is WaterFurnace AP411-3?
It is a genuine WaterFurnace OEM filter, listed by WaterFurnace as “AlpinePure Filter Systm 036-38 24x27.5x4 MERV 11”.
Which WaterFurnace units use AP411-3?
Confirmed fits include SDV038B121CTLAP. The Fits These Units list on this page shows all 1 confirmed model.
Is AP411-3 still available?
Discontinued by WaterFurnace — no direct replacement listed. Contact us with your model and serial number and we'll find the correct current-production alternative.
What are the signs a filter has failed?
A clogged or saturated filter may restrict flow, raise pressure drop or let contaminants through.
Is AP411-3 a genuine WaterFurnace part?
Yes. AP411-3 is WaterFurnace's own part number for this item (also written AP4113), and this is a genuine OEM part, not an aftermarket substitute. Search or order by this number.
How do I confirm AP411-3 fits my unit?
Match the part number on your original part, or check your unit's model against the Fits These Units list on this page. Not sure? Send us the model and serial number and we'll confirm before you order.
Fits These Units
Confirmed to fit the WaterFurnace units below — and these are not the only models this part fits. Contact us for the entire compatibility list, or if you don't see your unit, send the model and serial and we'll confirm before you buy.
- SDV038B121CTLAP
Specifications
| Part Type | Filter |
|---|---|
| Filter Rating | MERV 11 |
| Qty per Unit | 1 |
| Condition | New — Factory OEM |
| Availability | Discontinued |
Ask the Parts Desk
Not sure this fits? Need more than what's in stock? Send the model and serial from the unit's data plate — a real person reads it and confirms before you order.
Common Questions
Is the stock number on this page real?
Yes — it's the live count from our own shelf, not an availability estimate. If it says 1, that's how many are physically here. When it hits zero, this page says so.
Is this a genuine WaterFurnace part, or aftermarket?
Genuine WaterFurnace OEM equipment sourced through WaterFurnace's authorized parts program — not an aftermarket substitute.
How do I confirm this fits my unit?
Match part number AP411-3 to your unit's parts diagram. If unsure, send us your model and serial number and we'll verify before you order.
What's the warranty on this part?
Warranty terms vary by manufacturer. Contact us with your order number for details specific to this part.
How fast does this ship?
In-stock items ship the same business day on orders placed before 1pm ET, Monday–Friday. Standard ground delivers to most of the continental US in 2–5 business days. Ships via UPS/FedEx Ground, or truck freight for oversized items. $15 flat-rate shipping, free on US orders of $50+.
Does everything ship UPS or FedEx Ground?
Most orders ship UPS or FedEx Ground. A small number of large or heavy parts across the catalog ship by truck freight instead, and we reach out to arrange a delivery window before those orders leave the warehouse. Oversized items that ship by truck freight are also covered by free standard shipping on orders of $50 or more.
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