Andersen 100 vs A-Series: identify casement seal locations

Quick answer. For casement or awning windows, Andersen describes different sash weatherstrip arrangements for 100 Series and A-Series units. Start with the window series and, for A-Series, the documented production period—not with two strips that look similar. The 100 Series reference names primary, leaf and top-rail bulb styles; the A-Series reference names leaf and bulb styles. ¹²

The location comparison that prevents a false match

The manufacturer's A-Series source gives 2011 as a boundary but does not supply a precise changeover month in this evidence. A unit from that year therefore needs its own dated configuration confirmed. ²

Use two photographs, not one profile silhouette

Photo 1 — entire sash. Include the identifiable product-family evidence and the outside/inside orientation, with the window closed and accessible. Write confirmed series, window type, and manufacture period evidence in separate fields. Do not infer a series from a loose seal.

Photo 2 — contact location. Without removing material, photograph the sash top, each vertical side, and the opening/channel the suspect strip occupies. Then compare positions, not just cross-section drawings. On a confirmed 100 Series unit, distinguish the outer-side leaf from the nearer-interior top bulb before selecting a name. ⁴⁵

A decision you can make before purchasing

1. Series unconfirmed? Stop at identification. Different arrangement descriptions do not prove cross-series interchangeability.
2. Confirmed 100 Series? Classify the damaged location among its documented three styles. ¹
3. Confirmed A-Series? Check whether the appropriate original A-Series leaf/bulb distribution corresponds to the unit's period. ²
4. Confirmed component, uncertain part length or finish? The A-Series help page says its leaf weatherstrip is made for unit size, while its bulb replacement has listed colors and can be cut to fit. These are A-Series ordering statements only. ⁶

The output should be a series + sash edge + style + period + evidence record, not a claim that the seal on one series can replace the seal on the other. If there is no reliable series/date evidence, request exact-window assistance instead of fitting parts by visual resemblance.

Safety limit: This is an identification guide. Andersen's A-Series replacement page calls for removing the sash in its installation procedure, which must be handled under applicable manufacturer instructions and safe lifting/access conditions; do not treat a photograph checklist as a sash-removal tutorial. ²

Sources and references

All footnoted manufacturer facts were checked against the original publisher pages on 2026-10-11. A source describing a product family does not prove a specific unit or replacement fit.