Clogged Filters = $$

Cleaning a filter on a "No Heat" call. If the filter is clogged, there's no flow through the heater. No Flow=No Heat. We always ask, every single time, "Are your filters clean?". Uusally we get an "Of course" Followed by a big diatribe about thier uncles breothers cousins neighbor looked at it and said they need a 1000 dollar part....and the filter ends up being the problem. Save money. Clean those filters.