We have a Lennox high efficiency gas furnace. When it was first installed, we had a (metal) electronic filter on it. This worked well for several years. A while back, when our AC gave trouble, the tech who fixed it told us that the electronic filter was not the best idea and recommended that we switch to a Filtrete high performance filter that reduces allergens. We have been using the Filtrete for just over a year, changing it every 6 months.
This week, the tech who came to service the furnace told us the furnace was over-heating and that the Filtrete filter was to blame. He said that the Filtrete filter is very dense and deeply pleated to catch as much dust and allergens as possible. This denseness prevents proper air flow through the furnace, therefore the furnace works too hard. The furnace over-heats, which shuts off the gas and the house is then not properly warmed up.
This made some sense to us as we had been finding the house getting quite cold sometime in the early morning hours, even though the furnace appeared to be working.
The tech suggested that we use a different type of disposable filter. Filtrete is quite expensive - the tech told us to get a less expensive pleated filter which would allow air to flow properly.
At this point, we are confused, as the Filtrete came highly recommended. Does anyone have any experience similar to this with Filtrete? Can you recommend a filter we should try? Very much appreciate any advice you can give.