The Trion TTM was made in the 60s and there are no longer parts available for it. It was replaced by the Trion TTM II and then the Trion TTM III. Parts are available for from us for both of them on the appropriate pages of this site. Eventualy this series was replaced by the Trion HE2000 and the Trion HE1400. Below are links to the HE1400 and the HE2000 which are the 2 recomended factory replacements for the TTM series. The one you need would depend upon the capacity of your air conditioning system. Systems that are 3.5 tons and smaller should use the HE1400 and systems 4 tons and larger should use the HE2000.