Hey folks, new guy here but looking for some assistance. I'm a general contractor and having some issues with a natural gas Trane package unit at the shop. Model # 4YCC3030A1075AA, Serial # 9193H8G9H. It's used in a storage area to just keep things above freezing during the winter and occasionally cool and remove some excess humidity during the summer. The furnace did fire up this fall and seemed to heat, though maybe a little cooler than normal but I can't say for sure. However, the other day I noticed it wasn't heating (people are not in that area regularly so not sure how long it had been malfunctioning) and started to diagnose the problem. I thought I'd give it a whirl at fixing before calling the HVAC guy. When calling for heat, the combustion fan motor will turn on but I never hear the gas valve "click," no igniter, or anything similar to indicate it even tries to light. The CFM LED does flicker when it is running, though I don't know if that is normal or not. Per the diagnostic LED, it is showing a "Pressure Switch Problem." After doing some searching online, I tried a few things people suggested, but it appears to me that this unit has significantly different characteristics since it is a package unit. Some people talked about a clear tube from the pressure switch that can become clogged or even blown into to, I guess, simulate high pressure. There is no tube anywhere near this switch as far as I can tell. Does not appear to be any blockages on the combustion fan from what I could see. One of the things I did try was disconnecting and then jumping across the pressure switch terminals but it still threw the same code. Does anyone have suggestions on where to go from here? Thanks! bjepple

Hello all, I searched the forum best I could to see if anyone had issues with this particular unit heater but no luck. I live in northeastern michigan, so yes we have cold winters and I wanted to install a heat source for my garage during those cold winter months. So long story short, my wife's cousin gave me a Trane Model GP-155C Unit Heater that I have been trying to get running. I'm not sure how old it is but I'm guessing at least 20 years since I can't find info anywhere on the web for it. Supposedly it was ran on propane for a number of years. Anyway, at first I couldn't even get the pilot to stay lit but I managed to figure that out after testing the thermocouple and cleaning it. Now my problem is that I can't seem to get the Basotrol solenoid to open and actually fire up the furnace. I assumed maybe I needed to wire in a thermostat but not sure where to even start with that because I can't find any info for this particular heater. I'm sure it's simple but I'd rather ask someone familiar with it than rely on guesswork. Currently the blower (fan) has a dedicated AC power chord attached and then there is another power chord that is wired in. The fan works when plugged in but nothing happens with the second plug providing power and the pilot lit. Sorry if I am not proving enough info or using improper terminology. I have attached a few pictures that hopefully will help. ​​​​​​[url=https://postimg.cc/R6h5sWqr][/url] [url=https://postimg.cc/23SMxNvv][/url] [url=https://postimg.cc/xqp7xpyZ][/url] [url=https://postimg.cc/4Hy04pZw][/url] [url=https://postimg.cc/bDzMMKB7][/url] [url=https://postimg.cc/RqP5rZ9X][/url]