My four year old HVAC unit is getting stuck in defrost and I'm constantly having to switch to AC then back to heat so that the unit won't whine in defrost while it's heating.
I had a tech come out to my house to fix it and he deduced that the unit is getting stuck in defrost because something is, "gunking up the valve." I then asked if he would replace the reversing valve to which he replied, "It would put too much pressure on the rest of the system. You need a new system."
Why exactly can't the reversing valve be replaced? In my mind that's like saying, "your alternator is bad. you need a new car." Can someone explain this to me? Clearly there is something that I don't understand.
I found this video on YouTube - https://www.youtube.com/watch?v=k41tRTCHJ3I in which a tech replaces the valve.
A new reversing valve (I looked up the part) costs $125. A new HVAC system will cost $8k. I would happily pay a reasonable amount to have the unit repaired - I know it will be more than $125 obviously.
Edit: Yes, I called five other HVAC companies (on my honor I really did) over the course of the last two weeks trying to find someone that would be willing to perform the repair. Each time I explained what was occurring and how the valve was getting stuck in defrost and would they please replace the valve. Each time I was told, "no". They won't replace it. I needed to purchase a new system.