These logs are about 20 yrs old. I removed them from my parents home when I had to replace them to sale their house. They worked great until I brought them to my house. I have been told I need to replace the regulator. I have no idea where to start. The logs are still functional. Do I need to replace the unit the logs sit on? Or just throw them out and buy a new entire set? If I can get them working for a couple of hundred dollars it would be worth the trouble. Thank you!