Both of the lines that are lit up are flexible aluminum couplings. They're required in some areas as the final connections to the appliances. They're in line with cast iron gas pipe and fittings. They are much more thin and way better at conducting heat.
Both of the lines that are lit up are flexible aluminum couplings. They're required in some areas as the final connections to the appliances. They're in line with cast iron gas pipe and fittings. They are much more thin and way better at conducting heat.
Source: former HVAC tech