[77newell]

Sean: I have two two lines running up the inside of the right frame rail and two other lines running up the inside of the left frame rail. I assumed that each side constituted a single circuit. One hose in each circuit connects to one of the lower shutoff valves and the other hose in each circuit connects to one of the upper valves. Where I could go wrong in my assumption is if one of the hoses crosses over to the opposing side somewhere forward of the rear axle where I haven't gone yet. Each of the hoses running up the right frame rail are tapped off for the under-bed heater.

Your configuration could well be different but this is how my coach is plumbed.

Ken: I used the same company as a source for the boost pump I installed on my 77 coach which seemed to never have had one, but thanks for the reminder. The pump made a substantial improvement in heating output.

You two guys are always a great source of help and I appreciate you both.