Expansion tanks

[davidbrady]

Al,

The Mach 5 Headhunter pump will work with or without an accumulator tank. Mine doesn't have one. I've had cycling of my Headhunter pump which I traced to a small water leak at the Aquahot. Where the fresh water enters the domestic loop at the AH there's knurled plastic fitting that gets hand tightened. The only way to really tighten it is to remove the Webasto burner. Another possibility is the check valve coming off the high pressure side of the Headhunter pump. If that leaks it can bleed water pressure off and cause the pump to cycle. My money is on a small water leak somewhere.