Is your heads giving you full bore?
This is the heads outlet hose we had on our Holman & Pye ¾-tonner Polar Bear until last year. In a recent survey I was asked when it was last changed, and I confessed that, in 18 years of ownership, I hadn't. He said it might be a good idea.
An unattractive brown filling dried to a bright white, and of course the heads now pumps a great deal better using the full 2in diameter of the new hose. Lavacs with their Whale Gusher pumps are underrated in my view, it is a miracle that it was still pumping out waste at all!
I thought it was interesting to see just what our lavatory hoses might be having to battle against. Miranda Delmar-Morgan