Just pulled this morning after a small battle, been noticing a slight coolant leak for months that was sporadic. Finally hunted it down to either the heater valve element or hoses.

This sure looks like rust - can the element leak or just the hose/connection?

Pirk,
My Daimler Double Six 1993 had the same symptoms; sporadic coolant/water disappearance that I could not trace to any hose. Super frustrating.
It was definitely the unit/element.
Mechanic disconnected it and all has been fine. Looking to get another element/unit/valve at some point, but heating is not a big priority in Hong Kong.
Charles

I have replaced this part before. It is not uncommon to get a leaking part, brand new.

someone on this forum, I believe recommended an alternative plastic part, which I purchased later, but never installed. I will eventually install it, and will report back.

If no one chimes in with the part number, I’ll post back when I get a chance to find it.

If you’re ordering parts to Hong Kong, I’d imagine the plastic part looks to be the safer part.

The hot water valve there can very definitely leak. I had that problem with my car--with the heater on there was a definitely cascade of coolant from it. Solved by getting a new valve. Metal, not plastic. Works perfectly now.