No idea! I can't see any hoses that look like that in any of the Lings diagrams.
I'd have thought a heater bypass (especially seeing as it's called a "bypass hose"), but I can't see a bypass circuit. Mine just looks like this under the bonnet ... with the two inlet hoses (with the valve in-between) being the ones I've ordered ...
Looks like the culprit is to be found on the H23 ...
The 1990 Accord 2.2 (F22 engine?) looks like it also has this hose, running at the back of the stat housing ...
So ... as far as I can see (without going out and looking under the bonnet), this hose has nothing to do with the H22a.
