Hi, I am going to "sod it all" and fit a complete thermostat housing.
There are however two real options, I can fit the same type (03C121111B) that has a single thermostat, or I can fit (in theory) another (03C121111AB) that has two thermostats.

Would it be ok to fit the two thermostat one?

Ta muchly in advance, Reg

Your car is not suited to a dual-circuit version, I believe.

1 minute ago, Breezy_Pete said:

Your car is not suited to a dual-circuit version, I believe.

That's a bu@@er, why do so many sites say that it fits?

No idea. Lots of parts look-ups are very poor.

This is a screenshot showing the correct part (or sub-parts such as the thermostat itself and its o-ring seal).

1 minute ago, Breezy_Pete said:

No idea. Lots of parts look-ups are very poor.

This is a screenshot showing the correct part (or sub-parts such as the thermostat itself and its o-ring seal).

I know, it actually looks like it'd fit, but knowing me it'll destroy something else if I went ahead.

Shame, because it's cheaper!
(Why are thase silly thermostat's soooo pricey when you have to assemble them yourself?)

Plenty of pattern parts priced in the teens of £s, doesn't seem mad-expensive to me?

03c121110a for sale | eBay

5 minutes ago, Breezy_Pete said:

Plenty of pattern parts priced in the teens of £s, doesn't seem mad-expensive to me?

03c121110a for sale | eBay

I think I might take the "coolant regulator" out tomorrow and see if anything's untowards in there!

Why not wait until you have a replacement ready to fit?

1 minute ago, Breezy_Pete said:

Why not wait until you have a replacement ready to fit?

If the thermostat's ok, then it'll need the full housing etc... (It's difficult enough as My other half is getting cold towards me as it is!)

The thermostat is the only thing that can go wrong really, apart from the coolant temperature sender. Everything else is just inert plastic.

I think I'll just buy a pre-used assembly for about a "Placido"... (Tenor)

But the thermostat element in that may well be as dead as yours?

If yours is original it has done 18+ years service, remember.

If it is, they'll refund my moolah!

6 minutes ago, Breezy_Pete said:

But the thermostat element in that may well be as dead as yours?

If yours is original it has done 18+ years service, remember.

But not your time.

Your choice.

I've managed to get a complete housing for seven of our British quids, so I'll see how it goes!