How can i tell if thermostat is stuck open?

[barnpot]

Without removing the thermostat?

Engine taking a long time to warm up. Think thermostat might be stuck open.

thanks,

david

[barnpot]

Great, thanks, sounds sensible.

[barnpot]

Good to know, thanks

[barnpot]

So i tried this. The hose into the top of the radiator got hot after about 5 minutes.

Is that normal?

david