Focus Van Heater Issues

[focus van]

Hi all

Model : Focus 2008-, 1.8L Duratorq-DI HPCR (115PS) Lynx,

Having an issue with my van. Heaters are very slow to blow hot air. Then when i am moving and have the revs up it blows hot air just fine. Come to a stop in traffic and at idle it goes back down to cold air again.

temp gauge on the dash is reading mid way as normal.

I'm thinking my thermostat has had it.

Had a quick search and cant seem to find a guide on changing it.

Any other common issues which could be causing it?

[AdeMk1]

Air lock, blocked heater matrix or could be the Water Pump. Impellers probably broken so doesn't really pump water around the engine/heater very well at idle.

[focus van]

Cheers AdeMk1

Just to add if i hold the rev's above 3000 for a bit the heaters start blowing hot air

[focus van]

And it gets weirder. Just out for a 30 minute ish drive there. Came back and noticed some steam coming from drivers headlight area. Popped the bonnet and yip it was steam. Investigated further. Expansion tank for coolant is empty!!! . Looked even more. There is my coolant! on the plastic covering at the bottom of the engine! it would appear i have a coolant leak.

After driving the expansion tank should drop below min a bit anyway?

When the car is cold ill top it up to the minium level again.