A whole day putting everything back and methodically trying to ensure I dont screw up in my frustration.
Thankfully all seems, touch wood ,to be OK. I now have a very warm cabin, heater output is very strong. . Coolant level also holding steady, Run for about 40 mins mix of 30 mins idle and short drive , reluctant to chance my luck so late in the day .... come back home , can here hissing and bubbling within but everything appears OK.
Not counting my chickens just yet , but after a tough weekend with weather , frustrations of the task , I can now see light .... feeling I have actually made some progress.
Good News - The steam / smoke is gone,,,, now seems to be more like what you would expect with any other car, there for a few mins on start up then not really there or noticeable thereafter.
No signs of Mayo
A few learnings , thoughts on the task so far ...
Take photos before you start and as you go..., not that I had any issue , if you are doing this task over a few days ... it helps to have reference for which screw goes where , which cable , cable routing , how cables were fastened .
When putting the battery back together ensure the positive end is as far forward as possible , otherwise when you replace the cover you cant connect the posiitive terminal.
Bleed , Bleed and Bleed again, Three times at least
Dont rely on your pressure guage to be OK even if new.... Ended up getting a different set today as the one off Amazon was giving haphazard readings.
Use long nose pliers , and also a set with the tips at 45 degrees can be helpful.
The arch liners collect crap and that stored water ...so potential for rust points... take them off and give a good hose down maybe biannually ?
Took a while before I could get fans to kick in, maybe 30 mins ....
Can fully understand why no garage would want to do this job and would maybe overcharge should a customer want it done.
Find it hard to comprehend that all of the symptoms I had might have been down to the stat failing / failed.
and finally Thank you EddieJ for advice, tips and getting me to where I am now.
Parts I used
Napa 11846171RMP Stat
Coolant Thermostat fits PEUGEOT RCZ 1.6 10 to 15 NAPA 1336CC 9804315380 Quality | eBay UK
Coolant PIpe
Water Coolant Pump Hose Pipe Replacement for Peugeot Citroen Berlingo C3 C4 C5 DS3 DS4 DS5 Opel Grandland X Peugeot 2008 207 208 3008 307 308 5008 508 Partner Rcz 1351.VF 1351VF : Amazon.co.uk: Automotive
Harness
HouYeen Thermostat Housing Wiring Loom for P-eugeot 207 208 308 3008 C-itroen Berlingo C3 C4 Picasso M-ini R55 R56 R57 1.6 : Amazon.co.uk: Automotive
Coolant Mannol G12+
MANNOL G12+ Ready to Use Coolant Antifreeze, TL774D TL774F, 10 litres : Amazon.co.uk: Automotive
Cap - Febi
febi bilstein 37600 Radiator Cap for coolant expansion tank, pack of one : Amazon.co.uk: Automotive