As arranged, took Erin Mae round to Anglo Welsh. Keith changed the thermostat (£20) and gave the cooling system a check and a nod of approval. Looked at the toilet and its manual, and together we decided on replacing the non-return valve, which I ordered from Lee Sanitation.
Carried on down to Tixall Wide for lunch, where a friendly swan came up under the hatch. Engine temperature was normal, albeit this was a short run.
2 miles, about 2 hours engine, what with the testing.