Plumber was due to come at 8.30 and he did. Hurray! Now a process of trial and error to find the problem. The shower definitely needed new sealant so he did that. If there's a problem with the toilet as well he will have to take some tiles off the wall as its a concealed cistern and so he can’t reach anything! Am keeping my fingers crossed that the new sealant will have sorted it. He also cleared another partial blockage in the bathroom shower and had a look at the toilet which has a very weak flush. He thinks some of the water jets are clogged with lime scale so have ordered some narrow brushes and gel to try and clear them. If it doesn't work it may need to be a new pan. Apparently I should have been flushing the toilet every couple of days as it is rarely used.
It was another grey and drizzly day so I decided to give the house a really good clean and do some smallish tasks which had been on my list for a while. Went for a short damp walk at lunch time and rather wished I hadn't. The cats seemed keen to be out though!