Thanks for your thoughts Alan, it's always useful to get an opinion from someone who's got the same device
It's possible that i've been using the wrong size sealing rope - not having any better info to go by i've just been using the same size as was fitted when I got the boat, but there's no guarantee that the previous owner had it right! I've just measured a spare a spare bit of what I have at present and it's about 7-8mm in 'unused' condition. Looking at some new stoves in the chandler's earlier, most of them seemed to have bigger seals than i'm using, but that could just be down to them being different design. Not sure if it shows very well, but photo below shows door with present seal
The photo below shows a 'side-on' view with the door closed where you should hopefully be able to see the gap - I reckon it's about 2mm. As another indication of the wear this stove seems to have suffered, you can probably also see that part of the edge of the groove that the seal sits in has also disappeared.
I'm not sure if it's entirely original, my catch looks like this
I had to replace the bolt that forms the adjustment about 3 years ago as the old one broke when I tried to adjust it! Tightening up the catch might not be that simple anyway as there's an issue with the catch as well, which also dosen't help the situation - there is a LOT of play in the shaft of the catch. If you pull the top of the door outwards when in the closed position, there is enough play to allow a significant gap to be created at the top, see photo below.
I haven't managed to get a picture that shows it properly, but i took some measurements earlier. Measuring the thickness of the front plate away from the edge of the opening it appears to be about 4mm thick. However, the part of the front plate that the door closes onto around the edge of the opening is about 2mm - so it appears that i've lost about 2mm of thickness where the door seal meets the front plate!
I could get a new door (for £85!) which would resolve the issue with the catch and then with a bigger seal it might seal OK for a while longer. However, given the degree of wastage my feeling at the moment is it would only be prolonging the inevitable and it might be better to put that money towards a new stove!
Looking on midland's website (to get the price of a door) i've noticed that you can just get the doorknob and catch for about £16, so I suppose I could try fitting a new catch and bigger seal and see if that works for now.
hmmm .... any thoughts as to best course of action anyone?
Peter