Good point, I'll try that today. Usually if I left the tap at only full hot water, it would work and stay way too hot to actually shower on that. So when you start fiddling with the cold water trying to balance it out a bit, then it immediately would shut down. Nowadays it also shuts down even at full hot water, but I reckon the shower head might have something to do with that.
I sort of had the similar issue and thought the new installed town gas heater was mal functioning so called them up to check it again, the town gas guy came in, saw my shower head was one of those with multi massage type ones and he said they are not good so he took it off and showed me that my water heater works perfectly. the guy was in and out of my house in 5 mins LOL he told me to get a regular shower head which I did and works perfectly.
For what it's worth we've had the same issue over the last few months. Towngas just came to visit and it turned out there was a water saving device in the shower head. This was slowing water flow and causing the issue.
Did you adjust the temperature? The Towngas technicians previously told me that the way to get the heater to work is counter-intuitive - you want to turn the temperature up to the highest, and then reduce the gas flow valve. This tricks the water heater into keeping the fire on
So...seems you were right, turning the heater to 60ºC makes it work stable...But scalding hot. If I want bearable water, I need to turn the handle a bit past the middle between the hot and cold, leaning on the cold side...and then it turns off again
So...I still might need to call the towngas guy. But thanks, at least now I know an emergency trick
You're almost there I think - the last step is the trickiest. Look for the gas pipe, usually in the middle. Turn the valve on it slightly closed and try the temperature again. If the heater doesn't turn on, you probably closed the gas too much.
If this doesn't work, arrange towngas to come along.