Another leaking unvented system!

[moonlight]

What cylinder is this? I don't recognise it and I don't see any pressure relief pipework for the heating? PG1 looks like its for the heating. Is there an expansion vessel for the heating somewhere? I can only see one for the water.

 

[joeirish]

What cylinder is this? I don't recognise it and I don't see any pressure relief pipework for the heating? PG1 looks like its for the heating. Is there an expansion vessel for the heating somewhere? I can only see one for the water.

It's called a Latento. Attached is a better photo showing the pressure vessel. 35 litre volume. The way it works is that the thermal store holds 500 litres. This is what heats the water in the DHW and UFH coils. The boiler flow and return are also connected to the ufh manifold which is not in these photos but is in one I posted yesterday.