Hi, we have a valliant boiler that has recently started to hiss about every second.
The boiler's stat has always been set to full (position 9). When up to temperature the flames go out and the hissing stops. When hot the pressure gauge rises to 1.5bar.
Any ideas why this is?
Here is a picture of our ancient boiler...
The boiler's stat has always been set to full (position 9). When up to temperature the flames go out and the hissing stops. When hot the pressure gauge rises to 1.5bar.
Any ideas why this is?
Here is a picture of our ancient boiler...