What will happen if my boiler pressure is below 12 psi?
You haven't said the make and type of boiler. But I assume it's a combi. If it is you either omitted the decimal point or got the format wrong as combis display in bar not psi. So, most combis should be set at 1.0 bar or just above in the COLD state. If it drops to less than about 0.5 bar the boiler will not fire for safety reasons. When the boiler runs, the pressure shown will rise considerably. This is quite normal. Hope this helps.
