I would have thought if the continuity checks out on the gas valve, the engineer then tested the pcb? All content copyright solv group | web design by. I don't have vinger to mix or soda plz help what else can i use? Do plumbers offer a written warranty? Eor heating are also qualified to install liquid petroleum gas boilers. With state-of-the-art technology, to find cracked pipes is simple! Plumbers, gasfitters and drainlayers need to have. Questions? comments?.