sime friendly E ignitor?

hi,my above boiler (don't know age etc,was in when moved) when stating up c/h in morning,the ignitor? repeatedly clicks, then fires,stops,click,fires repeatedly,sometimes 20 times! is my ignitor for the c/h buggered? water is fine.i noticed,when touching the front panel dial(left knob) for temp control effects the ignitor (loose/faulty?) if running,and knob touched,it sometimes cuts out the heating? thoughts....tia