Thank you Gents for your replies.
From what you say then gas pressure is lower for heating than for hot water? That makes sense.
Tony-Sorry if I offended you by saying “plumber” and not “heating engineer”. Personally I have great respect for Plumbers but the word engineer is over used...
Well folks having read some extremely helpful advice on this site I wonder if I anyone could kindly help me so I can sound knowledgeable when the plumber turns up . Other posts don't seem to hit my problem.
I have a combi boiler- Vaillant turbomax plus 828E (VUW GB 282/2-5) about 7 years old...
