I would appreciate any observations from the members of this excellent forum.
I had a Viessman W-100 open vent(non combi) boiler fitted 4 weeks ago. This replaced an older condensing Vaillant open vent boiler which was very quiet. I have noticed that when the boiler fires up, on occasions but not always, there is a dull 'thump' sound with the gas being ignited. On shutting down there is a 'tinkling sound' akin to metal contracting. I contacted Viessman who sent a technician around and replaced 2-3 parts - gas valve, PCB unit etc. Everything but the heat exchanger in fact as he said it could be a number of components causing the issue. I think the term is delayed ignition. He also checked the gas pressure which was fine delivered along about 8 metres of 22mm pipe from the gas meter narrowing to 15mm about 4 feet before entering the boiler. Exactly the same set up as the Vaillant open vent albeit the viessman is 16kw compared to the 15kw output Vaillant. Now I realise that sound is subjective but the firing up and shutting down on the boiler cycle is quite intrusive. Although when the boiler is in burning mode it is indeed very quiet. If anyone reading this has the same boiler I would welcome your thoughts.
I had a Viessman W-100 open vent(non combi) boiler fitted 4 weeks ago. This replaced an older condensing Vaillant open vent boiler which was very quiet. I have noticed that when the boiler fires up, on occasions but not always, there is a dull 'thump' sound with the gas being ignited. On shutting down there is a 'tinkling sound' akin to metal contracting. I contacted Viessman who sent a technician around and replaced 2-3 parts - gas valve, PCB unit etc. Everything but the heat exchanger in fact as he said it could be a number of components causing the issue. I think the term is delayed ignition. He also checked the gas pressure which was fine delivered along about 8 metres of 22mm pipe from the gas meter narrowing to 15mm about 4 feet before entering the boiler. Exactly the same set up as the Vaillant open vent albeit the viessman is 16kw compared to the 15kw output Vaillant. Now I realise that sound is subjective but the firing up and shutting down on the boiler cycle is quite intrusive. Although when the boiler is in burning mode it is indeed very quiet. If anyone reading this has the same boiler I would welcome your thoughts.
