Recent content by RogB

I don't know what the Burner pressure is, can I test? Sounds like a CORGI task.

Not sure I can tell you what type of DHW Heat Exchanger it is but it looks like an aluminium flask, approx 200mm high & 100mm diameter. Also ChrisR, I am very interested in your calculations can you explain in a little more detail how you got 29.5Kw input, the 13.25Kw for the water heating...

The boiler rating plate gives it as nominal input 35.5KW and nominal output as 26.6KW. As I have only recently moved in I have little history on the boiler but it was producing very hot water over the summer months. I appreciate that the cold water will be colder now but the difference is not...

I haven't got a thermometer available to me today, but I 'feel' no major difference. However when I reduce the flow rate too much the burner goes out. When the hot water is turned back on I get 'acceptable' hot water for a few seconds.

Thanks to everyone for their interest in helping me. With regard to the Gas usage, I did the test as you suggested. I have a metric meter and in a 2 minute period the meter went from 13.0 to 22.2

The NTC was also replaced as part of the diagnostics, but made no difference.

The DHW flow rate is approx 10L per min. The CH pipes do not get hot when hot water is being demanded, so this this prove that the divert valve is ok? How about the pump?

If I reduce the flow of the hot water the Boiler will eventually go out, but the temperature does not increase. It looks like the circulating water from the main heat exchanger has reached its temperature and turned the burner off

I have a Vaillant VCW 25 Combi Boiler. The CH is working but when the hot tap is turned on, the burners fire-up and remain burning until the demand for hot water is terminated but the water out of the tap is only 'luke warm'. The diaphragm has been changed by a plumber but it had no effect. He...