Fixed! The diaphragm had a tiny split this part was only two years old too.
So really happy as no need to drain down etc, and the best bit is I had a spare diaphragm so cost to me was zero! My 11 year old lad was keen to help and learn about boilers so managed to turn a chore into a pleasure...
Ok will check diaphragm first, wishful win. Followed by diverter replacement, again!
Thanks to all for this great forum and the expert help from those who know and take pride in what they do and give up their free time to support others, much appreciated.
Jim (wannabe plumber).
Ok tried the flow demand seems to be around 6 l/m however did manage to ease the tap gradually to full without the boiler even coming on! So it looks more likely to be a sticky diverter valve, or perhaps diaphragm issue.
I have seen it is possible to buy the diaphragm or the interns (moving...
Thank you for this steer, this is something I had not considered but makes a great deal of sense.
I don't believe I have any non-return valves in the system but two upstairs sinks and the shower have mixers, with the shower being non-thermostatic type. I can easily isolate the main sink hot...
Scratching my head here.
Boiler is fitted down stair , heating is fine.
Down stairs Kitchen DHW works fine.
Upstairs sinks and shower are cold
Upstairs bath is hot..
When upstairs sink tap or shower is turn to hot the white lever on the diverter valve moves slightly but not enough to...
Thanks for your response,
I have replaced the whole diverter valve recently, not just the lever.
If I need to remove the whole diverter first to replace the switch lever then I will check the diaphragm first. Many thanks.
Had a similar problem on this boiler before, where the divertor valve was replaced (just a few years back). The only problem then was the switch lever had broken. I have recently discovered this lever can be bought as a separate item.
My suspicions this time is:
1. The switch lever has again...