I have a problem with the above boiler on the hot water side, when you call for DHW the boiler fires up OK in low burner but then stays in low burner with the temperature lingering at about 55 degrees c (control set to high). After maybe 2-4 minutes (period of time varies) the burner comes on full and the temp rises to 80 degrees c, then boiler modulates down and burner shuts off. Also sometimes DHW wont come on at all and CH seems to running fine.
I'm starting to think PCB or gas valve but have very little experience with Vaillant, what does the vast experience and knowledge of the forum think?
Thanks in advance.
I'm starting to think PCB or gas valve but have very little experience with Vaillant, what does the vast experience and knowledge of the forum think?
Thanks in advance.
