Would it be easy to tell by looking if the DHW heat exchanger was blocked, I removed it last night and ran cold water through it, it seemed very clean and flowed easily. It made no difference to the water temp though.
Last fault code is F 64 irreversible electronic system malfunction.
I...
Hot water is not getting hot enough.
Problem started 2 months ago when first thing in the morning it was cold then started to get hot then cold again. ( Boiler was switching on and off )
Usually after leaving it for 30 mins it seemed to be ok. Then it seemed to just get warm instead of...