Hope this isn’t a re-post but I don’t see my earlier response on the board yet. Anyway..
Thanks for the advice. I’ll give it a try since the heater hasn’t been flushed in the two years it’s been in service. I didn’t know that was recommended but I see it is now after exploring this and other sites. However, I am wondering whether sediment could explain all the symptoms I note. Also It did drain well when I changed the relief valve. I didn’t notice any sediment then.
Any other thoughts on how to proceede if there is no evidence of sediment?