We have a new home (1.5 years) with gas WH. When awoke this AM no hot water pressure from any tap on main floor or lower level (cold was fine). Opened and closed most of the taps in the house on both levels but just a dribble or nothing. Then suddenly a loud "clunk" and now pressure is fine. Assume the noise was water hammer as I had relieved pressure by turning on and off the taps.
This is quite a mystery as I wouldn't think we would have had deposits clogging the line in only 1.5 years of use. But I'm at a loss as to what else it might have been.
By the way, the temp here in the Twin Cities dropped to 15 below last night, but that has happened earler this winter and last.
If you think it may have been deposits, is there something I can do to flush them out to avoid future clogging?

Any thoughts?

More a frozen pipe some where.

More a frozen pipe some where.

I thought of this possibility, but how to explain many other sub-zero nights since moved in and no problems. You obviously think this more likely than deposits being as the home is this new?

I found the outside combustion air flex tube outlet into the room (for the furnace) terminated at just 2 inches from the hot water line from the WH. Last nites outside temp was 15 below zero. I suspect this cold air at least caused slush in the line which then fairly easily broke free with just turning on various taps. Seems like my plumbing sub-contractor should have known this. Thanks for your suggestion hkstroud.

Mighrt want to put a heat tape on that line if you are going to have much ot that kind of Artic weather.

Mighrt want to put a heat tape on that line if you are going to have much ot that kind of Artic weather.

Thanks, I just moved the flex tube so air flows into an area where there are no pipes. Thanks again.