After Texas deep freeze, no hot water from heater.

Specifics: Honeywell controller, pex piping and manifold, pilot lit, burners come on as temp control increased, pex from heater to manifold is warm to touch, plenty of pressure of cold and hot at the faucet.

Water from hot side of faucet is cold with random bursts of warm water.

Thoughts?

newer water heaters come with " heat trap" nipples.
there may be debris stuck at the hot outlet nipple ?

Thanks. After reading past posts, I am thinking my dip tube is compromised. The heater is in the attic where there were below freezing temps for several days and water was cut off. I didn't properly bleed lines so I am thinking dip tube froze near top and burst. will check this afternoon.

If the dip tube broke you would get hot water as soon as water that has cooled in the pipes is flushed, but the hot water wouldn't last long because cold water would be pulled across the top of the heater and into the hot line.

Ok, dip tube does not appear to be the problem. Now I am thinking it is the manifold. I did not drip the hot side and the next morning the hot side of all faucets did not run. After the thaw, no hot water just cold with pressure out the hot side of faucet. If I shutoff the cold intake to the HW heater, still cold with pressure at the hot faucets. I think the manifold chamber on the hot side froze and compromised the separator.

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Pic is not exactly right. I have a cold intake at the bottom with hot intake at top and cold outtake to hw heater at top. Just using the pic to show the chamber separator on the hot side.

Thoughts?