Another reduced hot water pressure question

I am on city water. Gas water heater 4 years old. There was a softener in the system until about 15 years ago.

Recently, the hot water pressure went down suddenly in every faucet. I flushed the water heater using full pressure cold water and got out about a cup of white granules. The problem remains.

Does anyone have experience adding vinegar to the water heater and running it through the pipes? Could a few treatments like this hurt? These are copper pipes about 30 years old.

Also, I ran all of the white granules through my fingers and there was some glycerin kind of feel to it. Makes me wonder if the city puts in something that precipitates or separates causing some kind of issue.

Is there a way to rule out a dip tube issue? Even if it is deteriorated, this would not affect hot water pressure, would it? If the goo in the granules is the result of dip tube decomposition, could replacing it eliminate this problem?

There is plenty of hot water, it's just lost horsepower.

 

Those granules are sand, calcium and other minerals. Flushing the tank won't improve pressure. A broken dip tube won't affect pressure. A partially plugged shutoff valve will do it. First make sure all the valves are open. Then close and reopen them.

Running vinegar thru the tank won't help and would take a while to flush out.

 

Nope, those flakes and granules in the bottom of your water heater are calcium that precipitates out of the water when it's heated. They are not intentionally added. Possibly the reason the house had a water softener. The goo is a harmless bacteria and has nothing to do with the dip tube.

Something is clogged and if it's affecting everything in the house then it could be a blockage before or after the heater though after is most common. If you open the drain valve at the bottom of the tank does it come out in great volume or does it seem reduced? If you have good flow at the heater the clog is likely downstream. Possibly one of the calcium flakes made it's way out of the tank and is stuck clogging a valve or a fitting.

 

When I drain the tank there appears to be full volume.

It all makes sense to me. I am wondering about pouring some vinegar into the tank, opening the faucets so that treated water gets into the pipes and then letting it remain in the pipes for a few hours before opening the faucets again.

Maybe this would dissolve some granules stuck at a fitting somewhere enough to allow water pressure to move them; I don't find any valves between the heater and the shutoffs at each fixture but there are a number of elbows and Ts. I have seen this approach mentioned a couple of places.

 

Flushing each and every faucet is what you should do first. Remove all aerators and nozzles from faucets and flush the pipes. If any of your faucets are cartridge types, remove and flush. I doubt a vinegar solution in the line will do much good.