Learn Me: Hot Water Heaters

2yo electric HWH. No HW pressure in the house, well very minimal. HW though. CW has plenty of pressure. Pressure valve at the top has pressure as does the drain valve. Drain came so hard it could be in a porn. HW pressure has been decreasing for about 3 weeks and has never been good since the HWH swap. Pipe is hot all through the basement. It has not been cold enough (except last night) to freeze pipes. Separate from the house heating. Expansion tank shows that it is good on it's bubble telltale.

Did property maintenance with my father for about a decade and him longer, neither of us can figure this one out. I am looking at a cold shower iin the AM I think.

Came in to help but then I realized I only know about cold water heaters. Sorry!

I wonder if there is a problem with the little heat trap valve in the hot side pipe exit? It may have gotten melted during installation and is causing trouble now?

Did you try turning it off, then turning it back on? 

All HW outlets in the house are the same, pressure-wise?

Are there valves at the heater inlet and outlet?  Are they fully open?

barefootcyborg5000 said:

Came in to help but then I realized I only know about cold water heaters. Sorry!

Just to be a bit pedantic...

Water is never cold in a functioning water heater (except for the first time it is used).  Technically, a water heater doesn't heat cold water. It makes hot water hotter water. 😉

In reply to 1988RedT2 :

No HW now.

I did flick the breaker. 

I repair/rebuild valves for a living. All are working great.

Defining cold water is funny, it was one of the biggest things I missed when I lived in PR, but we still had a water heater. I have it here in a month or so.

I do think it may be in the outlet valve but still hot after it.

In reply to preach :

Wild guess especially where you mention the HW side pressure has been down since this heater was installed.  I'm thinking there may be a plastic dip tube inside the threaded HW connection at the top of the tank, it may have been overheated and deformed some if soldering was done close by the connection.  If it deformed enough it could restrict flow.

In reply to 11GTCS :

Perhaps, I will have to look again but the in and out valves are new. I did note an anomaly on the outlet valve so we will see.

Anyone want to see a New England basement that I go into once a year when I fire up the furnace? and I store a ton of E36 M3 in, I mean complete crap.

Our water heater had a habit of creating crusty blue mineral deposits that would occasionally accumulate and clog up anything that had fine passages (filter screens, kitchen spray heads, etc). Any chance yours is doing the same?

In reply to DarkMonohue :

All screens are clear. We actually do not run one in the kitchen since we use a remote dishwasher.

So, you're basically getting zero flow out of every hot water outlet in the house?  "Never been good since the heater swap."  If flow is good from the drain valve, gotta be an obstruction at the heater outlet, no?

In reply to 1988RedT2 :

Yes but unsure where. Asbestos walls so could get ugly.

I had to backflush hotwater lines once after replacing a water heater. Garden hose at the farthest point. Ymmv

jgrewe in above post probably told you what the problem is.    The little plastic heat trap piece that is inserted in the hot water exit pipe on the top of the heater.  It is either clogged with calcium, etc., or deformed.   I have removed them to solve the problem.

If the water is off and you open a faucet, do you get a one or two second blast of pressure and then i trickles down.  If so, there is an obstruction blocking a pipe somewhere. I have seen mineral build up at hot water pipe and fittings at top of water heater.  Seen rubber washers from valves dislodge and move to where they partially block the flow of water.  Are you on a well?  If so mineral deposits is most likely the issue.  If everything is effected the same way, then cut and remove hot water connection at water heater and start there.  If you are in a state that requires vacuum breakers on the hot side, unscrew the vacuum breaker and have a look down inside the fitting for crud.  Check your airators on the faucets and the screen on the shower heads.

In reply to tr8todd :

No blast, just maybe a trickle.

Waiting on a call back from a plumber, but heating season start up...

SV reX said:

barefootcyborg5000 said:

Came in to help but then I realized I only know about cold water heaters. Sorry!

Just to be a bit pedantic...

Water is never cold in a functioning water heater (except for the first time it is used).  Technically, a water heater doesn't heat cold water. It makes hot water hotter water. 😉

There's a reason they're abbreviated "HWH" on architectural plans, and not "CWH."

SV reX said:

barefootcyborg5000 said:

Came in to help but then I realized I only know about cold water heaters. Sorry!

Just to be a bit pedantic...

Water is never cold in a functioning water heater (except for the first time it is used).  Technically, a water heater doesn't heat cold water. It makes hot water hotter water. 😉

I disagree with that.

Every time the tank refills to replace use, it's taking water that is somewhere between 58-65dF and turning it into water that is somewhere around 110-120dF.

Most people sure wouldn't want to swim or take a shower in 65dF water, so I'd say that qualifies as "cold" water.

Here are some pics:

mixer valve

set up 

Above the mixer valve there is a ball valve shut off that also reduces pipe size to 1/2". It then splits kitchen and bathroom. Pipes are warm even after the split.

SV reX said:

In reply to Duke :

I disagree.

When cold water enters the tank it immediately mixes with the hot water in the tank and is no longer cold. The water heater does no work to achieve this.  It can be turned off and the immediate action of cold water turning into reasonably hot water will still happen instantly.

Disagree all you want, but you're not convincing me.

A typical tank water heater is about 60 gallons.  In the course of, say, a small load of laundry or a short shower, 20 gallons of 110 dF water will get replaced with 55 dF water.

That reduces the temperature from 110 dF to about 92 dF, cooler than body temperature.  I'll stake my semantic fight on that not being considered "hot" water. 

The existing pre-heated water is not "instantly" heating up that replacement water.  When the inlet valve opens, the temperature sensor is going to register lower than the target temperature and immediately kick on the fire or heating element.  The existing thermal mass helps pre-temper the water, but the heater itself will immediately come into action to restore the target temperature.  It's - wait for it - heating the cold water.

And that only gets more true if you take a bath or a longer shower.  If what you are saying is true, strictly speaking, no one would ever run out of hot water.  But for a typical residential water heater, it's not difficult to consume hot water much more quickly than that the unit can recover.

But I'm bored with this already, and it's not helping the OP one bit.

In reply to preach :

OK, the pictures help.  I have that exact water heater on the island and it's a good quality one.  My previous theory of too much heat on installation is out the window as I see all pipe thread connections or pro-press connections that don't require soldering / heat.

Can you manipulate the mixing valve?  Something is blocking flow out of the heater and from your previous posts you flushed the heater through the drain valve and had plenty of pressure.  I'm thinking the mixing valve is stuck closed or blocked somehow.   Are there isolation valves in the piping above the heater on the hot and cold lines?  If so it might be time to head for the "Depot" and grab some fittings to remove the mixing valve and bypass it to troubleshoot it.  The thermostats for the electric elements are under that sheet metal cover with the black label, there may be two of those covers as there are typically two elements one on top and another lower in the tank.  You can lower the thermostat settings to a safe setting to avoid scalding anyone in the short term.

EDIT: If you drain the tank make sure to shut the power off to the heating elements.  They will burn out quickly if they go dry.  There are live electrical connections on the thermostats so same to shutting off the power if you pull the covers.

In reply to preach :

My apologies for the disctraction.