Water Heaters - Drained the tank and now have low pressure and air in lines

A few days ago I noticed that I was running out of hot water while taking a shower. I wasn't but maybe a 15 minute shower, no longer than usual.

I immediately assumed there was something wrong with my hot water heater. I went down to my basemement to check to see if the pilot had blown out and it hadn't. The T-stat was already set to Very Hot.

I've been reading other Thread Posts to get an idea of what else it might be.

It's not my mixing valve on my shower because I have separate mixing valves for hot and cold and I also noticed I was running short on hot water the night before while washing dishes.

I tested my T-stat by dropping the setting to Hot, let it sit while I was at work, when I returned I cranked it back up to Very Hot and imediately my burner ignited. This leads me to believe that my T-stat is operating correctly.

Further investigation into my water heater I've discovered that my lines are attached to the wrong inlets and outlets, my hot is attached to the cold inlet and my cold is attached to the hot outlet of my water heater. Thus my dip tube is feeding my hot line and drawing water directly off the bottom of my tank. Unless the installer switched the location of the dip tube when installing it. I removed my temp/pressure release valve, which is located on the side of my tank, but couldn't tell if my dip tube was fully intact. I definately saw a pipe inside the tank which dropped down from where the hot water exits the tank. I was'nt able to disconnect the lines at the top of my tank, I need to get the right type of wrench. This being the case, it still does not make sense that I am just now running short on hot water for the first time in six months, since I've owned the place.

I drained my tank completely as described by Sharp Advice. I shut off my gas, closed my water main, tuned on the hot water at my kitchen sink and completely drained the tank. When I went to refill my tank, I closed the spigot and reopened my water main. Once I saw I was getting water from my kitchen sink, I turned it off. When the tank finished filling, I re-lit my pilot and cranked the setting up to Very Hot. After about an hour had passed, I turned on my water at my kitchen sink. It sputtered quit a bit and spit out some sediment and some brown water, as expected. I let the water run for a while, maybe 15 minuntes, everything seemed to be running fine except I noticed that I have less pressure now. Also, after about another half hour I turned the water on again to find the same sputtering and discolorations I found when I first turned it on. So it seems that from draining my tank, I now have less water pressure and can't seem to get the air out of the lines.

Can anyone help me with this problems?

I showered this morning as I usually do and didn't seem to run out of hot water. Maybe flushing my tank helped? I'm sceptical. I still think I need to switch my lines on my water heater.

My water heater is a 10 year old, 40 gal, gas. I can't remember the Manufacturer.

Well my first inclination is to say that because the hot water is exiting out the dip tube then a large piece of sediment could have lodged inside the tube. Before you do anything else you need to get the cold water on the inlet of the hot water heater. Nothing will be right until you do that.

And it is pointless to proceed further until you do... Of course, that's just my opinion.

That's what I was thinking myself. From my HWH I have about 2' of copper piping running up where it elbows into cast iron. I was having trouble getting my connections on my HWH and at the elbows undone, probably due to 10 years of corrosion and build-up. If in the end I can get them disconnected, could I simply replace them with flexible connections like I've installed below my bathroom sink? That would make it very simple to switch the hot and cold. The reason I ask is that I don't have to saudering tools needed to replace the copper piping.

Most likely you can simply (after turning off the water and draining it down some) cut the copper pipe with a hacksaw, and remove the adapter from the iron pipe. You may have to find the right 3/4 inch pipe nipples, then just connect them together with whatever grade of flexable pipe you desire... just make sure it is a quality pipe made for hot water heaters.

awd01,

Correct me if I'm not reading your post right. What I'm about to tell you is from having dealt with 3 WH that had the water lines installed backwards.

If you were getting 'normal' showers (15 to 20 minutes), and the DW was operating normally (had hot water all the way through all of its cycles, and then a few days ago, everything suddenly went south on you, then your water lines on top of the WH aren't reversed. If the lines WERE reversed, those indicators would have been present from day 1 when the house was brand new. Further, if the lines WERE reversed, you would only have enough hot water for about a 3 or 4 minute shower, at best.

Tell me how you came to the conclusion that the lines are reversed.

In all 3 cases where I have found them, they were visually perfect when you looked at the WH. The line on the right (cold) had a shut off valve above the WH and went to the right side nipple, marked with "cold" or a "C". The left side line had no shut off valve and went to the nipple on the left marked "hot" or "H". In one case, 2 licensed plumbers (one from each of 2 of the biggest shops in town) had actually REPLACED the WH, and neither was able to figure out that the installing plumber had the hot and cold lines reversed inside the wall. I know how I figured out that the WH was plumbed backwards -- how did you do it?? (At that time, I was just doing maintenance work for rental units as an unlicensed handyman, charging about $15 an hour.)

Is your low presure everywhere or just the sinks? Sinks clean the arators. Everywhere its probably clogged where the copper and galvinized pipes meet. You would have to change the nipple.

Thanks to all of you who replied. I appreciate the advice. I haven't done any more work on my water heater since draining it last Thursday. I seem to be having enough hot water for my showers in the morning so it has fallen a couple steps down on my list of priorities. I was in the middle of remodeling my bathroom when all this water heater trouble came about.

First I'd like to reply to Lefty's post.
The top of my hot water heater is clearly labeled, "HOT" on the left side and "COLD" on the right side. The line on the right side does have a shut off valve above it. My water heater is located in the unfinished portion of my basement where all piping is visible. When I trace this line on the left, labeled "HOT", it is clearly connected to my main supply line. When I trace the line on the right side, labeld "COLD", it is clearly serving the hot water line which leads up to my kitchen sink, as well as other hot water lines to my washing machine, etc. You're right in assuming that my lines can't be switched since I haven't had any troubles with getting hot water until just last week. It doesn't make sense to me either. Is it possible that the dip tube had been switched as well? If this is the case, would the system operate correctly?

As for Krankyolman's post.
I seem to be getting normal pressure in all locations at this time except my kitchen sink. I've already cleaned out the aerator in my kitchen sink and it didn't fix my problem.

I haven't had any more air in any of the lines and I've been getting normal pressure in most places, except the kitchen sink. I'm still getting very low pressure and also getting milky white water from my hot water in my kitchen sink only. What could have caused this and how can I fix it?

We still have an unclear situation here. You said there is a shut off valve on the rigth side...the side labeled cold. That is very normal. There should always be a valve on the cold inlet, and never on the hot outlet. Have you verified by touching the pipes while a hot tap is running, that the left is cold in and the right is hot out? If this is truly the case, it needs to be fixed. Also, at 10 years of age, your unit is in prime "dip-tube-lawsuit" age range. Go to the manufacturers website with your serial number. It could well be the dip tube is going and causing your symptoms.

awd01,

The dip tube inside the WH wasn't switched at installation.

To determine if indeed your WH is plumbed backwards, do this.

Close the shut off valve above the WH, then open the lever on the T&P valve. If the WH is plumbed properly, you will get water running out of the T&P tube for several seconds, and then the flow will taper off to nothing. Give it a full minute and see what happens. If indeed the WH is plumbed backwards, the flow out of the T&P tube will keep going at full pressure forever.

If you still have doubts, shut off the main water supply to the house. Bleed the pressure off of the entire system by opening a hose bibb or a cold valve in the bathtub. Go back to the WH and disconnect BOTH supply lines at the top of the WH. HAve an assistant open the main feed to the house and see just which supply line at the WH the incoming cold water comes out of. Reconnect THAT ONE to the cold nipple of the WH.

lefty/594tough
I am certain that my connections to my water heater are switched. Your questions made me second guess myself so I checked them again. They are undoubtably switched. Even so, this doesn't explain why the system has been running normal for so many years. I will switch my lines and check my dip tube's condition and replace it if needed. Do I need to fully drain my tank in order to do so? Also, I am still getting lower pressure and milky colored water from my hot tap at my kitchen sink location only. What could explain this?

I have had sediment lodge in the valve under the sink causing this same thing. the only real fix for it is to take the valve apart and let the sediment pass through the larger opening.

Do you have a sprayer? turn the hot on full. Pull the trigger release as fast as you can a few times. If it gets better do this every so often or take the diverter out for awhile.

awd01,

If the WH worked fine "for so many years", I seriously doubt that the lines are reversed. (Then too, you are looking at it -- I'M NOT!!) Feeding the cold water into the hot nipple of a WH is going to cause problems (short showers, etc.) that show up on DAY ONE, and they will NEVER get better!!